JP2002212893A - Aromatic polyamide fiber paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new aromatic polyamide fiber paper having excellent heat resistance and electrical insulating properties in high humidity, especially suitable as a substrate for a laminate for an electric circuit, reducing an impure ion amount and water absorption as the problems of a conventional polyamide fiber paper, especially characteristics related to reliability, eliminating defective electrical insulating properties in high humidity, improving adhesiveness to electric/electronic parts. SOLUTION: This aromatic polyamide fiber paper comprises 40-97 wt.% based on the total weight of paper of an aromatic polyamide short fiber and 3-60 wt.% based on the total weight of an aromatic polyamide pulp as main components. The aromatic polyamide pulp comprises a wet aromatic polyamide pulp which is obtained by providing an aromatic polyamide dope with a shear force by a beating action and coagulating the dope with a precipitant. The aromatic polyamide short fiber and/or the aromatic polyamide pulp is heat- treated in an organic solvent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an aromatic polyamide fiber paper, and more particularly, to a laminate for an electric circuit board which is excellent in heat resistance and electrical insulation resistance under high humidity. Polyamide fiber paper used for this purpose.

[0002]

2. Description of the Related Art Heat-resistant, heat-resistant dimensional stability, moisture-resistant dimensional stability, electrical insulation, and deformation resistance (such as twisting, warping, and waving are unlikely to occur) in substrates used for laminates for electric circuit boards. That is, various properties such as light weight and further reduction in the amount of impurity ions and water absorption related to reliability are required.
Aromatic polyamide fiber paper is superior to paper base made of other materials in heat resistance, electrical insulation, heat resistance dimensional stability, light weight, etc. It is being used for base materials.

[0003] For example, polymetaphenylene isophthalamide staple fiber ("Cornex" manufactured by Teijin Limited) and polymetaphenylene isophthalamide pulp (fibrid)
Paper consisting of: "electrically insulating paper" (JP-A-2-236907)
JP-A-4-6708, etc.), polyparaphenylene terephthalamide staple ("Kevlar" manufactured by DuPont) and copolyparaphenylene-3,4'-oxydiphenylene terephthalamide staple (Teijin) Aromatic polyamide fiber paper comprising "Technola" manufactured by Co., Ltd.) and an organic resin binder; "Resin-impregnated sheet" (JP-A-1-92233) and "Method for producing aromatic polyamide fiber paper" (JP-A-Heisei 2). No. 47392).

[0004] However, although the former two fiber papers are excellent in heat resistance, when heat-treated at a high temperature of 250 ° C or more, they not only shrink and cause dimensional changes, but also have an equilibrium moisture content (water content) of the fiber. Since it is high and has a high impurity ion content, it is inferior in electrical insulation, especially when it is kept under high humidity for a long time, so it should be used for electrical insulation base materials that require high reliability. Can not.

[0005] On the other hand, the latter fiber paper is superior to the former in terms of the equilibrium moisture content of the fiber and the content of impurity ions, but also uses an organic resin as a binder component. Impurity ion content and water absorption are high, and it is difficult to use as a base material for electrical insulation which requires a high degree of reliability.

Furthermore, instead of using an organic resin as a binder component, a meta-type aromatic polyamide fibrid was used to fibrillate with a para-type aromatic polyamide short fiber (eg, “Kevlar” manufactured by DuPont). "High-density para-aramid paper" (Japanese Patent Application Laid-Open No. 61-160500) has been proposed in which fiber paper is bonded with micro fibers of para-type aromatic polyamide (for example, "Kevlar" manufactured by DuPont).

This paper has excellent properties such as heat resistance, heat-resistant dimensional stability, moisture-resistant dimensional stability, and deformation resistance (it is unlikely to cause twisting, warping, waving, etc.), but has an organic resin binder. In the production method of the meta-type aromatic polyamide fibrids to be used instead, the equilibrium moisture content and the content of impurity ions are also high, and there is a problem in electrical insulation especially under high humidity, and this improvement is strongly desired. .

[0008]

DISCLOSURE OF THE INVENTION The present invention is excellent in heat resistance and electric insulation under high humidity, and is particularly suitable as a base material for laminates for electric circuits. In particular, as a characteristic relating to reliability, the amount of impurity ions and the water absorption are reduced, the problem of poor electrical insulation under high humidity is eliminated, and the adhesion to electric / electronic parts is improved. An object of the present invention is to provide an aromatic polyamide fiber paper.

