JPH02143857A - Continuous manufacture of laminated sheet - Google Patents

Abstract

PURPOSE:To form a laminated sheet which is practically free from residual bubbles and has high base material content, by a method wherein the base material is heated and pressurized while contriving infiltration of an impregnating resin solution into the whole of the base material by making use of a double belt press constituted of an endless belt. CONSTITUTION:A thermosetting resin solution which does not generate a reactive by-product such as gas or a liquid is infiltrated into a long-sized base material 1. Then a plurality sheets of the base materials impregnated with the resin are piled upon each other, the resin solution is cured through heating and pressurization and unified. The above-mentioned impregnating process and heating and pressurization process are arranged almost vertically to each other and partial impregnation of the base material 1 with the resin solution 3 is performed in the impregnation process. Infiltration of partial impregnation of the resin solution 3 into the whole of the base material 1 is contrived by making use of a double belt press 11 possessing practically even pressure extending over the whole sphere of a pressurizing zone, in the heating and pressurizing process. Then since heating and pressurization, are performed, discharge of the impregnating resin solution other than small quantity of adhesion amount is streamed down with action of gravity and recovered at the time of the pressurization with the double belt press 11. Therefore, problem of contamination is not generated and a laminated sheet which is free from the bubbles and having high content of the base material can be formed continuously.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for continuously producing 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 thermosetting resin liquid without leaving any voids, and multiple sheets of this impregnated base material are stacked together and the resin liquid is cured by applying pressure or heating without applying pressure. Conventionally, it has been conventional to continuously manufacture laminates.

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, resulting in poor strength and They tend to lack mechanical properties such as rigidity.

In order to solve this problem of insufficient base material content, there is a method in which multiple sheets of impregnated base materials that are sufficiently impregnated without leaving any voids are stacked together and cured under pressure using a double belt press, etc., as described above. , 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 discharge is huge, so it is difficult to discharge. Although it is necessary to recover the resin, there is the disadvantage that 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 pressing with a double belt press to obtain a laminate with a large base material content,
To provide a method for manufacturing a laminate in which an impregnated resin liquid discharged from a base material during pressurization is quickly removed from a pressurizing surface of a device, has substantially no residual air bubbles, and has a high base material content. The purpose is to

[Means to solve the problem]

In the present invention, a long base material is impregnated with a thermosetting resin liquid that essentially does not require a drying process and does not substantially generate reaction by-products such as gas or liquid during the curing reaction process. In the continuous production method of a laminate, the method includes a heating and pressing step of superimposing a number of impregnated base materials and heating and pressing them to harden and integrate the resin liquid, in the impregnation step, each impregnating the base material with the resin liquid almost uniformly in the width direction, and in the heating and pressurizing step, having a substantially uniform pressure over the entire area of a pressure band installed approximately vertically above the impregnating step; The above problem was solved by heating and pressurizing the impregnated resin liquid while measuring the penetration of the impregnated resin liquid into the entire base material using a double belt press constituted by an endless belt.

The present invention will be explained in detail below.

The elongated base material as used in the present invention is, for example, elongated glass fiber cloth, glass fiber-based material such as glass nonwoven fabric, kraft paper,
It refers to paper made mainly of cellulose fibers such as aluminum hydroxide mixed paper and linter paper, and sheets or strips made of inorganic fibers such as asbestos cloth. When using paper as a sheet-like base material, from the viewpoint of impregnability and quality, paper mainly composed of cellulose fibers with an air-dried density (bulk specific gravity) of Ot 3 to 0.7 g/cc, such as kraft paper, is recommended. is preferred.

Before impregnating these base materials with thermosetting resin liquid, they can be impregnated and dried using a treatment agent such as methylol melamine, methylol phenol, methylol guanamine, or N-methylol compound to improve their water resistance and absorb moisture. This is preferable because electrical properties can be improved by reducing the electrical properties.

Here, tfffi to which the treatment agent is applied is the base material (100 parts by weight)
The amount is usually 5 to 35 parts by weight.

