JP7045305B2 - Manufacturing method of monofilament for screen gauze - Google Patents

Description

The present invention relates to a method for manufacturing a monofilament for screen gauze.

As the screen gauze for printing, a gauze woven material made of polyester or polyamide is often used at present from the viewpoint of strength, dimensional stability and the like (see, for example, Patent Documents 1 and 2). In particular, polyester gauze fabric is widely used because it has excellent dimensional stability and is suitable for printing in fields where high precision printing is required.
In recent years, the degree of integration has increased in the printing field for electronic devices such as printed distribution frames. Therefore, it is required to improve the printing accuracy of the screen gauze. In recent years, labor costs and processing costs have been increasing, so it is also required to reduce the production cost of screen gauze.

It is necessary to prevent halation in order to improve printing accuracy and precision printing. Preferable examples of the method for this are (1) a method of forming a fiber (original monofilament) kneaded with a colorant so as not to transmit light of a specific wavelength, and (2) a method of dyeing after weaving. However, the latter requires a dyeing process, which increases the production cost, makes it difficult to dye a monofilament with a fineness of about 5 to 30 dtex in a dark color, and reduces the strength of the monofilament due to the thermal history of the dyeing process. As a result, there are problems such as a decrease in printing durability and a decrease in the performance of the screen gauze.
Under these circumstances, there is a demand for a high-quality, fine-grained monofilament with excellent print durability, which is excellent in productivity and can be used without halation without dyeing.

As the original monofilament, for example, in Patent Document 1, in a monofilament for screen sheath in which a composite form forms a core-sheath structure, both the core-sheath components are made of polyester, and the sheath component is anthraquinone yellow, which is an organic pigment. A core-sheath composite monofilament for a screen sheath has been proposed, which includes, has a reflectance of 5.0% or less for light having a wavelength of 300 to 500 nm, and has an initial elastic modulus of 100 to 125 cN / dtex.
In Patent Document 2, the intrinsic viscosities of the core component and the sheath component are specified, and the sheath component is a solid-phase polymerized polyethylene terephthalate containing 0.2 to 0.4% by weight of metal fine particles, and the modulus at an elongation of 5% is 20. ~ 40%, elongation at break 20-40%, free shrinkage of the innermost layer measured from the day after product winding to 10 days is 0.3% or less, 100,000 meters in the filament longitudinal direction, and 10 μm or more thicker than the fiber diameter. A core-sheath type polyester monofilament having one or less knots has been proposed, and it is described that an organic pigment may be added to the sheath component.

Japanese Patent No. 4661501 International Publication WO2007 / 013270

However, it is difficult for the monofilament for screen screens, which is described in Patent Document 1 and Patent Document 2 to have polyester in the core and polyester containing an organic pigment in the sheath, to contain the organic pigment in a high concentration, and a high halation suppressing effect can be obtained. do not have. When the sheath contains a high concentration of organic pigment, the organic pigment becomes a foreign substance to the molecular chain of polyester, and the filament is easily worn in the yarn making process and the weaving process, and a large amount of scum is used in the yarn path of the yarn making process and the reed of the weaving process. As a monofilament and as a screen gauze, good quality cannot be obtained.
Further, the monofilament for screen gauze containing these organic pigments has a problem that pan sinking is likely to occur when the modulus (strength of about 5 to 10% in elongation) is high by 5 to 10%.

Therefore, the present invention solves the above-mentioned problems, has excellent process passability in processes such as spinning and drawing, reduces scum and pan sink marks, has a high halation suppressing effect, and has high quality with good printing durability. It is an object of the present invention to provide a method for manufacturing a monofilament for a strong uncoated screen gauze.

The present invention is a method for producing a monofilament for a high-strength raw-bonded screen, which is spun at a specific spinning speed using a specific raw material masterbatch and a diluted resin, and is subjected to a specific relaxing treatment in a drawing step to be glossed. By containing a specific amount of defoamer and defoaming agent, although it has a high halation suppressing effect, there is no thread breakage or knot in the spinning or drawing process, scum and pan sink marks are reduced, and printing durability is improved. It has been found that it is possible to manufacture a monofilament capable of obtaining a screen gauze having excellent quality.
That is, the present invention first contains 0.1 to 1% by mass of a matting agent, 0.3 to 1.2% by mass of an adhesive, a breaking strength of 5.6 to 8 cN / dtex, and breaking elongation. In the method for producing a raw polyethylene terephthalate monofilament for screen gauze having a degree of 20 to 40%, the intrinsic viscosity (IV) is 0.5 to 0.75 dl / g, and the concentration of the raw material is 2 to 12% by mass. Using the adhering master batch and the diluted resin having an intrinsic viscosity (IV) of 0.6 to 1 dl / g, the concentration of the adhering agent was 0.3 to 1 with respect to the adhering agent master batch and the diluted resin. The first step of adjusting the resin to 2% by mass, melt-extruding, and melt-spinning at a spinning speed of 1200 to 1800 m / min to obtain an undrawn yarn, after drawing the obtained undrawn yarn. The gist thereof is a method for producing a monofilament for screen gauze, which comprises a second step of imparting relaxation with a relaxation rate of 2 to 6%.
Secondly, in the above-mentioned manufacturing method, the gist of the monofilament is a method for manufacturing a monofilament for screen gauze, which is a fiber in which the dyeing agent is dispersed over the entire cross section of the fiber.
Third, the combination of the masterbatch of the original coating agent and the diluted resin is adjusted as the core resin, and the copolymerized polyester having a relative viscosity of 0.6 to 0.7 dl / g is used as the sheath resin, and the core resin and the sheath are used. The first step of melt-extruding each of the partial resins and melt-spinning at a spinning speed of 1200 to 1800 m / min to obtain undrawn yarn, and after drawing the obtained undrawn yarn, the relaxation rate is 2 to 6%. The gist thereof is a method for producing a monofilament for screen gauze, which includes a second step of imparting relaxation.

