JPH0579215B2 - - Google Patents

Abstract

PURPOSE:To obtain a laminated sheet containing no air bubble and high in the content of a base material by a method wherein a base material is partially impregnated with a resin solution so as to leave both side end parts thereof and the impregnated base material is heated under pressure while the penetration of the partially impregnated resin solution throughout the base material is achieved using a double belt press having substantially equal pressure over the whole region to be pressed. CONSTITUTION:A resin solution is partially infiltrated in each of a plurality of base materials at the central part thereof almost uniformly in the width direction thereof without fully filling the gaps of each base material 1 while both side parts each of which is 1-5% with respect to total area of the base material in the width direction thereof are left not to be impregnated. A plurality of the long base materials impregnated with the curable resin solutions are superposed mutually to be formed into a laminate. This laminate is heated under pressure by a double belt press 11 having substantially equal pressure over the entire region to be pressed and the impregnated resin heated under pressure fills the voids of the base materials as wide as possible to form a laminated sheet.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method for continuously manufacturing a laminated board suitable for various electrical insulations, printed circuit boards, etc., in particular. [Conventional technology] A long base material such as kraft paper is sufficiently impregnated with a thermosetting resin liquid without leaving any voids, and multiple sheets of this impregnated base material are stacked one on top of the other and heated with or without pressure. It has been conventional practice to continuously manufacture laminates by curing resin liquid. However, among these methods, curing without pressure forms a thermosetting resin layer between the base materials, and
The content of the base material in the resulting laminate is relatively low, and mechanical properties such as strength and rigidity tend to be insufficient. As a measure to solve this problem of insufficient base material content, as described above, multiple sheets of impregnated base materials that have been sufficiently impregnated without leaving any voids are stacked one on top of the other, and are then cured under pressure using a double belt press or the like. Ba,
It is possible to increase the base material content and reduce the resin content, but most of the impregnated resin is discharged from the base material when pressurized, which tends to contaminate surrounding machinery, and the amount of discharged resin is large, so the discharged resin Although it is necessary to recover the waste, the task is extremely difficult. [Problems to be Solved by the Invention] Therefore, in the present invention, an endless belt is constructed by impregnating a long base material with a thermosetting resin liquid and stacking a plurality of sheets of this impregnated base material. When heating and pressurizing a laminate with a large base material content using a double belt press, there is no discharge of the impregnated resin liquid to the pressurized surface of the equipment during pressurization, there is virtually no residual air bubbles, and the base material content is high. It is an object of the present invention to provide a method for manufacturing a laminate with a high [Means for Solving the Problems] In the present invention, a long base material essentially does not require a drying process, and substantially does not generate reaction by-products such as gas or liquid during the curing reaction process. In a continuous manufacturing method for a laminate, which includes an impregnation step of impregnating a thermosetting resin liquid, and a heating and pressing step of stacking a plurality of impregnated base materials and heating and pressing them to harden the resin liquid and integrate them. In the impregnation step, both sides of each of the plurality of base materials in the width direction of the base material are left unimpregnated by 1% to 5% of the total area on each side, and the void of each base material is left unimpregnated in the center part. 〓
Partially impregnated with the resin liquid almost uniformly without completely filling the area, and in the heating and pressurizing step, a double belt press composed of an endless belt is used, which has a substantially uniform pressure over the entire area of the pressurizing zone. , by applying heat and pressure while measuring the penetration of the partially impregnated resin liquid into the entire base material,
I tried to solve the above problem. The present invention will be explained in detail below. The long base material as used in the present invention is, for example, a glass fiber-based material such as a long glass fiber cloth or a glass nonwoven fabric, or a paper mainly composed of cellulose fibers such as kraft paper, aluminum hydroxide mixed paper, or linter paper. ,
Refers to a sheet or band-like material made of inorganic fibers such as asbestos cloth. When using paper as a sheet-like base material, from the viewpoint of impregnability and quality, it is preferable to use paper mainly composed of cellulose fibers, such as kraft paper, with a density (bulk specific gravity) of 0.3 to 0.7 g/cc when air-dried. . These substrates are impregnated and dried before being impregnated with a thermosetting resin liquid using a treatment agent such as methylol melamine, methylol phenol, methylol guanamine, or N-methylol compound to improve their water resistance and moisture absorption. This is preferable because electrical properties can be improved by reducing the electrical properties. The amount of treatment agent applied here is the base material (100 parts by weight)
The amount is usually 5 to 35 parts by weight. Furthermore, the thermosetting resin liquid referred to in the present invention essentially does not require a drying step and does not substantially generate reaction by-products such as gas or liquid during the curing reaction process.