In addition, the thermosetting resin liquid referred to in the present invention that essentially does not require a drying process and does not substantially generate reaction by-products such as gas or liquid during the curing reaction process is a conventionally known unsaturated polyester resin liquid. In addition to resins, diallyl phthalate resins, vinyl ester resins, and epoxy acrylate resins, these resins include side chain double bond type resins described below. It is a resin that is characterized by being crosslinked between saturated 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 above-mentioned side chain double bond type resin is a polymer composed of a main chain and a side chain, where the main chain is a backbone polymer containing vinyl monomer units having a functional group, and the side chains are It refers to a resin that has a radically reactive carbon-carbon double bond that is configured through a functional group, and the vinyl monomer unit that makes up the main chain of a side chain double bond type resin has a functional group. Vinyl monomer units are essential units, and if necessary, vinyl monomer units without functional groups are included, and these are polymerized to form the main chain. Monomers constituting the above essential units include vinyl monomers having a carboxyl group as a functional group such as acrylic acid, methacrylic acid, maleic anhydride, and maleic acid monoester;
Vinyl monomers having a glycidyl group as a functional group such as glycidyl methacrylate and glycidyl acrylate, and other functional groups such as allyl alcohol, 2-hydroxyethyl methacrylate, 2-hydro-cow diethyl acrylate, 2-hydroxypropyl acrylate, and N-methylol acrylamide. Typical examples include vinyl monomers having a hydroxyl group, with acrylic acid and methacrylic acid being 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 with 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.

Examples of vinyl monomers without functional groups include styrene,
α-methylstyrene, chlorostyrene, vinyltoluene, vinyl chloride, vinylidene chloride, vinyl bromide, acrylonitrile, ethylene, propylene, butadiene, acrylic ester, methacrylic ester, vinyl acetate, vinyl propionate, diester maleate, ethyl vinyl Examples include benzene. These vinyl monomers 11
The weight average molecular weight of the main chain composed of 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. This molecular weight affects the physical properties and impregnability of laminates for printed circuit boards or electrical insulation laminates; if it is less than 5,000, the mechanical properties of the laminate after curing will be insufficient; If it exceeds this, the impregnating property of the resin into the base material will be poor, which is not preferable. 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 0.1~
The amount is preferably 2 mol, more preferably 0.4 to 1.5 mol. The side chain referred to in this side chain double bond type resin is one that has a double bond >C=C at the end or in the middle, and has branches in the main chain via the functional group. However, it can be applied as long as a crosslink can be formed between the side chains by a radical reaction using a crosslinking vinyl monomer.

In this side chain double bond type resin, various methods can be employed to introduce a side chain having a double bond at the end of the side chain into the polymer forming the main chain. Some examples are as follows.

(a) One epoxy group of a compound having a jepoxy 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. Avoid reactions.

(a) The carboxyl group of the main chain functional group and glycidyl acrylate or glycidyl methacrylate are subjected to an ester reaction.

(1) The epoxy group of the main chain functional group is subjected to an ester reaction with methacrylic acid or acrylic acid.

(1) Hydroxyethyl, (
A reaction product containing monoisocyanate as a main component and almost no diisocyanate compound is prepared by reacting meth)acrylate, and the incyanate contained in this reaction product is reacted with the hydroxyl group of the main chain polymer.

In the exemplified method, the main chain was copolymerized first, but it goes without saying that the reaction for forming the side chain was first carried out, and these monomers were 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.

Vinyl monomers for frame m include styrene, vinyltoluene, chlorostyrene, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and methacrylic acid. Examples include lauryl, benzyl methacrylate, dibutyl maleate, dioctyl maleate, vinyl acetate-11 propionate, divinylbenzene, and the like. These monomers may be used in combination of two or more.

Note that the thermosetting resin liquid used for impregnating the base material may contain a halogen-containing flame retardant component and a flame retardant aid such as phosphoric acid ester, antimony dioxide, or aluminum hydroxide, if necessary. Also good.