According to the production method of the present invention, using a specific masterbatch of a dyeing agent and a diluted resin, melt spinning, stretching / relaxing under specific spinning conditions, and controlling the concentration of the matting agent / dyeing agent, etc. By manufacturing the high-strength monofilament, it has high process passability in the spinning and drawing processes, reduces scum and pan-sink, suppresses halation, and has good printing durability. A monofilament can be obtained.

Hereinafter, the present invention will be described in detail.
The present invention is a method for producing a raw polyethylene terephthalate monofilament for screen gauze.

In the method for producing a monofilament for screen gauze of the present invention, a masterbatch of a primer and a diluted resin are used.
The primer masterbatch in the present invention is polyethylene terephthalate (PET) containing a primer. In the present invention, it is preferable to use unmodified polyethylene terephthalate in which the third component is not copolymerized as the PET of the masterbatch of the primer.
A masterbatch of a primer can usually be produced by kneading a primer and PET.
The intrinsic viscosity (IV) of PET used in the masterbatch of the primer is 0.65 to 1.1 dl / g, preferably 0.7 to 1 dl / g. When the intrinsic viscosity (IV) is less than 0.65 dl / g, the IV of the masterbatch is less than 0.5 dl / g, the spinnability of the monofilament is poor, and the strength of the monofilament tends to be low. If the IV exceeds 1.1, a load may be generated on the screw during kneading, and a normal masterbatch of the depositing agent may not be produced.

The primer masterbatch in the present invention contains a primer. The base material preferably has an average reflectance of 15% or less, more preferably 10% or less, and particularly preferably 8% or less, with respect to light having a wavelength of 300 to 500 nm. That is, when the photosensitive resin is cured with ultraviolet rays in the plate making process, light having a wavelength in this range is often reflected, and it is preferable to suppress the reflection having a wavelength in this range in order to prevent halation. When the average reflectance in this wavelength range is in the above range, the light is less likely to cause halation on the surface of the warp or weft during screen printing, so that the exposure-unnecessary portion is not exposed and cured, and precision printing can be performed. It will be possible.

The dyeing agent is not particularly limited as long as it has a light absorption property having a wavelength of 300 to 500 nm, but for example, talc, chromate, ferrocyanide, various metal sulfates, sulfides, and selenium. Inorganic pigments such as compounds and phosphates, phthalocyanine-based, quinacridone-based, isoindolinone-based, perinone-based, dioxazine-based organic pigments, benzeneazo-based (monoazo, disazo, etc.), heterocyclic azo-based (thiazole azo, benzothiazole). Azo, quinoline azo, pyridine azo, imidazole azo, thiophena azo, etc.), anthraquinone-based, condensation-based (quinophthaline, styryl, coumarin, etc.) indigoid dye, triphenylmethane dye, xanthene dye, alizarin dye, acrydin dye, cyanine dye, etc. Alternatively, carbon black, a colored filler in which a pigment or a dye is dispersed in fine particles formed of an organic compound, or the like can be mentioned. These may be used alone or in combination of two or more.

As the dyeing agent, organic pigments and dyes are preferable from the viewpoint of suppressing thread breakage and scum, and reed scraping, and organic dyes are most suitable from the viewpoint of uniform dispersibility in monofilament.

When the adhering agent is a powder or particles, the number average particle size is preferably 0.01 μm to 10 μm, more preferably 0.05 μm to 2 μm. Within this range, thread spots tend to be less likely to occur. That is, if the particles are too large, it becomes difficult to disperse them uniformly, so that the strength of the yarn is lowered and yarn spots are likely to occur. Further, from the viewpoint of polyester spinning operability, it is preferable to use a disperse dye that is sparingly soluble in water.

