KR101473522B1 - Aramid Fiber for Manufacturing Printed Circuit Board and Method for Manufacturing The Same - Google Patents

Abstract

Disclosed is an aramid fiber having a linear density of 10 denier or less and a method of producing the aramid fiber capable of realizing an aramid fabric having a thickness of 50 탆 or less. According to the method of the present invention, a plurality of monofilaments formed through a single nipping are classified into a plurality of groups, and the aramid fibers formed by the plurality of groups are wound in parallel.

Description

Technical Field [0001] The present invention relates to an aramid fiber for manufacturing a printed circuit board,

More particularly, the present invention provides aramid fibers suitable for producing aramid fabrics having a thickness of 50 탆 or less and a method for producing the aramid fibers.

It is known to use sheets made of aramid fibers as a substrate for a printed circuit board (PCB). Typically, the aramid sheet is impregnated with a resin to prepare prepregs, the laminate having low thermal expansion coefficient is manufactured using the prepregs, and the printed circuit board is manufactured using the laminate do.

Since aramid sheets can only be used for printed circuit board fabrication if they have thicknesses of 50 μm or less, almost all of the aramid sheets for printed circuit board fabrication so far studied have the nonwoven or paper form.

Despite the fact that the aramid sheet in the form of a fabric has superior strength to the aramid sheet in the form of a nonwoven or paper, the research or development of aramid fabrics for the manufacture of printed circuit boards has not been achieved until now, Because it was not possible to produce aramid fabrics.

Namely, in order for the aramid fabric to be used in the manufacture of the printed circuit board, it is required to have a thin thickness of 50 탆 or less. For the production of aramid fabrics having a thickness of 50 탆 or less, the aramid fibers used as warp and weft yarns should each have a linear density of less than 10 denier. However, according to the conventional method in which all the monofilaments formed through one spinneret form one aramid fiber, the aramid fiber has a high linear density of 200 to 3,000 denier, and the linear density of the excessively high aramid fiber An aramid fabric having a thickness of 50 mu m or less could not be produced.

Accordingly, the present invention relates to an aramid fiber and a method for producing the same, which can prevent problems due to limitations and disadvantages of the related art.

One aspect of the present invention is to provide an aramid fiber for the manufacture of a printed circuit board suitable for producing an aramid fabric having a thickness of 50 탆 or less.

Another aspect of the present invention is to provide an aramid fabric having a thickness of 50 탆 or less which can be usefully used in the manufacture of printed circuit boards.

Another aspect of the present invention is to provide a printed circuit board comprising an aramid fabric having a thickness of 50 탆 or less.

Another aspect of the present invention is to provide a method for producing aramid fibers having a linear density of 10 deniers or less.

Other features and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description. Alternatively, other features and advantages of the present invention may be understood through practice of the present invention. Objects and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims of this invention.

In accordance with one aspect of the present invention as described above, it is possible to provide a fiber reinforced thermoplastic resin composition comprising 1 to 20 aramid monofilaments and having a tenacity of 15 g / denier or more, a tensile modulus of 450 g / denier or more, and a linear density of 10 denier or less wherein the aramid fiber has a linear density.

As another aspect of the present invention there is provided a warp and weft yarn comprising warp and weft yarns each comprising from 1 to 20 aramid monofilaments and having a strength of at least 15 g / denier, a tensile modulus of at least 450 g / Or less of the total weight of the aramid fabric.

Another aspect of the invention includes an aramid fabric having warp and weft wherein each warp and weft is comprised of from 1 to 20 aramid monofilaments and has a strength of at least 15 g / denier, at least 450 g / denier A tensile modulus of elasticity, and a linear density of 10 denier or less.

As another aspect of the present invention, there is provided a method of producing an aromatic polyamide polymer, comprising the steps of: preparing an aromatic polyamide polymer; discharging a spinning dope containing the polymer through a plurality of holes formed in the spinneret; In order to achieve the above-mentioned object, there is provided a method for producing aramid fibers, comprising coagulating the discharged radiation dope, sorting the plurality of monofilaments into a plurality of groups, and winding the aramid fibers formed by the plurality of groups in parallel The present invention also provides a method for producing an aramid fiber.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are intended to provide further explanation of the invention as claimed.