[0009]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems of the prior art, and as a result, have a low impurity ion content, a small equilibrium moisture content, and Wet fragrance that has been subjected to shearing force by beating action to an aromatic polyamide dope, is coagulated by a precipitant, and is heat-treated in an organic solvent to para-type aromatic polyamide staple fiber, which is also excellent in heat resistance and heat resistance dimensional stability. When producing aromatic polyamide fiber paper in which aromatic polyamide pulp is mixed and uniformly dispersed as a binder component, the uneven distribution of the binder component is eliminated, the uniformity of the paper is improved, and the obtained laminate for an electric circuit board is subjected to high temperature and high humidity. The dimensional stability of the product is improved, the amount of deformation in the manufacturing process is reduced, and the adhesion to electrical and electronic components is improved, and the electrical insulation performance under high humidity is satisfactory. To investigate to be, in which led to the present invention.

Thus, according to the present invention, 40 to 97% by weight of aromatic polyamide staple fiber based on the total weight of paper and 3 to 60% by weight of aromatic polyamide pulp based on the total weight of paper are the main components. Aromatic polyamide fiber paper, and
The aromatic polyamide pulp is composed of a wet aromatic polyamide pulp obtained by applying a shearing force to an aromatic polyamide dope by beating action and coagulating the dope with a precipitant, and the aromatic polyamide staple fiber and / or the aromatic polyamide pulp are obtained. An aromatic polyamide fiber paper is provided, wherein the aromatic polyamide pulp is heat-treated in an organic solvent.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The aromatic polyamide fiber paper in the present invention includes a paper-like material, a nonwoven fabric, or a sheet-like material containing aromatic polyamide staple fiber and wet aromatic polyamide pulp. As the polyamide pulp, pulp obtained by applying a shearing force to an aromatic polyamide dope by beating action and coagulating the dope with a precipitant is used.

In the polyamide used for doping the aromatic polyamide short fiber or the aromatic polyamide, 80 mol% or more, preferably 90 mol% or more of the repeating units constituting the polyamide are represented by the following formula (1). It consists of the aromatic homopolyamide or aromatic copolyamide represented.

[0014]

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Here, Ar ₁ and Ar ₂ represent aromatic groups, and among them, the same or the same selected from the following formula (2):
Different aromatic groups are preferred. However, the hydrogen atom of the aromatic group may be substituted with a halogen atom, a lower alkyl group, a phenyl group, or the like.

[0016]

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The production method and fiber properties of such an aromatic polyamide are described, for example, in British Patent No. 150194.
8, U.S. Pat. No. 3,733,964, U.S. Pat.
No. 7756, No. 3868929, Japanese Patent Application Laid-Open No. 49-100322, Japanese Patent Publication No. 47-10.
No. 863, JP-A-58-144152, JP-A-4-65513 and the like.

Such aromatic polyamides include those made of meta-type aromatic polyamide and those made of para-type aromatic polyamide. In the present invention, para-type aromatic polyamide is preferably used. The short fibers and dopes made of such para-type aromatic polyamide are those made of the above-mentioned aromatic polyamide, in which the chain bonds are coaxial or parallel and oriented in the opposite direction. 80 of the above Ar ₁ and Ar ₂
An aromatic group (A) whose mole% or more is represented by the following formula (3)
And / or an aromatic polyamide (B) is used. In particular, a copolyparaphenylene-3,4'-oxydiphenylene terephthalamide dope is optimally used as a dope for preparing a wet aromatic polyamide pulp used in the present invention.

[0019]

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Specific examples of the aromatic polyamide staple fiber include polyparaphenylene terephthalamide staple fiber ("Kevlar" manufactured by DuPont), copolyparaphenylene / 3,4'-oxydiphenylene terephthalate. Examples include amide short fibers ("Technola" manufactured by Teijin Limited) and the like. In particular, the latter has a low content of impurity ions due to the solvent used in the fiber production process, that is, a small amount of electric insulation. It is more preferable because it is excellent.

Further, copolyparaphenylene / 3,4'-oxydiphenylene / terephthalamide short fiber is used as the aromatic polyamide short fiber, and a solid cation-converting and non-ion-adsorbing material is formed on the surface thereof. In the case where the inorganic compound is fixed, the impregnating property of the compounded varnish is improved, so that the amount of deformation in the manufacturing process of the laminate for electric circuit boards is reduced, and the electrical insulation of the obtained laminate under high humidity is reduced. This is a more preferred embodiment because the properties and dimensional stability are further improved.