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 0.0001 at 25°C. Approximately 0.05 to 500 poise is suitable;
If it exceeds 0 poise, the impregnating properties of the base material will be poor and air bubbles will tend to remain in the resulting laminate. Moreover, if it is less than 0.05 Boise, the TL content is good, but it is easily affected by the intrusion of outside air.

Next, the elongated base material is impregnated with such a thermosetting resin. Partial impregnation is preferred as this impregnation method.

That is, the partial impregnation is to partially impregnate each base material with the resin liquid almost uniformly in the width direction without filling all the voids. When graft paper is used as an example of the base material,
Voids in kraft paper are usually 60 to 70% by volume (when air-dried)
However, the impregnation is performed so that the porosity is, for example, about 30 to 45% by volume at any position of the impregnated portion of the base material. The required amount of resin to fill the voids varies depending on the pressure of the molding, but if the amount of resin is excessive or less than 1%, the resin liquid will be partially insufficient, causing whitening.

On the other hand, 50% or more is not only unnecessary for resin liquid impregnation, but also makes it difficult to flow down due to gravity, increasing the amount of resin flowing to the side of the device, making it easy to contaminate the device.

Impregnation of the curable resin liquid into these elongated substrates is carried out by appropriately selecting a known method such as a dipping and squeezing combination method or a coating method. For example, as shown in FIG.
Using the dipping tank 2... and the spacer 5 which opens between each base material and allows the resin to flow in, the base material l is immersed in the resin liquid as described above, and then the resin is further soaked. Partial impregnation of the base material l is performed by discharging unnecessary resin with the M adjusting roll 6. As shown in FIG. 1, in each base material 1, the resin-impregnated base material 3 by dipping is laminated and integrated with a resin amount adjusting roll 6 to form an impregnated laminated base material 4.

In addition, the impregnation m of the curable resin liquid is related to the pressure during pressurization in the tuple belt press in the next step, and the pressure allows a laminate of a predetermined thickness to be obtained and substantially eliminates air bubbles in the resulting laminate. The amount of resin liquid discharged from the base laminate backwards and upstream by XL when pressurized with a tuple belt press is preferably 50% or less of the amount of cured resin in the product-laminate. It is desirable that it be 10% or less. If the amount of impregnation is less than the appropriate amount for the pressure during pressurization, air bubbles will remain in the resulting laminate, causing an overall whitening phenomenon.

The long material impregnated with the curable resin liquid in this way is stacked together to form a laminate, and then placed in a vertical shape above the dipping tank, covering the entire area of the dipping zone. The impregnated resin is heated and pressurized by a tuffle belt press having a substantially uniform pressure over the entire length, filling 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 that is constructed by installing stainless steel endless belts with a thickness of about IRl above and below, for example. , a base material impregnated with a resin liquid is sandwiched between upper and lower belts so that it can be heated and pressurized, and has a structure that allows the pressure of the pressure band to be substantially equal. 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 5'0xttt or less and the roll pitch and roll diameter are equal to each other. This method reduces the pressure drop between adjacent rolls so that the ratio is 1.2 or less, and the position of the rolls may be fixed, or the endless belt may be connected to pressurizing plates installed above and below the endless belt. It may be placed between the two and revolve around the XX pressurizing slope. If the diameter of the rolls becomes large and the distance between the rolls is too large, the pressure applied to the base material will be undesirably large.

(2) A type 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 the 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 a double belt press of this pressure medium storage type. This double belt press 11 is roughly composed of a drum 12.12a, an endless belt 13.13, a pressurizing chamber I4, and a pressure medium 15 made of high-temperature fluid. 18 are connected by a plumbing pipe 19. Drum 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, and drums 12. Endless belts 13 and 13 are tensioned between each of the belts 12a.