In addition to conventionally known unsaturated polyester resins, diallyl phthalate resins, vinyl ester resins, and epoxy acrylate resins, it refers to side chain double bond type resins described below, which have unsaturated groups in their molecules. This resin is characterized by being crosslinked between unsaturated groups or via a crosslinking vinyl monomer, and also includes epoxy resins. These thermosetting resins are suitable because they are in a liquid state with low viscosity when impregnated into a substrate, and have good bonding properties with the substrate when cured after being impregnated into the substrate. The side chain double bond type resin has particularly excellent impregnating properties when used in combination with a crosslinking vinyl monomer. The side chain double bond type resin is a polymer composed of a main chain and a side chain, and the main chain is a backbone polymer containing a vinyl monomer unit having a functional group,
The side chain refers to a resin that is a branch having a radically reactive carbon-carbon double bond formed through a functional group of the main chain, and the vinyl monomer that constitutes the main chain of the side chain double bond type resin. A simple substance is one in which a vinyl monomer unit having a functional group is an essential unit, and if necessary, a vinyl monomer unit not having a functional group is included therein, and these are polymerized to form a main chain. Monomers constituting the above essential units include acrylic acid, methacrylic acid, maleic anhydride,
Vinyl monomers having a carboxyl group as a functional group such as maleic acid monoester, glycidyl methacrylate, vinyl monomers having a glycidyl group as a functional group such as glycidyl acrylate, and other vinyl monomers such as allyl alcohol, 2-hydroxyethyl methacrylate, 2-hydroxy Ethyl acrylate, 2-hydroxypropyl acrylate, N-
Vinyl monomers having a hydroxyl group as a functional group such as methylol acrylamide are typical examples, and acrylic acid and methacrylic acid are particularly preferred. Furthermore, the vinyl monomer unit having a functional group as used herein refers to the case in which it exists as an active functional group when the main chain is formed by polymerization, as well as the case in which the side chain described below is reacted with the functional group of the monomer in advance. Refers to a type of vinyl monomer unit that has a functional group that serves to form a side chain into the main chain, regardless of whether it is polymerized to form the main chain. Vinyl monomers without functional groups include styrene, α-methylstyrene, chlorostyrene,
vinyltoluene, vinyl chloride, vinylidene chloride,
Examples include vinyl bromide, acrylonitrile, ethylene, propylene, butadiene, acrylic ester, methacrylic ester, vinyl acetate, vinyl propionate, diester maleate, and ethylvinylbenzene. The weight average molecular weight of the main chain composed of these vinyl monomer units is from 5,000 to 400,000, preferably from 10,000 to 200,000. This value is appropriately selected depending on the type of side chain. The physical properties of this molecular weight as a laminate for printed circuit boards or an electrically insulating laminate affect the impregnation properties; if it is less than 5,000, the mechanical properties of the laminate after curing will be insufficient, and if it exceeds 400,000, the substrate Both are unfavorable as they have poor resin impregnation properties.
In addition, the amount of monomer units having functional groups in the main chain is related to the density of the side chains and affects the curing reactivity between side chains, so an appropriate ratio is selected, but the density of side chains in 1000 g of the main chain is The amount is preferably 0.1 to 2 mol, more preferably 0.4 to 1.5 mol. The side chain referred to in this side chain double bond type resin means >C=C< at the end or in the middle.