The cation-converting and non-ion-adsorbing inorganic compound is a compound capable of exchanging cations and also adsorbing non-ions. Specific examples thereof include silica / alumina. , Silica magnesia, kaolin, acid clay, activated clay, talc, bentonite, osmos and the like. These compounds are particularly preferably fixed to the fiber surface as solid particles, since the adhesion reinforcing effect is further improved. The size (particle diameter) of the particles is about 0.01 to 5 μm. In order to fix the inorganic compound on the fiber surface in this manner, for example, the inorganic compound particles may be pressed against the fiber surface in a state where the fiber surface is softened and bite into the fiber surface.

The single fiber fineness of the aromatic polyamide short fibers is usually preferably in the range of 0.11 to 11.1 dtex, and more preferably 0.33 to 1.1 dtex.
Those having a range of 5.56 dtex are preferable. When the single fiber fineness is less than 0.11 dtex, there are many difficulties in the yarn production technology, and it is not only difficult to stably produce fibers of good quality due to yarn breakage and fluffing, but also cost is low. It is not preferable because it becomes high. On the other hand, the single fiber fineness is 11.1 d
If the tex exceeds tex, the mechanical properties of the fiber, especially the strength, are greatly reduced, and the fiber is not practical. In addition, the aromatic polyamide short fibers may be partially fibrillated mechanically, but if the ratio is too large, the effect of the present invention such as impregnation of the compounded varnish is reduced and the effect of the present invention cannot be obtained. It is preferable to reduce the ratio as much as possible.

Further, the fiber length of the aromatic polyamide short fibers is preferably in the range of 0.5 to 80 mm, more preferably in the range of 1 to 60 mm, and particularly, paper is formed by a wet method. If you do, 2-12m
A range of m is optimal. If the fiber length is less than 0.5 mm, the mechanical properties of the resulting aromatic polyamide fiber paper (fiber aggregate) tend to be insufficient, while if the fiber length exceeds 80 mm, short fibers are opened. Properties, dispersibility, etc. deteriorate, the uniformity of the obtained fiber aggregate is impaired,
Again, the mechanical properties tend to be insufficient, which is not preferable.

Next, as the aromatic polyamide pulp, a wet aromatic polyamide pulp obtained by applying a shearing force to the dope of the aromatic polyamide by beating action and coagulating it with a precipitant is used. For example, a copolyparaphenylene-3,4′-oxydiphenylene terephthalamide dope is optimally used.

The above copolyparaphenylene-3,4'-
Oxydiphenylene terephthalamide dope is copolyparaphenylene-3,4'-oxydiphenylene.
It is a solution composition (dope) in which terephthalamide is dissolved in a solvent system, and as a solvent, N-methyl-2-pyrrolidone (hereinafter, referred to as NMP) or a mixed solvent mainly composed of N-methyl-2-pyrrolidone is used. It is preferably used as a solvent system mixed with calcium chloride.

As a preferred example of such a method for preparing an aromatic polyamide solution composition, a predetermined amount of pellets or pulverized fine powder of the aromatic polyamide, a predetermined amount of NMP and a predetermined amount of calcium chloride are prepared. 30 ℃ in a container
It is prepared by dissolving the polymer (aromatic polyamide) with stirring at a temperature not lower than the boiling point, preferably at a temperature of about 40 to 80 ° C., for about 20 minutes to 2 hours.

Of course, a uniform solution composition containing such an aromatic polyamide or NMP, calcium chloride (NMP / CaCl ₂ ), and an adhesion-improving resin may be further added, if necessary, with, for example, a stabilizer and a flame retardant. And additives such as a release agent, a colorant, a matting agent, an antistatic agent, and a filler.

The wet aromatic polyamide pulp used in the present invention can be obtained, for example, by dropping the above-mentioned aromatic polyamide solution composition into a precipitant (coagulation bath liquid) containing water as a main component. As such a precipitant, in addition to the use of water alone, other precipitants can be used by mixing with water. Further, upon dropping the aromatic polyamide solution composition, by stirring the precipitant at high speed,
At the same time, the aromatic polyamide is coagulated by desolvation from the dropped and introduced solution composition to coagulate the aromatic polyamide, and at the same time, is precipitated by operating to give a shearing force by beating action. Can be obtained.