And for Ni& of this endless belt 13.13,
Curing of the resin impregnated into the impregnated base material 5... and the impregnated base material 5
A pressurizing chamber 14 is provided, which is filled with a pressure medium 15 for adding the heat and pressure necessary for the integration of.... This pressurizing chamber 14 is a container of any shape, and its structural surface is constituted by the above-mentioned endless belt I-13. A pressure medium I5 for applying heat and pressure to 5... is press-fitted. Further, the pressurizing chamber 14 is equipped with a pressure medium supply device 1 configured by a pump 17 for supplying a pressure medium 15 at a constant rate, and a heater 18 such as an electric heater for heating the pressure medium 15, which is connected through a piping 19.
6 are arranged. Note that the heater 18 is connected to this pressurizing chamber 14.
It may be incorporated into.

The pressure medium 15 is connected to this pressure medium supply device 16 and the pressurizing chamber 14.
The pressure medium 15 is circulated between the pressurizing chamber 14 by a pump 17, and the pressure medium 15 can be replenished, pressurized, and heated from the outside of the pressurizing chamber 14. The inside of the pressurizing chamber 14 is heated by a heater 18.
This can be done indirectly by heating the pressure medium 15 at . Furthermore, the same amount of pressure medium 15 as the river flows out of the pressurizing chamber 14 as the endless belt 13.13 runs.
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. And endless belt 13.
The impregnated base material 5 sandwiched between the impregnated base materials 5... is heated and pressurized by the pressure medium I5 press-fitted into the pressurizing chamber 14, and the impregnated resin liquid spreads uniformly, fills the voids, and hardens. and become integrated. Double belt press as pressure medium 15! Any fluid may be used as long as it exhibits fluidity under the operating conditions described in (2), but examples of these include air or nitrogen as a gas, and l as a liquid.
11 Lubricant oil, heat transfer oil, cylinder oil, etc. Waxes and low melting point polymers include polyethylene wax and paraffin, and low melting point metals include solder and wood metal.

Regardless of the type of double belt press, the existence of a large pressure distribution, especially the existence 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-entry of air in the pressure zone is likely to occur and should be avoided, for example, if the pressure distribution is less than 150% and ±5 kg/cm
″ or less is preferable.

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 resulting laminate. Usually l ky/
cm"G to 100 kg/cm"G, preferably 10kg/c11"G to 50 kg/cm"
It is G. When the pressure is lower than 1 kg/cm''G, not only is it difficult to increase the base material content, but the air evacuation effect is small, and the laminate is likely to have air bubbles mixed in.

On the other hand, a pressure higher than 100 kg7 cm''G is not only unnecessary for removing air bubbles, but also causes the base material content in the resulting laminate to become too large, causing delamination and other deterioration in strength. easy.

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, making it uneconomical;
When the temperature exceeds 00°C, problems such as internal distortion and foaming occur due to the rapid progress of curing.

When pressurizing with such a double belt press,
The resin liquid in the laminate of several base materials partially impregnated with thermosetting resin liquid per summer penetrates into the unimpregnated parts of the base materials due to the pressure applied, and the laminate is uniformly distributed in the thickness direction. It becomes impregnated. This is because a large pressure gradient occurs in the laminate in the double belt press section in the opposite direction to the direction in which the laminate travels, and this pressure gradient promotes the penetration and impregnation of the resin liquid into the unimpregnated parts of the base material. This is presumed to be because the replacement between the bubbles remaining in the base material 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 due to the pressure gradient that also occurs in the width direction of the laminate, and as a small amount of resin liquid is discharged from both ends, the air bubbles are eliminated. A laminate with no air bubbles is obtained. Since the base material is partially impregnated with the thermosetting resin liquid, the amount of resin liquid discharged from the base material laminate can be reduced even by applying pressure using a double belt press. In other words, since the base material can be partially impregnated with only the amount of resin liquid equivalent to the resin in the resulting laminate, the amount of excess resin liquid is small, and since the double belt press is vertically arranged, it can be discharged easily. The resin liquid easily flows downward, and its spread in the width direction is extremely small. If the discharge of the resin liquid is small, 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, in the laminate after passing through the pressurizing chamber 14, resin discharge portions are formed that are slightly wider in both directions than the width of the impregnated base material portion, or the ratio is as small as about 1%.