Typical disperse dyes include Dianix series dyes manufactured by Dyster, Sumikaron series dyes manufactured by Sumika Chemtech, Kayalon Polyester series dyes and Kayalone Microester series dyes manufactured by Nippon Kayaku Co., Ltd., Kayaset series dyes, and Mitsui BASF. Miketon series dyes and Palanil series dyes, TD series dyes manufactured by Daito Chemix, Kiwaron Polyester series dyes manufactured by Kiwa Chemical Industry Co., Ltd., Terrasil series dyes manufactured by Ciba Specialty Chemicals, Fouron series dyes manufactured by Clariant, and Mitsubishi Chemical Co., Ltd. Dyerain series and the like are suitable. These disperse dyes can also be used alone or in combination.

As a suitable commercially available dye, examples of the yellow dye include Diaresin Yellow H2G manufactured by Mitsubishi Chemical Corporation and Nylosan Yellow N-5GL manufactured by Clariant. Further, as the red dye, Dianix Red AC-E manufactured by Distar Co., Ltd. can be mentioned, and as the blue dye, Dianix Blue AC-E manufactured by Distar Co., Ltd. can be mentioned.
Further, yellow pigments and orange pigments are preferable from the viewpoints of being able to color the undiluted solution as uniformly as possible and allowing the monofilament to pass through so as not to be scraped in the process of processing, convenience, and cost. Of these, the anthraquinone system shown in Color Index Y193, Chemical Substance No. (5) -1259 of the Chemical Substances Control Law is preferable.

In the production method of the present invention, a masterbatch of a raw material and a diluted resin are adjusted, melt-extruded into a spinneret or the like, and melt-spun.
The content of the primer (concentration of the primer) in the masterbatch of the primer is preferably 2 to 12% by mass. If it is less than 2% by mass, the appropriate melt viscosity in melt spinning tends not to be maintained, and the ratio of the diluted resin tends to be low at the time of dilution, and the cost tends to be high. If it exceeds 12% by mass, the moisturizing agent is not uniformly mixed at the time of melting, which causes color spots and streaks on the mesh and tends to deteriorate the quality.

The defoaming agent masterbatch may be one to which a matting agent or the like is added in addition to the defoaming agent.

The content of the matting agent (matting agent concentration) in the masterbatch of the moisturizing agent is preferably 12% by mass or less from the viewpoints of halation suppressing effect, scraping prevention effect such as reed scraping, and uniform dispersibility.

The matting agent in the present invention suppresses the transmission and reflection of light and suppresses the glare of fibers, and examples thereof include inorganic particles such as titanium oxide, zinc oxide, and calcium carbonate. Titanium oxide is preferable from the viewpoint of cost and ultraviolet absorption. In the case of titanium oxide, the anatase type is preferable, and the primary particle size thereof is preferably 0.1 to 0.8 μm.

The IV of the primer masterbatch in the present invention is 0.5 to 0.75 dl / g, more preferably 0.6 to 0.7 dl / g. If the IV is less than 0.5 dl / g, the spinnability of the monofilament tends to decrease or the strength of the monofilament tends to decrease.
If the IV exceeds 0.75 dl / g, a solid-phase polymerized PET resin with an IV of 1.1 dl / g or more will be used during the production of the masterbatch, and a load will be applied to the screw during kneading, resulting in a normal master. It is difficult to produce a batch, and the obtained masterbatch tends to have the undiluted agent not uniformly dispersed, viscosity drops are likely to occur, and the physical properties of the masterbatch tend to be unstable. Further, even if a monofilament is manufactured by using this masterbatch of the moisturizing agent, the obtained monofilament has problems such as dispersion spots of the moisturizing agent.

When producing a masterbatch of a raw material, a masterbatch having a low viscosity is first produced, and then solid-phase polymerization is performed so that IV is in the range of 0.5 to 0.75 dl / g. May be good.

As the diluting resin for diluting the masterbatch of the raw material in the present invention, unmodified polyethylene terephthalate is preferable. This diluted resin may be one that has undergone solid phase polymerization or may be one that has not undergone solid phase polymerization. The IV of the diluted resin is preferably 0.6 to 1 dl / g, more preferably 0.8 to 0.95 dl / g. If the IV is less than 0.6 dl / g, the strength of the obtained monofilament will be low, and the obtained screen gauze will have inferior printing durability. When the IV exceeds 1 dl / g, the viscosity drops easily, the physical properties of the obtained monofilament are not stable, and the depositing agent is unevenly dispersed, and the spinning operability, stretching operability, etc. are passed through the process during silk reeling. The sex gets worse.

The diluted resin in the present invention may contain a matting agent. The content of the matting agent in the diluted resin is preferably 1.2% by mass or less from the viewpoints of halation suppressing effect, scraping prevention effect such as reed scraping, and uniform dispersibility.