The wet aromatic polyamide pulp is mainly composed of the aforementioned copolyparaphenylene-3,4'-
A pulp composed of oxydiphenylene terephthalamide is preferably used, but a pulp composed of polymetaphenylene isophthalamide may be mixed and used as necessary. However, in order to keep the water absorption low, the mixing ratio of the pulp composed of the polymetaphenylene isophthalamide is preferably as small as possible,
50 of the total weight of the wet aromatic polyamide pulp used
What is used is less than 40% by weight, preferably less than 40% by weight.

In the present invention, the above-mentioned aromatic polyamide short fibers and / or the aromatic polyamide pulp are heat-treated in an organic solvent. The temperature at this time is 30 ° C or more and 130 ° C
Is preferably less than 40 ° C. and less than 120 ° C. The heat treatment time is suitably from 5 to 60 minutes.

The organic solvent used for the heat treatment is NM
P, dimethylformamide (hereinafter, referred to as DMF), dimethylacetamide (hereinafter, referred to as DMAC), or dimethylsulfoxide (hereinafter, referred to as DMSO) may be used as long as it swells the above-mentioned aromatic polyamide short fibers and aromatic polyamide pulp.

When the thus obtained aromatic polyamide short fibers and aromatic polyamide pulp are mixed, the mixing ratio is such that the amount of the aromatic polyamide short fibers in the total solid weight of the paper is 40 to 97% by weight. %, The amount of the aromatic polyamide pulp needs to be in the range of 3 to 60% by weight, and the amount of the aromatic polyamide staple fiber is in the range of 70 to 97% by weight. Preferably, the amount of the aromatic polyamide pulp is in the range of 3 to 30% by weight.

When the amount of the aromatic polyamide pulp is less than 3% by weight, the aromatic polyamide pulp cannot exhibit the binder performance when the aromatic polyamide fiber paper is made, making the paper making impossible. When the amount of the aromatic polyamide pulp exceeds 60% by weight, the space between the aromatic polyamide short fibers is filled with the aromatic polyamide pulp,
Moreover, since these are in close contact with each other and adhere to each other, the density of the paper is increased. Particularly, when the paper is used as a base material for an electric insulating material in a state where the resin is impregnated with a resin such as a compound varnish, the resin is used. It is not evenly and sufficiently impregnated into the inside of the paper, causing partial unevenness or insufficient impregnation inside the paper. As a result, poor electrical insulation characteristics and insulation breakdown under high temperature and high humidity are likely to occur. , And in close contact with the aromatic polyamide pulp,
Despite the adhesion, there are problems such as low delamination strength. In order to avoid these problems, particularly the problems in the state of impregnating a resin such as a compounded varnish, it is preferable that the amount of the aromatic polyamide pulp be as small as possible. A range of 30% by weight is more preferred.

Furthermore, the aromatic polyamide fiber paper of the present invention has properties of heat resistance dimensional stability and deformation resistance (phenomena such as twisting, warping, and waving) when used as a base material for an electrically insulated circuit board laminate. However, it is easily affected by values such as bulk density, tensile strength and delamination strength of the aromatic polyamide fiber paper. Therefore, those having physical properties in the following ranges are preferably exemplified.

That is, the aromatic polyamide fiber paper of the present invention has a bulk density of 0.45 to 0.80 g / cm ³ , preferably 0.55 to 0.70 g / cm ^3. The aromatic polyamide fiber paper has a tensile strength of 14.7 N / 15 mm or more, preferably 19.6 N / 15 mm or more.
68.6 N / 15 mm is preferable, and
The delamination strength is at least 0.098 N / 15 mm, preferably at least 0.147 N / 15 mm.

When the bulk density is less than 0.45 g / cm ³ , or when the delamination strength is less than 0.098 N / 15 mm, the adhesive strength between short fibers in the middle layer of the paper decreases. Because the amount of impregnating varnish inside the paper is likely to increase, the prepreg manufacturing process and the manufacturing process of laminates for electric circuit boards, especially the partial movement of short fibers corresponding to the flow of impregnating varnish in the laminating press process, This tends to cause fiber density unevenness inside the obtained laminate for an electric circuit board. As a result, the heat resistance dimensional stability and the deformation resistance may be reduced.