It refers to those that have a double bond that forms a structure through the functional group in the main chain, but if a crosslink can be formed between the side chains by a radical reaction with a crosslinked vinyl monomer. applicable. Various methods can be employed to introduce a side chain having a double bond at the end of the side chain into the polymer constituting the main chain in this side chain double bond type resin. Some examples are as follows. (a) One epoxy group of a compound having a diepoxy group, such as the diglycidyl ether type epoxy group of bisphenol, is reacted with the carboxyl group of the main chain functional group, and the remaining epoxy group is reacted with acrylic acid or methacrylic acid. react. (a) The carboxyl group of the main chain functional group and glycidyl acrylate or glycidyl methacrylate are subjected to an ester reaction. (c) The epoxy group of the main chain functional group is subjected to an ester reaction with methacrylic acid or acrylic acid. (d) A diisocyanate compound is reacted with hydroxyethyl (meth)acrylate to create a reaction product that is mainly composed of monoisocyanate and contains almost no diisocyanate compound, and the isocyanate contained in this reaction product is reacted with the hydroxyl group of the main chain polymer. let In the exemplified method, the main chain was copolymerized first, but it goes without saying that the reaction to form the side chain is performed first, and these monomers are finally monopolymerized or copolymerized to form an acryloyl group at the end of the side chain. Alternatively, a side chain double bond type resin containing a methacryloyl group may be produced. In addition, crosslinking vinyl monomers include styrene, vinyltoluene, chlorostyrene, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate,
lauryl methacrylate, benzyl methacrylate,
Dibutyl maleate, dioctyl maleate, vinyl acetate, vinyl propionate, divinylbenzene and the like are included. These monomers may be used in combination of two or more. Furthermore, if necessary, a halogen-containing flame retardant imparting component and a flame retardant aid such as phosphoric acid ester, antimony trioxide, or aluminum hydroxide may be added to the thermosetting resin liquid used for impregnating the base material. It's okay. In addition, when using any thermosetting resin liquid, its viscosity can be appropriately selected depending on the purpose of use of the laminate to be manufactured, the pressure during pressure molding, etc., but it is usually 0.05 ~ 0.05 at 25 ° C. Approximately 500 poise is suitable; if it exceeds 500 poise, impregnating properties of the base material are poor and air bubbles are likely to remain in the resulting laminate. Moreover, if it is less than 0.05 poise, the impregnating property is good, but there is a problem that it is easily affected by the intrusion of external air. Then, the elongated base material is partially impregnated with such a thermosetting resin. That is, in the partial impregnation, 1% to 5% of both sides of each of the plurality of base materials are left unimpregnated with respect to the total area in the width direction of the base material, and the voids of each base material are left unimpregnated in the central part. 〓 is partially impregnated with the resin liquid almost uniformly without filling the entire area. When kraft paper is used as an example of a base material, the vacancy of kraft paper is usually 60 to 70% by volume (when air-dried), but this vacancy is, for example, about 30 to 45% by volume, and the impregnated portion of the base material is It impregnates only the central part of the base material in the width direction so that it can be impregnated at any position. The unimpregnated part is 1 on one side of the total area in the width direction.
% or less, the discharged resin liquid will not be completely absorbed by the unimpregnated base material and will be discharged to the outside of the base material, contaminating the equipment. On the other hand, 5% or more is not only necessary for absorbing the discharged resin liquid, but also causes a large loss of the base material.
This is undesirable because the width of the endless belt increases, leading to an increase in equipment costs. Impregnation of these long substrates with the cured resin liquid is carried out by appropriately selecting a known method such as a partial coating method or a partial dipping method. For example, as shown in FIGS. 1 and 2, a plurality of base materials 1 are sent out, and a partial coating nozzle 2 is used to apply the resin liquid to only the central portion of the base materials 1 as described above. Apply and base material 1...
As shown in FIG. 2, in each base material 1, a resin-impregnated part 3 in the center part and non-resin-impregnated parts 4, 4 on both sides are formed to form an impregnated base material 5. shall be. In addition, the amount of impregnation of the curable resin liquid is related to the pressure applied during the next process with the double belt press, and it is important to ensure that the pressure does not cause excessive flow to be discharged outside the base material and that the resulting laminate is Adjusted so that air bubbles are substantially absent, and the amount of resin liquid discharged from the base laminate to the unimpregnated portions at both ends when pressurized with a double belt press is 3% or less of the amount of cured resin in the product laminate; It is desirable that the amount is preferably 1% or less. If the amount of impregnation is less than the appropriate amount for the pressure at the time of pressurization, air bubbles will remain in the resulting laminate, causing an overall whitening phenomenon. The elongated base material impregnated with the curable resin liquid in this way is stacked together to form a laminate, and then pressed using a double belt press that applies substantially uniform pressure over the entire pressure zone. The impregnated resin is heated and pressurized to fill the voids in the base material as widely as possible to form a laminate. The double belt press according to the present invention, which is composed of an endless belt that exerts substantially uniform pressure over the entire pressure zone, is a double belt press in which endless belts made of stainless steel with a thickness of about 1 mm are installed above and below, for example. A base material impregnated with resin liquid is sandwiched between the upper and lower belts and can be heated and pressurized.