According to the present invention, aramid fibers having 10 deniers or less can be produced with high productivity, and aramid fabrics having a thickness of 50 μm or less can be produced by weaving aramid fibers having 10 denier or less. The printed circuit board manufactured using the aramid fabric having a thickness of 50 탆 or less is more excellent in strength than a printed circuit board manufactured using an aramid sheet in the form of a nonwoven fabric or paper.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
FIG. 1 is a schematic view illustrating a process for producing an aramid fiber according to an embodiment of the present invention. Referring to FIG.
Figures 2-4 illustrate the bottoms of detents according to embodiments of the present invention.
5 is a cross-sectional view of an aramid fabric according to an embodiment of the present invention.

Hereinafter, embodiments of the aramid fiber for manufacturing a printed circuit board of the present invention and a method of manufacturing the same will be described in detail with reference to the accompanying drawings.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. It will be apparent to those skilled in the art that variations are possible. Therefore, the present invention encompasses all changes and modifications that come within the scope of the invention as defined in the appended claims and equivalents thereof.

The term 'aramid fiber' as used herein means a yarn composed of at least one aramid monofilament.

The method for producing an aramid fiber of the present invention comprises the steps of: producing an aromatic polyamide polymer; discharging a spinning dope containing the polymer through a plurality of holes formed in the spinneret; forming a plurality of monofilaments The method comprising the steps of: coagulating the discharged radiation dope; sorting the plurality of monofilaments into a plurality of groups; and sorting the aramid fibers formed by the plurality of groups through the classification step, .

Hereinafter, the method for producing an aramid fiber of the present invention will be described in more detail with reference to Fig. FIG. 1 is a schematic view illustrating a process for producing an aramid fiber according to an embodiment of the present invention. Referring to FIG.

The aromatic polyamide polymer can be prepared by the following method.

First, an inorganic salt is added to an organic solvent to prepare a polymerization solvent. Examples of the organic solvent include N-methyl-2-pyrrolidone (NMP), N, N'-dimethylacetamide (DMAc), hexamethylphosphoramide (HMPA) Methyl urea (TMU), N, N-dimethylformamide (DMF) or mixtures thereof may be used. The inorganic salt may be used a mixture of _{CaCl 2, LiCl, NaCl, KCl} , LiBr, KBr, or mixtures thereof. The inorganic salt is added in order to increase the polymerization degree of the aromatic polyamide. However, since the inorganic salt which is not dissolved when the inorganic salt is added in an excess amount may be present in the polymerization solvent, the content of the inorganic salt in the polymerization solvent is preferably 10% by weight or less. Since the solubility of the inorganic salt in the organic solvent is poor, water is added to completely dissolve the inorganic salt, and then the water is removed through a dehydration process, whereby a final polymerization solvent can be prepared.

Next, the aromatic diamine is dissolved in the polymerization solvent to prepare a mixed solution. The aromatic diamine may be para-phenylenediamine, 4,4'-diaminobiphenyl, 2,6-naphthalenediamine, 1,5-naphthalenediamine, or 4,4'-diaminobenzanilide.

Then, a primary polymerization is carried out by adding a predetermined amount of aromatic diacid halide to the mixed solution while stirring the mixed solution. The aromatic diacid halide may be terephthaloyl dichloride, 4,4'-benzoyl dichloride, 2,6-naphthalene dicarboxylic acid dichloride, or 1,5-naphthalene dicarboxylic acid dichloride. Through the primary polymerization, a prepolymer is formed in the polymerization solvent.