On the other hand, when the tensile strength of the aromatic polyamide fiber paper is less than 14.7 N / 15 mm, the paper is easily cut in the impregnation step of the compounded varnish, and the bulk density is 0.80 g / cm ^3. When the amount exceeds, the impregnating property of the compounded varnish into the paper is apt to decrease, and the resulting electrical circuit board laminate will deteriorate in properties such as electrical insulation, heat-resistant dimensional stability, and deformation resistance, which is not preferable. .

[0039] Such an aromatic polyamide fiber paper can be produced by a known method (step). For example, para-type aromatic polyamide short fibers and aromatic polyamide pulp heat-treated in an organic solvent by the above-described method are weighed so as to have a predetermined ratio, and the fiber concentration is about 0.
If necessary, a dispersing agent or a viscosity modifier is added to an aqueous slurry that has been uniformly dispersed and adjusted by adding it to water so as to have a concentration of 15 to 0.40% by weight. A wet paper web is formed by a wet paper making method using a paper machine, and the obtained wet paper is dried to obtain a desired thickness by heating and pressing.
It can be obtained as an aromatic polyamide fiber paper having bulk density, strength, peel strength and the like. Alternatively, para-type aromatic polyamide short fibers and aromatic polyamide pulp heat-treated in an organic solvent according to the method described above are randomly laminated on a belt while being opened with a high-speed fluid, and then heated and pressed and dried. To obtain a desired aromatic polyamide fiber paper.

As described above, when the aromatic polyamide fiber paper produced by these methods is used as a base material of a laminate of an electric circuit board, the resulting laminate has dimensional stability against heat and deformation. Properties such as properties (twisting, warping, waving, etc.) tend to be affected by properties such as bulk density, tensile strength and delamination strength of aromatic polyamide fiber paper. For this reason, it is preferable to adjust and control the papermaking conditions so that these characteristics fall within the above-mentioned ranges, and to carry out drying and heating / pressing.

In particular, the conditions of the heating and pressing are important. For example, when heating and pressing using a calender, one hard surface roll having a diameter of about 15 to 80 cm and a diameter of about 30 to 80 cm are used. It may be carried out between an elastic roll having a surface deformation of 100 cm and preferably between two hard surface rolls having a diameter of about 20 to 80 cm. That is, when the heating and pressing conditions are less than the above conditions, the paper strength after processing is likely to be lower than 14.7 N / 15 mm,
Further, the delamination strength tends to be less than 0.098 N / 15 mm, and the bulk density tends to be less than 0.45 g / cm ³ . Further, in the manufacturing process of the laminate for an electric circuit board, there is a process of performing a high-temperature heat treatment at 240 ° C. or more. It is more preferable because the thermal dimensional change of paper and the induction of internal distortion are suppressed, and the heat resistance dimensional stability and deformation resistance of the obtained laminate are improved. According to the study of the present inventors, the temperature: 2
Optimally, calendering is performed in the range of 80 to 360 ° C and a linear pressure of 1764 to 3920 N / cm. The aromatic polyamide fiber paper produced under these conditions is, for example, 280.
The thermal dimensional change rate after 5 minutes at 5 ° C. is as small as 0.25% or less, and the thermal dimensional stability is excellent, and the bulkiness is also 0.45 to 0.45%.
Within the range of 0.80 g / cm ³ , tensile strength and delamination strength higher than the above-mentioned performance can be obtained. If the heating and pressurizing conditions are performed at 360 ° C. and exceeding 3920 N / cm, the bulk density of the obtained paper tends to increase beyond 0.8 g / cm ^3, which is not preferable.

[0042]

According to the present invention, an aromatic polyamide fiber paper comprising an aromatic polyamide staple fiber and a wet aromatic polyamide pulp can be obtained. However, unlike the conventional paper, an aromatic polyamide fiber paper is used instead of the organic resin binder. Since aromatic polyamide pulp is used, the amount of impurity ions and the water absorption can be significantly reduced.

An aromatic polyamide fiber paper using an aromatic polyamide pulp in place of the organic resin binder generally has a problem of low adhesiveness for binding short fibers. It was necessary to use the amount of polyamide pulp.

However, when the amount of the aromatic polyamide pulp is increased, when the resin is used as a base material for an electric insulating material used in a state of being impregnated with a resin such as a compounded varnish, the resin is evenly spread inside the paper. In addition, the impregnated resin is not sufficiently impregnated, causing partial unevenness and insufficient impregnation inside, and causing various problems. Therefore, in the paper used for such an application, the use ratio of the aromatic polyamide pulp is as small as possible. Less is preferred.