The base material arJt in the laminate thus obtained varies depending on the base material used, the type of thermosetting resin liquid, pressurizing conditions, etc., but is usually in the range of 30% by weight to 80% by weight. For example, if kraft paper is used as the base material and the side chain double bond type resin mentioned above is used as the thermosetting resin liquid, it is preferably 35 to 65 weight%, and if it is less than 35 weight%, the mechanical strength of the laminate It is undesirable because it lacks strength and bending rigidity, and when it exceeds 65% by weight, it not only tends to cause delamination, but also causes a decrease in punchability, l1ff, and l wetness, which is disadvantageous.

On the other hand, metal foil clad laminates'! i2 fabrication is carried out by overlapping a metal foil on one or both sides of the laminate of impregnated base materials at the same time as or slightly after the overlapping of the base materials, and feeding this into a double belt press. The metal foil that can be used 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 blue-tatchability, but electrolytic iron foil and aluminum foil may also be used. used.

A metal foil having a thickness of 10=100 pm is usually used.

Moreover, it is more preferable that the contact 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 substrate, it is preferable to use an adhesive. Semi-fluid, i.e. viscosity preferably 5
Adhesives having 0.000 voids or less are suitable. 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 an amine adhesive 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 the adhesive is used in a state where it is applied to metal foil, it may be precured to a semi-cured state by heat treatment at 60 to 150° C. for 2 to 7 minutes after application. The adhesive can also be applied to both layers at the same time. The thickness of the adhesive coating is IO ~
It may be about 100 μM, and 20 to 50 μM is particularly suitable.

The thickness of the laminate obtained by the present invention varies depending on the type of substrate, the composition of the thermosetting resin liquid, the use of the laminate, etc., or is usually 0.
5-3. Ou is preferred.

〔Example〕

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 00, and parts and percentages are by weight unless otherwise specified.

(Preparation of side chain double bond type resin) A separable flask (30003!) equipped with a stirrer, a thermometer with a gas introduction tube, a reflux condenser, and a dropping funnel.
12), methacrylic acid (35 g, 0.41 mol), methyl ethyl ketone (400 g), styrene monomer (80
0 g, 7.7 mol), azobisisobutyronitrile (5
, 0g) dodecyl mergabutane (12g) was charged, and polymerization was carried out at 75 to 80°C for 10 hours under a nitrogen atmosphere. Hydroquinone (0.5 g) 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-containing liquid containing a styrene-methacrylic acid copolymer having a weight average molecular weight of about 50,000 was obtained.

In addition, another reactor with the same configuration as above was installed with "Epicoat 82".
7J (trade name of epoxy resin, manufactured by Yuka Shell Epoxy Co., Ltd.) (360 g, 1 mol), methacrylic acid (138 g
, 1.6 mol), benzyldimethylamine (1.2 g)
, prepared rosebenzoquinone (0°12g), l 20
The mixture was reacted for 3 hours at C'C 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 solution to the vinylation reagent and add triphenylphosphine (
5g) and rosebenzoquinone (0.1Og) were added to rB 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 unsaturated group-containing epoxy resin is about 1
It became 5%. Heat evaporation was continued at 30-50 ml while adding styrene monomer (1000 g) intermittently. Methyl ethyl ketone detected in distillate
．． When it became less than 1%, I finished the 1M production. The thus obtained resin liquid containing the curable prepolymer has a non-volatile content of 52
It was a yellow-brown liquid with a viscosity of 6.12 poise (25°C) consisting of % by weight.