The structure is such that the pressure of the pressure band is substantially uniform. To give a specific example, (1) A plurality of rows of roll pairs are arranged to sandwich the upper and lower belts and apply pressure to the belts, and the roll diameter is 50 mm or less and the ratio of the roll pitch to the roll diameter is 1.2. This method reduces the pressure drop between adjacent rolls by doing the following: The rolls may be placed in fixed positions, or they may be placed between pressure plates installed above and below the endless belt and the endless belt. , may revolve around the pressure plate. The diameter of the roll increases,
If the distance between the rolls is too large, large waves will occur in the pressure applied to the substrate, which is undesirable. (2) A system in which the upper and lower endless belts are sandwiched, a pressure plate is placed to apply pressure to the belt, and a pressure medium is press-fitted and circulated between the pressure plate and the endless belt for the purpose of lubrication. (3) A container for storing pressure medium is created by sandwiching the upper and lower endless belts, and the opening of this container is in contact with the endless belt, and the pressure medium directly presses the endless belt. This formula is particularly suitable because the pressure difference across the entire pressure zone is small. What is shown in FIG. 1 is an example of this pressure medium storage type double belt press. This double belt press 11 has drums 12, 12a
, endless belts 13, 13, and pressurizing chamber 14
and a pressure medium 15 made of high-temperature fluid, and the pressure medium supply device 16 includes a pump 17
and a heater 18 are connected by a plumbing pipe 19. Drums 12, 12 and 12a, 1
2a consists of a pair of upper and lower drums that rotate in opposite directions to each other along the traveling direction of the impregnated base material 5;
Endless belts 13, 13 are tensioned between drums 12, 12a arranged in parallel on one side of the impregnated base material 5 and rotating in the same direction. A pressure medium 15 is filled behind the endless belts 13, 13 for applying the heat and pressure necessary for curing the resin impregnated into the impregnated base material 5 and integrating the impregnated base material 5. A pressurizing chamber 14 is provided. This pressurizing chamber 14 is a container of any shape, and one of its constituent surfaces is constituted by the endless belt 13. Inside this pressurizing chamber 14, an impregnated base material 5 is inserted from the endless belt 13. A pressure medium 15 for applying heat and pressure is press-fitted. Furthermore, the pressurizing chamber 14 has a pressure medium 1
5 and a pressure medium 15
A pressure medium supply device 16 is disposed in which a heater 18 such as an electric heater that heats the pressure medium is connected through a piping 19 . Note that the heater 18 may be incorporated into this pressurizing chamber 14. The pressure medium 15 is circulated between the pressure medium supply device 16 and the pressurizing chamber 14 by a pump 17, and the pressure medium 15 can be replenished, pressurized, and heated from outside the pressurizing chamber 14. There is. The inside of the pressurizing chamber 14 can be heated indirectly by heating the pressure medium 15 with the heater 18 .
Furthermore, the same amount of pressure medium 1 flows out of the pressurizing chamber 14 as the endless belts 13, 13 run.
5 is sequentially pressurized and supplied into the pressurizing chamber 14 by the pump 17, so that the pressure within the pressurizing chamber 14 is kept constant. The impregnated base material 5 sandwiched between the endless belts 13, 13 has a pressure medium 15 press-fitted into the pressurizing chamber 14.
The impregnated resin liquid spreads uniformly, fills the void, and is cured and integrated. The pressure medium 15 may be any fluid as long as it exhibits fluidity under the operating conditions of the double belt press 11. Examples of the gas medium include air, nitrogen, etc.