In the present invention, as the aromatic polyamide pulp, a wet pulp obtained by applying a shearing force to the dope of the aromatic polyamide by beating action and coagulating it with a precipitant is used. // Since the wet polyamide pulp is heat-treated in an organic solvent, it is possible to reduce the use ratio of the aromatic polyamide pulp necessary for forming the aromatic polyamide paper, and to achieve long-term reliability of electric / electronic parts. The performance is also improved. For this reason, even when the aromatic polyamide paper according to the present invention is used for applications such as a substrate for an electrical insulating material as described above, it is excellent in heat resistance and electrical insulation under high humidity,
In particular, it is suitably used as a substrate of a laminate for electric circuits, and can reduce the amount of impurity ions and the water absorption, and can solve the problem of poor electrical insulation under high humidity.

[0046]

The present invention will be described in more detail with reference to the following examples. In addition, the measurement value of each evaluation item in an Example was calculated | required according to the following measurement method.

(1) Bulk density: Measured in accordance with JIS C-2111 6.1.

(2) Tensile strength: Measured by a method according to JIS C-2111-7 using a constant-speed elongation type tensile tester.

(3) Delamination strength: The strength (N / 15 mm) when the intermediate layer portion of a sample having a length of 200 mm and a width of 15 mm was peeled in a T-shape was measured using a constant-speed extension type tensile tester. .

(4) Thermal dimensional change rate: 250 m in length using a high-precision two-dimensional coordinate measuring machine (manufactured by Mutou Kogyo Co., Ltd.)
m, for the length direction of the sample having a width of 50 mm, the length before the heat treatment and the length after the heat treatment at 280 ° C. for 5 minutes were measured,
The thermal dimensional change rate was calculated by the following formula.

[0051]

(Equation 1)

(5) Electrical insulation characteristics (BDV): JIS-
It measured by the method based on 18.1 of C2111.

(6) Extraction of Impurity Ions: 2 g of fibers are cut into small portions in 50 ml of distilled water, and then charged and heat-treated in an autoclave to extract impure ions. With respect to the extracted water, the amount of each impurity ion was measured by ICP analysis and ion chromatography, and the amount of impurity ion per liter of extracted water was calculated.

(7) Equilibrium moisture content The equilibrium moisture content of the aromatic polyamide fiber paper is determined according to JIS L-
According to 1013, the sample was dried in an atmosphere of 120 ° C., and then dried at a temperature of 20 ° C. and a relative humidity of 65% RH.
The time is adjusted, the moisture content in the sample is determined, and the ratio to the weight of the sample in the absolutely dry state is calculated, which is expressed as a percentage (%).

When the sample contains staple fibers or pulp composed of two or more aromatic polyamides, the equilibrium moisture content of each component is measured independently and expressed as a weight average according to the mixing ratio.

(8) Deformation Amount of Laminated Plate High-purity brominated bisphenol A type epoxy resin and orthocresol novolak type epoxy resin have dicyandiamide as a curing agent and 2-ethyl- as a curing accelerator.
After impregnating aromatic polyamide fiber paper with a compounded varnish obtained by dissolving an epoxy resin composition containing 4 methylimidazole in a mixed solution of methyl ethyl ketone and methyl cellosolve, the solution is heated at a temperature of 110 to 120 ° C for 5 to 5 minutes. After drying for 10 minutes, a B-stage prepreg paper having a resin content of 55% by volume was prepared. 18μ of the prepreg paper
Laminated on both sides of the copper foil of thickness, and further laminated the same copper foil on the outside, 170 ° C under reduced pressure by hot pressing
Pressing was performed at 40 kg / cm × 50 minutes to cure the resin, thereby obtaining a laminate for an electric circuit board, and further subjected to a post-curing treatment at a temperature of 200 ° C. for about 20 minutes in a hot-air dryer.

This laminate for an electric circuit board is cut into a 150 mm square, and a copper foil on both sides is left in a frame shape with a width of 20 mm from an end of the laminate, and a 110 mm square equivalent portion at the center is entirely etched. The copper foil is removed to prepare a sample for evaluation.