Subsequently, a secondary polymerization is carried out by further adding an aromatic diacid halide to the polymerization solvent, and an aromatic polyamide polymer is finally obtained through such secondary polymerization. The aromatic polyamide polymer may be selected from the group consisting of polyparaphenylene terephthalamide (PPD-T), poly (4,4'-benzanilide terephthalamide), poly (paraphenylene -4,4'-biphenylene-dicarboxylic acid amide), or poly (paraphenylene-2,6-naphthalene dicarboxylic acid amide).

Since the aromatic diacid halide charged in two times in the production of the aromatic polyamide polymer reacts with the aromatic diamine in a 1: 1 molar ratio, the total amount of the aromatic diacid halide to be added for the primary polymerization and the secondary polymerization, Can be determined to be the same mole as the diamine. However, when a polymerization solvent is prepared, a small amount of water may be left after the dehydration process to add water to help dissolve the inorganic salt. In this case, a small amount of water may react with the aromatic diacid halide to form an insoluble matter. Therefore, in view of the formation of such an insoluble substance, a small amount of an aromatic diacid halide may be added in a smaller amount than an aromatic diamine. On the other hand, it is preferable to adjust the amounts of the aromatic diamine and the di-cis halide so that the concentration of the aromatic polyamide polymer in the entire polymerization solution is about 5 to 20 wt% after the first and second polymerization processes are completed.

Next, an alkaline compound such as NaOH, Li ₂ CO ₃ , CaCO ₃ , LiH, CaH ₂ , LiOH, Ca (OH) ₂ , Li ₂ O, CaO or the like is added to the polymerization solution to neutralize the hydrochloric acid generated during the polymerization reaction do. On the other hand, it may be advantageous to carry out the subsequent processes by adding water to the polymerization solution obtained through the primary and secondary polymerization processes to prepare a slurry state to improve its flowability. At this time, the neutralization step and the slurry production step may be performed simultaneously by adding water in which the alkali compound is dissolved to the polymerization solution.

Subsequently, the polymerization solvent is extracted from the polymerization solution. Such an extraction process is most effective and economical to perform using water. For example, a filter may be installed in a bath equipped with an outlet, and a polymer in the form of a crum may be placed on the filter, and then water may be poured to discharge the polymerization solvent contained in the polymer together with water to the outlet. On the other hand, if the particle size of the aromatic polyamide polymer present in the polymerization solution is too large, it takes much time to extract the polymerization solvent, and the productivity may be lowered. Therefore, the pulverizing step of the aromatic polyamide polymer may be carried out before the polymerization solvent extraction step.

Then, the water remaining in the aromatic polyamide polymer is removed through dehydration and drying processes.

Next, the aromatic polyamide polymer is dissolved in a sulfuric acid solvent to prepare a spinning dope. The aromatic polyamide polymer concentration in the spinning dope is preferably 10 to 25% by weight in terms of fiber properties.

Next, as illustrated in FIG. 1, the spinning dope produced by the method described above is provided to the spinneret 20 through the spinning dope supplying section 10. The radiation dope containing an aromatic polyamide polymer is discharged through a plurality of holes formed in the detent 20. The holes may have a diameter of 0.1 mm or less. The detents 20 used in the present invention will be described in more detail below.

Subsequently, by coagulating the spinning dope discharged through the plurality of holes of the nipping 20, a plurality of monofilaments 100a respectively corresponding to the plurality of holes of the nipping 20 are obtained. Specifically, the spinning dope that descends after passing through the holes of the nail 20 passes through an air gap of a predetermined length made of air or an inert gas to form a plurality of monofilaments 100a corresponding to the respective holes Start.

Subsequently, the plurality of monofilaments 100a formed when the air gap passes through the air gap are classified into a plurality of groups. The monofilament (s) 100a contained in one group form one aramid fiber 100.

One group, i.e., one aramid fiber 100, comprises 1 to 20 monofilaments 100a. According to one embodiment of the present invention, the aramid fibers 100 comprise the same number of monofilaments (s) 100a. However, in accordance with the object of the present invention, which produces aramid fibers suitable for producing aramid fabrics having a thickness of 50 탆 or less, the aramid fibers 100 have a linear density of 10 deniers or less, the plurality of monofilaments 100a, Should be classified into an appropriate number of groups. In other words, the number of monofilaments (s) 100a included in the aramid fibers 100 should be determined so that the aramid fibers 100 have a linear density of 10 deniers or less.