Examples of the liquid include lubricating oil, heat transfer oil, cylinder oil, etc., examples of the wax and low melting point polymer include polyethylene wax and paraffin, and examples of the low melting point metal include solder and wood metal. Regardless of the type of double belt press, the presence of a large pressure distribution, especially the presence of large pulsating pressure in the direction of movement, makes it difficult to selectively discharge air bubbles in the resin liquid-impregnated base material. In addition, re-intrusion of air into the pressure zone is likely to occur and should be avoided. For example, the pressure distribution is preferably ±50% or less and ±5 Kg/cm ² or less. Further, the applied pressure varies depending on the curable resin liquid used and the type of base material, but is appropriately selected in order to control the base material content in the obtained laminate. Usually 10Kg/cm ² G to 100Kg/cm ² G,
Preferably it is 10Kg/cm ² G to 50Kg/cm ² G. When the pressure is lower than 10 Kg/cm ² G, not only is it difficult to increase the base material content, but also the air evacuation effect is small and the laminate is likely to have air bubbles mixed in. On the other hand, the pressure is 100
If it is larger than Kg/cm ² G, it is not only unnecessary for removing air bubbles, but also the base material content in the resulting laminate becomes too large, which tends to cause deterioration in strength such as delamination. Further, the temperature used for hot-press molding varies depending on the type of thermosetting resin liquid used, the type of curing catalyst, etc., but is generally in the range of 50°C to 200°C.
At temperatures below 50°C, the time required for curing is too long and is uneconomical; at temperatures above 200°C, curing progresses rapidly, causing problems such as internal distortion and foaming. When pressurized by such a double belt press, the resin liquid in the laminate of multiple base materials partially impregnated with thermosetting resin liquid is applied to the non-impregnated base materials by the pressure applied. It penetrates into the parts and becomes uniformly impregnated in the thickness direction of the laminate. this is,
At the inlet of the double belt press, a large pressure gradient occurs in the laminate in the opposite direction to the direction of travel of the laminate, and this pressure gradient promotes penetration and impregnation of the resin liquid into the unimpregnated portion of the base material, and This is presumed to be because the replacement between the bubbles remaining in the resin liquid and the resin liquid is promoted. A portion of the displaced air bubbles are then continuously driven through the base material laminate in a direction opposite to the traveling direction, and continue to be removed from the laminate under pressure. In addition, some of the air bubbles are driven to both side edges of the laminate by the pressure gradient that also occurs in the width direction of the laminate, and the air bubbles are removed as a small amount of resin liquid is discharged from the non-resin-impregnated area. , this results in a laminate substantially free of air bubbles. Furthermore, since the thermosetting resin liquid is partially impregnated into the base material, discharge of the resin liquid from the base material laminate can be completely eliminated even when pressurized by a double belt press. . In other words, since the base material can be partially impregnated with only the amount of resin liquid corresponding to the resin in the resulting laminate, the excess resin liquid is
This is because it becomes possible to make the state in which it does not exist in the laminate even before pressurization. If the resin liquid is not discharged, there is no need to collect it in the double belt press, and the double belt press will not be contaminated, and the structure of the double belt press can be simplified. Therefore, as shown in FIG. 2, in the laminate after passing through the pressurizing chamber 14, a resin cured part 6 is formed that is wider in both directions than the width of the resin-impregnated part 3, and Non-resin-impregnated and non-cured portions 7, 7, which are narrower than the portion 4, are formed on both sides of the resin-cured portion 6. The base material content in the laminate thus obtained varies depending on the base material used, the type of thermosetting resin liquid, pressing conditions, etc., but is usually 30% by weight.
For example, when kraft paper is used as the base material and the aforementioned side chain double bond type resin is used as the thermosetting resin liquid, the amount ranges from 35 to 65% by weight.
If it is less than 35% by weight, the mechanical strength and bending rigidity of the laminate will be insufficient, and if it is less than 65% by weight, it is undesirable.
Exceeding this not only makes delamination more likely to occur, but also
This is disadvantageous because punchability and moisture resistance deteriorate. On the other hand, in order to manufacture metal foil-clad laminates, metal foil is overlaid on one or both sides of the laminate of impregnated base materials at the same time or a little later than the overlapping of the base materials, and this is then fed to a double belt press. It is done by folding. The metal foil used here is electrolytic copper foil intended for use in printed circuit boards, and it is preferable to use this from the viewpoints of corrosion resistance, etching properties, and adhesion, but other metal foils include electrolytic iron foil and aluminum foil. is also used. Metal foil with a thickness of 10 to 100 μm is usually used. Moreover, it is more preferable that the adhesive surface of the metal foil is roughened for the purpose of improving adhesiveness. In order to effectively achieve adhesion between the metal foil and the resin-impregnated base material, it is preferable to use an adhesive.