After the partially etched laminate for an electric circuit board is heat-treated at a temperature of 260 ° C. for 10 minutes, the maximum deformation amount (warpage amount or uplift amount due to twisting or waving) starting from the central portion is determined. Measure and define the amount of deformation.

Example 1 Aromatic polyamide short fiber was composed of copolyparaphenylene / 3,4'-oxydiphenylene terephthalamide, and 0.5% by weight of talc and 0.1% of osmos on the fiber surface. Single fiber fineness fixed by weight: 1.67 dtex, fiber length (cut length): 3
mm short fiber (“Technola” manufactured by Teijin Limited): 93% by weight, as a wet aromatic polyamide pulp, a dope composed of copolyparaphenylene / 3,4′-oxydiphenylene / terephthalamide, and polymetaphenylene A shear force is applied to the mixed dope obtained by mixing the isophthalamide dope with the beating action as described above, and the mixture is coagulated with a precipitant. -101 ") was dispersed in a pulper using a wet aromatic polyamide pulp obtained by heat-treating in DMSO at 80 ° C. for 30 minutes: 7% by weight, and dispersed to a concentration of 0.03%. Agent (“YM-80” manufactured by Matsumoto Yushi Co., Ltd.)
Short fiber dispersion slurry for papermaking was prepared. Next, papermaking was performed using a slurry for papermaking using a tappy-type square papermaking machine to obtain an aromatic polyamide paper.

Further, the aromatic polyamide fiber paper was heated at a temperature of 230 ° C. and a linear pressure of 156 using a calender comprising a pair of hard surface metal rolls having a diameter of about 400 mm.
After heating and pressurizing under the condition of 8 N / cm, further, the diameter:
Using a calender comprising a pair of hard surface metal rolls of about 500 mm, temperature: 320 ° C., linear pressure: 1960 N /
Heating and pressurizing under the condition of cm, an aromatic polyamide fiber paper having a basis weight of 72 g / m ² was obtained.

Table 1 shows the characteristic values of the obtained fiber paper measured and evaluated by the above-mentioned measuring methods. Further, a prepreg paper was prepared by impregnating the compounded varnish using the fiber paper according to the method described above, and the amount of deformation of the laminate for electric circuit boards prepared using the prepreg paper was measured. The results are shown in Table 1.

[Comparative Example 1] As aromatic polyamide short fibers, short fibers composed of copolyparaphenylene / 3,4'-oxydiphenylene terephthalamide similar to those used in Example 1: 77% by weight (fragrance) The total weight of the group III polyamide short fibers is 83.7% by weight) and polymetaphenylene isophthalamide, and the draw ratio in the fiber production process is 1.4 times, and the single fiber fineness is 3.3 dt.
ex, a short fiber having a fiber length of 6 mm: 15% by weight (a ratio of the total weight of aromatic polyamide short fibers to 16.3% by weight) was disintegrated and dispersed in water by a pulper. A dispersant (“YM-80” manufactured by Matsumoto Yushi Co., Ltd.) was added to the fiber so as to obtain a fiber concentration of 0.1%.
A 2% by weight short fiber dispersion slurry for papermaking was prepared.

Next, paper was made using a tapping-type square paper machine using the papermaking slurry, and bisphenol A was added thereto.
Epichlorohydrin-type water-dispersible epoxy resin (Dick Fine EN-027 manufactured by Dainippon Ink and Chemicals, Inc.)
0 "), and then dried and cured for about 20 minutes in a hot air drier at a temperature of 160 ° C. to reduce the aromatic polyamide short fiber content to 92% by weight.
Thus, an aromatic polyamide paper having an epoxy resin binder adhered to 8% by weight was obtained.

Next, this aromatic polyamide fiber paper is
Using a calendering machine consisting of a pair of hard surface metal rolls having a diameter of about 400 mm, temperature: 230 ° C., linear pressure: 15
After heating and pressurizing under the condition of 68 N / cm, the polymetaphenylene isophthalamide short fiber is further softened and partially melted to exhibit the function as an adhesive. Using a calender made of rolls, temperature: 320 ° C, linear pressure: 1960
By heating and pressurizing under the condition of N / cm, an aromatic polyamide fiber paper having a basis weight of 72 g / m ² was obtained.

With respect to the obtained fiber paper, each characteristic value measured and evaluated by the above-mentioned measuring method is also shown in Table 1. Further, a prepreg paper was prepared by impregnating the compounded varnish using the fiber paper according to the method described above, and the amount of deformation of the laminate for electric circuit boards prepared using the prepreg paper was measured. The results are shown in Table 1.