Meanwhile, in the process of sorting the plurality of monofilaments 100a formed through the air gap into a plurality of groups, interference between the monofilaments 100a belonging to different groups should not occur. Further, in performing subsequent processes following the classification process of the monofilaments 100a, the subsequent processes for the plurality of aramid fibers 100 formed through the classification process must be able to be performed in parallel.

According to one embodiment of the present invention, the monofilament (s) 100a corresponding to one group and the monofilament (s) 100a corresponding to another group do not interfere with each other A plurality of holes are formed in the nest 20.

Alternatively, the nipping 20 may have a configuration in which the nipping extends in a first direction, and the plurality of holes may be arranged such that they do not overlap with each other in a second direction perpendicular to the first direction. Figures 2-4 illustrate the bottoms of detents according to these embodiments. As illustrated in FIGS. 2 to 4, a plurality of holes (not shown) of the retainer 20 may be formed on the inner surface of the retainer 20 so long as they do not overlap each other in a direction (second direction) perpendicular to the longitudinal direction H may be arranged in various manners.

After forming a plurality of aramid fibers 100 each containing one to twenty monofilaments 100a through the sorting process as described above, the aramid fibers 100 are separated from the coagulation bath 30 and the coagulation baths And finally solidified.

A coagulating solution (31) is contained in the coagulation bath (30). Since the coagulation liquid 31 is discharged through the coagulation tubes 32 together with the aramid fibers 100, the coagulation liquid 31 must be continuously supplied to the coagulation tank 30 as much as the discharged amount. A jetting unit 33 is formed in each of the coagulation tubes 32 so that the coagulating solution can be injected into the aramid fibers 100 passing through the coagulation tube 32. The jetting section 33 has a plurality of jet openings, and the coagulating liquid can be jetted to the aramid fibers 100 through the jetting ports. Preferably, the plurality of jets are aligned so that the coagulating solution can be injected radially symmetrically with respect to the aramid fibers 100. The injection angle of the coagulating liquid through the jetting section 33 is preferably 0 to 85 degrees with respect to the advancing direction of the aramid fiber 100, and in particular, an injection angle of about 30 degrees is suitable for a commercial production process.

The coagulating solution 31 is water, ethylene glycol, glycerol, alcohol, or a mixture thereof, and is maintained at -10 to + 90 ° C. Alternatively, the coagulating liquid 31 may further contain a small amount of sulfuric acid. When the aramid fiber 100 passes through the coagulating solution, the sulfuric acid present in the aramid fiber 100 is removed. The sulfuric acid is rapidly removed from the aramid fiber 100, thereby preventing the degradation of the properties of the aramid fiber 100 Sulfuric acid may be added to the coagulating liquid 31.

The fully solidified aramid fibers 100 are wound around the core tubes 70 in parallel via the neutralizing section 40, the backsheet 50, and the drying section 60.

In the neutralization unit 40, sulfuric acid remaining in the aramid fiber 100 is neutralized with an aqueous caustic solution of 0.3 to 1.3%, and the aramid fiber 100 is in the range of 0.01 to 0.1% Of a caustic aqueous solution.

Then, the content of moisture remaining in the aramid fiber 100 is adjusted in the drying section 60. The moisture content of the aramid fibers 100 can be controlled by controlling the time that the aramid fibers 100 are brought into contact with the heated drying roll or by controlling the temperature of the drying rolls.

Next, the dried aramid fibers 100 are wound on the core tubes 70, respectively. The winding speed is 300 to 1,500 m / min.