The adhesive is preferably a liquid or semi-fluid adhesive that does not generate unnecessary reaction by-products during the curing process, that is, an adhesive that preferably has a viscosity of 5000 poise or less. From this viewpoint, for example, epoxy-acrylate adhesives, epoxy resin adhesives, polyisocyanate adhesives, or various modified adhesives thereof are suitable. As the epoxy adhesive, a mixture of a bisphenol A type epoxy resin and a curing agent such as a polyamide resin or amines is suitable. By introducing such an adhesive, it is possible to produce a metal foil-clad laminate that has excellent adhesion strength of metal foil, as well as excellent solder heat resistance and electrical insulation properties. When using the adhesive applied to metal foil, heat-treat it at 60-150℃ for 2-7 minutes after application.
It may be precured to a semi-cured state. The adhesive can also be applied to the laminate at the same time. The thickness of the adhesive film may be about 10 to 100 μm, especially
20-50 μm is suitable. The thickness of the laminate obtained by the present invention depends on the type of base material,
The thickness varies depending on the composition of the thermosetting resin liquid, the use of the laminate, etc., but it is usually 0.5 to 3.0 mm. [Examples] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples unless it departs from the gist of the present invention. Throughout this specification, all temperatures are in degrees Celsius, and parts and percentages are by weight unless otherwise specified. (Preparation of side chain double bond type resin) Methacrylic acid (35 g, 0.41 mol), methyl ethyl ketone (400 g), and styrene were placed in a separable flask (3000 ml) equipped with a stirrer, a thermometer with a gas inlet tube, a reflux condenser, and a dropping funnel. Monomers (800 g, 7.7 mol), azobisisobutyronitrile (5.0 g) and dodecyl mergaptane (12 g) were charged, and polymerization was carried out at 75 to 80° C. for 10 hours under a nitrogen atmosphere. Hydroquinone (0.5g) was added to inhibit polymerization. The polymerization rate of styrene monomer was 76%, and the polymerization rate of methacrylic acid was 93%, and a polymer content containing a styrene-methacrylic acid copolymer having a weight average molecular weight of about 50,000 was obtained. In addition, in another reactor with the same configuration as above, "Epicote 827" (trade name of epoxy resin, manufactured by Yuka Ciel Epoxy Co., Ltd.) (360 g, 1 mol), methacrylic acid (138 g, 1.6 mol), benzyldimethylamine (1.2 g), parabenzoquinone (0.12g),
The reaction was carried out at 120° C. for 3 hours under a nitrogen atmosphere. After the reaction, the acid value became almost zero, and a vinylation reagent containing an epoxy resin containing an unsaturated group was obtained. Add the entire amount of the previously prepared polymer-containing liquid to the vinylization reagent,
Triphenylphosphine (5 g) and parabenzoquinone (0.10 g) were added and heated, the methyl ethyl ketone solvent was distilled off at a boiling point of 110°C, and the mixture was reacted at the same temperature for 5 hours. After the reaction, the content of the unsaturated group-containing epoxy resin was about 15% of that before the reaction. Styrene monomer (1000
While adding g) intermittently, heating evaporation was continued at 30-50 mmHg. The operation was terminated when the amount of methyl ethyl ketone detected in the distillate was 0.1% or less. The thus obtained resin liquid containing the curable prepolymer was a yellowish brown liquid with a viscosity of 6.12 poise (at 25°C) and a nonvolatile content of 52% by weight. (Examples and Comparative Examples) Commercially available long kraft paper (weighing 135 g/m ² , density
Using 8 treated substrates impregnated with 100 parts by weight of N-methylolmelamine (Nicaresin S-305 manufactured by Nippon Carbide Co., Ltd.) to a coating amount of 20 parts by weight (0.49 g/cm ² ) and dried, a curing catalyst was applied. After continuously impregnating the above-mentioned side chain double bond type resin liquid, unsaturated polyester resin liquid, and epoxy resin liquid in a predetermined manner and amount, the outermost layer is coated with an epoxy resin adhesive if necessary. Laminate electrolytic copper foil with a thickness of 35 μm, and
Using a pressure medium storage double belt press as shown in the figure, the material was continuously pressurized and heated at 100°C for 5 minutes, and then cured at 120°C for 1 hour to obtain a laminate and a single-sided copper-clad laminate. The results are shown in Table 1. In addition, among the "impregnation methods" in Table 1, "partial impregnation (A)"
This means that each of the eight base materials is impregnated with the thermosetting resin to the same extent as a whole, but the entire width of the base material is not impregnated with the resin liquid, and both ends are left unimpregnated. , using a coating device (slit nozzle). “Partial impregnation (B)” means that by curving the base material into a U-shaped cross section during impregnation, the center part of the base material is completely impregnated with resin liquid, and both sides of the base material are filled with resin liquid. A type of laminated material that is not impregnated at all. "Complete impregnation" means that all eight substrates are completely impregnated by the dipping method. In addition,
For any partial impregnation, for a paper width of 1070 mm,
This was done by coating and impregnating a 1030 mm width with resin liquid.