[Comparative Example 2] Aromatic polyamide short fiber was composed of copolyparaphenylene / 3,4'-oxydiphenylene terephthalamide, and 0.5% by weight of talc and 0.1% of osmos on the fiber surface. Single fiber fineness fixed by weight: 1.67 dtex, fiber length (cut length): 3
mm short fiber (“Technola” manufactured by Teijin Limited): 93% by weight, as a wet aromatic polyamide pulp, a dope composed of copolyparaphenylene / 3,4′-oxydiphenylene / terephthalamide, and polymetaphenylene Using 7% by weight of wet polyamide pulp prepared by a mixed dope mixed with an isophthalamide dope, the mixture is dispersed by a pulper and a dispersant ("YM-80" manufactured by Matsumoto Yushi Co., Ltd.) is adjusted to 0.03% concentration. ") To prepare a slurry for dispersing short fibers for papermaking.

Next, papermaking was performed using a tapping-type square papermaking machine using the papermaking slurry to obtain an aromatic polyamide fiber paper.

Next, this aromatic polyamide fiber paper was heated and pressed in the same manner as in Example 1 to obtain an aromatic polyamide fiber paper.

With respect to the obtained fiber paper, each characteristic value measured and evaluated by the above-mentioned measuring method is also shown in Table 1. Further, a prepreg paper was prepared by impregnating the compounded varnish using the fiber paper according to the method described above, and the amount of deformation of the laminate for electric circuit boards prepared using the prepreg paper was measured. The results are shown in Table 1.

[0070]

[Table 1]

[0071]

As described above, according to the present invention, there are problems in the aromatic polyamide fiber paper conventionally used as the base material of the laminate for electric circuit boards, particularly, the surface direction and the thickness with respect to changes in temperature and humidity. The dimensional change in the vertical direction and the electrical insulation are remarkably improved, and the adhesiveness of electric / electronic parts can be remarkably improved.

Therefore, in the electric circuit board laminate using the aromatic polyamide fiber paper of the present invention as a base material, twisting, warping, waving, and the like hardly occur in the production process and application, so that the design of a fine circuit is not required. An innovative material that can maintain high reliability over a long period of time even when electronic components with low temperature and humidity expansion coefficients such as leadless ceramic chip carrier (LCCC) and bare chips are directly soldered and mounted. In particular, it is a suitable substrate for a laminate for an electric circuit board in applications requiring a high degree of lightness, a high degree of heat-resistant dimensional stability, and electrical insulation.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Torukei Matsui 3-4-1, Amihara, Ibaraki-shi, Osaka Teijin Limited Osaka Research Center F-term (reference) 4L055 AF35 BB30 EA32 FA13 FA16 FA18 FA19 GA01 GA33

Claims (5)

[Claims] 1. An aromatic polyamide staple fiber of 40 to 97% by weight, based on the total weight of the paper, and 3 to 60%, based on the total weight of the paper.
An aromatic polyamide fiber paper mainly containing an aromatic polyamide pulp of about 10% by weight, wherein the aromatic polyamide pulp gives a shearing force to an aromatic polyamide dope by beating action and is coagulated by a precipitant. An aromatic polyamide fiber paper comprising the obtained wet aromatic polyamide pulp, wherein the aromatic polyamide short fiber and / or the aromatic polyamide pulp are heat-treated in an organic solvent. 2. The aroma according to claim 1, wherein the amount of the aromatic polyamide staple fiber is 70 to 97% by weight based on the total weight of the paper, and the amount of the aromatic polyamide pulp is 3 to 30% by weight based on the total weight of the paper. Polyamide fiber paper. 3. The aromatic polyamide fiber paper according to claim 1, wherein the aromatic polyamide short fiber is a short fiber made of polyparaphenylene terephthalamide. 4. The aromatic polyamide fiber paper according to claim 1, wherein the aromatic polyamide short fibers are short fibers composed of copolyparaphenylene / 3,4′-oxydiphenylene terephthalamide. 5. The pulp according to claim 1, wherein the wet aromatic polyamide pulp is mainly composed of copolyparaphenylene / 3,4′-oxydiphenylene terephthalamide.
5. The aromatic polyamide fiber paper according to any one of items 4 to 5.