(Example and Comparative Example) Commercially available long kraft paper (weighing m 135 g/m' density 0.4
9g/cR") 100 parts by weight 1: N-Mefol melamine (Nippon Carbide Co., Ltd.!2 NiResin S-3
05) was impregnated and dried to a coating amount of 20 parts by weight, and using 8 treated substrates, the above-mentioned side chain double bond type resin liquid, unsaturated polyester resin liquid, and epoxy resin liquid to which a curing catalyst was added were predetermined. After continuous impregnation in the method and amount of
Scrap electrolytic copper foils were laminated and continuously heated at 100°C for 55 minutes using a double belt press with pressure medium storage as shown in Figure 1.
Table 1 shows the results of pressurizing and heat molding for a minute and post-curing at 120° C. for 1 hour to obtain a laminate and a single-sided copper-clad laminate. In addition, among the "impregnation methods" in Table 1, "partial impregnation (A
)" refers to the method in which the dipping method is used during impregnation, and the amount of impregnated resin is adjusted using a pair of squeezing rolls. "Partial impregnation (B)" refers to the method in which each of the eight base materials is laminated in the same manner throughout. This method uses a coating device (slit nozzle) to impregnate the entire width of the substrate with a thermosetting resin. "Complete impregnation" means that all eight substrates are completely impregnated by the dipping method. In addition, the paper width in any impregnation is 10701π.

As is clear from the results in Table 1, when the resin liquid is pressurized, the discharge m
It can be seen that a laminate with a high base material content can be obtained even though the toxicity can be suppressed to an extremely low level. In Comparative Example 1, the amount of discharged resin was excessive and the resin protruded outside the machine, but a good product was obtained. In Comparative Example 2, partial impregnation was performed, but resin impregnation 1 was insufficient for the entire base material, in Comparative Example 3, impregnation was insufficient due to insufficient pressure, and in Comparative Example 4, impregnation was insufficient due to excessive pressure. Due to lack of resin, peeling occurs and good products cannot be obtained.

〔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. an impregnation step of impregnating with a thermosetting resin liquid that does not generate
In a continuous manufacturing method for laminates that includes a heating and pressing step in which multiple sheets of impregnated base materials are piled up and heated and pressed to harden and integrate the resin liquid, the impregnation step and heating and pressing step are performed approximately vertically. In the impregnation step, the base material is partially impregnated with the resin liquid, and in the heating and pressing step, a double belt press having substantially uniform pressure over the entire area of the pressure zone is used. Since the partially impregnated resin liquid is heated and pressurized while measuring its penetration into the entire base material, the impregnated resin liquid is discharged by gravity except for a small amount of adhered material when pressurized by a double belt press. Due to this action, the laminate is flowed down and collected, so there is no problem of contamination, and it is possible to continuously produce a laminate with a high base material content and substantially no air bubbles.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing an example of a manufacturing apparatus used in the present invention. 1...Base material, 2...Immersion tank, 3...
... Resin-impregnated base material, 4... Impregnated metal base material,
5...Spacer 6...[7 fat m F
l Adjusting roll, 11...Double belt press.

Claims (5)

[Claims] (1) Essentially no drying process is required for long base materials;
In addition, there is an impregnation step in which a thermosetting resin liquid that does not substantially generate reaction by-products such as gas or liquid during the curing reaction process is applied, and a plurality of impregnated substrates are stacked and heated and pressurized to form a resin liquid. In the continuous manufacturing method of a laminate including a heating and pressing step of curing and integrating the substrates, the impregnation step and the heating and pressing step are arranged approximately perpendicularly, and in the impregnation step, the voids in each base material are The resin liquid is impregnated almost uniformly in the width direction, and in the heating and pressurizing step, the impregnation is carried out using a double belt press constituted by an endless belt that applies substantially uniform pressure over the entire pressure zone. While measuring the permeation of the resin liquid into the entire base material, the excess resin liquid is discharged out of the base material by heating and pressurizing, and is made to flow down using gravity and returned to the impregnation process. Continuous manufacturing method. (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 method for continuously manufacturing a laminate according to claim 1, which is a double belt press. (4) Pressure in heating and pressurizing process is 1 to 100 kg/cm^
2. The method for continuously manufacturing a laminate according to claim 1. (5) The method for continuously manufacturing a laminate according to claim 1, wherein the base material is paper.