The aramid fiber 100 of the present invention produced by the above method is composed of 1 to 20 aramid monofilaments 100a and has a strength of at least 15 g / denier, a tensile modulus of at least 450 g / denier, and a denier ≪ / RTI >

According to an embodiment of the present invention, the monofilament 100a constituting the aramid fiber 100 of the present invention has a linear density of 0.5 to 2 denier.

The larger the linear density of the monofilaments 100a constituting the aramid fiber 100 is, the more the aramid fibers 100 should contain a smaller number of the monofilaments 100a. The smaller the number of the aramid fibers 100a is, the lower the impact resistance of the fabric woven with the aramid fibers 100 is weakened. Accordingly, the monofilament 100a preferably has a linear density of 2 deniers or less.

On the other hand, the aramid fibers 100 made of monofilaments 100a having a linear density of less than 0.5 denier make the weaving of the fabric itself difficult. Therefore, it is advantageous from the standpoint of ease of weaving that the aramid fiber 100 used for weaving the fabric is composed of monofilaments 100a having a linear density of 0.5 denier or more.

5 is a cross-sectional view of an aramid fabric 200 woven using the aramid fibers 100 of the present invention.

As illustrated in FIG. 5, the aramid fibers 100 of the present invention having a strength of at least 15 g / denier, a tensile modulus of at least 450 g / denier, and a linear density of less than or equal to 10 deniers may be applied to warp 110 and weft 120 The aramid fabric 200 produced by performing the plain weaving has a thickness T of 50 탆 or less and can therefore satisfy the thickness requirements of the aramid sheet for the manufacture of printed circuit boards.

The aramid fabric 200 of the present invention can be used in the manufacture of printed circuit boards through conventional methods. That is, the aramid fabric 200 is impregnated with a resin to prepare a prepreg, a laminate having a low thermal expansion coefficient is manufactured using the prepreg, and a printed circuit board is manufactured using the laminate do.

The printed circuit board made using the aramid fabric 200 of the present invention has higher tensile strength and uniform tensile properties under the same areal density as printed circuit boards made using nonwoven or paper-type aramid sheets.

10: Radiation Dope Supply Section 20: Detention
30: Coagulation tank 40: Neutralization unit
50: Number detail 60: Dry part
70: winding section 100: aramid fiber
110: warp 120: weft
200: Aramid fabric

Claims (11)

delete delete delete delete An aramid fabric having warp and weft,
Wherein the warp and weft yarns are aramid fibers comprised of from 1 to 20 aramid monofilaments each having a linear density of from 0.5 to 2 denier, each yarn having a strength of at least 15 g / denier, a tensile modulus of at least 450 g / denier, Lt; / RTI &
Wherein the aramid fabric has a thickness of less than or equal to 50 microns. delete Producing an aramid fiber;
Preparing an aramid fabric having a thickness of 50 탆 or less by using the aramid fiber as warp and weft;
Impregnating the aramid fabric with a resin to prepare a prepreg;
Preparing laminates with the prepreg; And
Forming a printed circuit board using the laminate,
The step of producing the aramid fiber comprises:
Preparing a polyparaphenylene terephthalamide polymer;
Discharging a spinning dope comprising the polymer through a plurality of holes formed in the spinneret;
Coagulating said discharged radiation doping to obtain a plurality of monofilaments respectively corresponding to said plurality of holes;
Classifying the plurality of monofilaments into a plurality of groups; And
And winding the aramid fibers formed by the plurality of groups in parallel through the classification step,
Each of the monofilaments has a linear density of 0.5 to 2 denier,
Wherein the plurality of monofilaments are classified into the plurality of groups such that each of the aramid fibers is composed of 1 to 20 monofilaments and has a linear density of 10 deniers or less. delete delete 8. The method of claim 7,
Wherein the holes are formed in the detachment in such a manner that the monofilaments corresponding to any one of the groups and the monofilaments corresponding to the other group do not interfere with each other. 11. The method of claim 10,
The detaching has a form extending in a first direction,
Wherein the plurality of holes are arranged so as not to overlap each other in a second direction perpendicular to the first direction.

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