【table】

〔Effect of the invention〕

As explained above, the method for continuously manufacturing a laminate of the present invention essentially does not require a drying process and substantially eliminates reaction by-products such as gas and liquid during the curing reaction process. A laminate that has an impregnation process in which a thermosetting resin liquid that does not occur on a laminate plate is impregnated with a thermosetting resin liquid that does not generate heat, and a heating and pressing process in which multiple sheets of impregnated base materials are piled up and heated and pressed to harden the resin liquid and integrate them. In the continuous manufacturing method, in the impregnation step,
The resin liquid is partially impregnated into the base material leaving both side ends, and in the heating and pressing step, the part is impregnated using a double belt press having a substantially uniform pressure over the entire pressure zone. Since the method involves heating and pressurizing the impregnated resin liquid while measuring its penetration into the entire base material, there is a problem of contamination because all of the impregnated resin liquid discharged during pressurization with a double belt press is absorbed into both ends. It is possible to continuously produce a laminate with a high base material content that does not generate air bubbles and is substantially free of air bubbles.

[Brief explanation of drawings]

FIGS. 1 and 2 are schematic configuration diagrams showing an example of a manufacturing apparatus used in the present invention. 1... Base material, 2... Nozzle for partial application, 3...
Resin-impregnated part, 4... Resin-non-impregnated part, 5... Impregnated base material, 11... Double belt press.

Claims (1)

[Scope of Claims] 1. A thermosetting resin liquid that essentially does not require a drying process and that does not substantially generate reaction by-products such as gas or liquid during the curing reaction process is applied to a long base material. In the continuous production method of a laminate, the method includes an impregnating step of impregnating the base material, and a heating and pressing step of stacking a plurality of impregnated base materials and heating and pressing them to cure and integrate the resin liquid, in which: For each of the plurality of base materials, 1% to 5% of each side of the total area in the width direction of the base material is left unimpregnated, and approximately 1% to 5% of each side of the base material is impregnated in the center without completely filling the voids of each base material. Partial impregnation is carried out uniformly with the resin liquid, and in the heating and pressing step, the partial impregnation is carried out using a double belt press constituted by an endless belt that has substantially uniform pressure over the entire pressure zone. A continuous manufacturing method for a laminate, characterized in that the resin liquid permeates into the entire base material and is heated and pressurized to prevent the resin liquid from being discharged outside the base material. 2. The continuous production method of a laminate according to claim 1, wherein the laminate is a metal foil-clad laminate formed by laminating a plurality of base materials impregnated with metal foil simultaneously or in a separate process. 3. A double belt press consisting of an endless belt that has a substantially uniform pressure over the entire pressure zone, has a pressurizing chamber with the endless belt as one constituent surface, and uses a fluid as a pressure medium. The continuous manufacturing method of a laminate according to claim 1, which is a press. 4. The continuous production method of a laminate according to claim 1, wherein the pressure in the heating and pressing step is in the range of 10 to 100 Kg/ ^cm2 . 5. The method for continuously manufacturing a laminate according to claim 1, wherein the base material is paper.