In the production method of the present invention, a masterbatch of a raw material and a diluted resin are used to adjust the concentration of the raw material and melt-extruded into a spinneret or the like.
When adjusting the masterbatch of the raw material and the diluted resin, the concentration of the raw material after dilution is adjusted to 0.3 to 1.2% by mass. More preferably, it is 0.5 to 1.0% by mass. If it is less than 0.3% by mass, the UV photosensitive resin does not solidify and tends to cause a halation problem. If it exceeds 1.2% by mass, scum, reed scraping, etc. will occur, and the quality of the monofilament will be impaired.

The mixing ratio (mass ratio) of the masterbatch of the raw material and the diluted resin in the present invention is preferably 1: 5 to 1:15. More preferably, it is 1: 8 to 1:12. When the mass ratio of the masterbatch of the primer is larger than 1: 5, the primer is uniformly dispersed, but the amount of the masterbatch added is large, so that the viscosity drop is large and the obtained monofilament is insufficient in strength. Therefore, the printing durability tends to be poor, and the production cost tends to be high. When the mass ratio of the masterbatch of the masterbatch is smaller than 1:15, it is difficult for the masterbatch to be uniformly dispersed, and spots and streaks are generated when the mesh fabric is used, and the quality tends to be poor.

In the present invention, the difference between the intrinsic viscosity of the diluted resin and the intrinsic viscosity of the original adhesive masterbatch shown below is that the intrinsic viscosity is easily uniformly dispersed, and the physical properties of the obtained monofilament are stabilized to obtain a mesh fabric. It is preferably −0.1 to 0.45 dl / g, and more preferably 0.1 to 0.4 dl / g, from the viewpoint that it is easy to prevent streaks from appearing on the surface.
[Number 1]
Difference in intrinsic viscosity = (IV of diluted resin)-(IV of primer masterbatch)

The monofilament in the present invention may be a single component and a fully dispersed single yarn using only the above-mentioned masterbatch and diluted resin, or the above-mentioned masterbatch and diluted resin may be used only for the core component. It may be a core-sheath composite fiber.
A particularly preferred embodiment is a single yarn in which the dyeing agent is dispersed throughout the fiber and the single component is fully dispersed.

In the present invention, a suitable sheath resin for producing a core-sheath composite fiber using the above-mentioned masterbatch of the dyeing agent and the diluted resin as the core resin will be described.
The sheath resin constituting the sheath component in the present invention is preferably a copolymerized polyester. As the copolymerized polyester, specifically, modified polyethylene terephthalate obtained by copolymerizing polyethylene glycol is preferable. The molecular weight of polyethylene glycol in the case of copolymerization is more preferably in the range of 300 to 6000, and more preferably in the range of 400 to 1000. When the molecular weight is less than 300, the boiling point of polyethylene glycol is low, so that polyethylene glycol is scattered outside the reaction system during the polycondensation reaction of polyester, and it tends to be difficult to obtain a certain amount of copolymerization. When the molecular weight of polyethylene glycol exceeds 6000, the oxidative decomposition resistance of the copolymerized polyester tends to deteriorate, and it tends to be difficult for polyethylene glycol to uniformly copolymerize.
In the copolymerized polyester obtained by copolymerizing polyethylene glycol in the present invention, the copolymerization amount of polyethylene glycol is preferably 1 to 12% by mass, more preferably 2 to 10% by weight, based on the polyester. 1% or more is preferable from the viewpoint of suppressing the generation of scum and maintaining good adhesion to the photosensitive resin. From the viewpoint of maintaining good tension and waist of the screen gauze, 12% by mass or less is preferable.
The glass transition temperature of the copolymerized polyester is preferably 45 to 68 ° C., and it is preferable to appropriately adjust the molecular weight and the copolymerization amount of polyethylene glycol within such a range. When the glass transition temperature is 45 ° C. or higher, the glass transition point is usually higher than room temperature by a certain level or more, so that the dimensional stability of the screen gauze tends to be good. When the glass transition temperature is 68 ° C. or lower, it is preferable from the viewpoint of reducing scum and maintaining good adhesion to the photosensitive resin.
Further, as other copolymerization components, a dioxy compound such as hexamethylene glycol, adipic acid, isophthalic acid, sulfoisophthalic acid, dicarboxylic acid such as phthalic acid, bisphenol A and the like may be copolymerized. From the viewpoint that the effect of the above can be easily obtained, it is particularly preferable that the polyethylene glycol is substantially copolymerized with the above-mentioned polyethylene glycol.

The intrinsic viscosity (IV) of the copolymerized polyester constituting the sheath resin in the present invention is preferably 0.6 to 0.7 dl / g, more preferably, from the viewpoint of easy acquisition of strength and good spinnability. It is 0.62 to 0.68 dl / g.

The concentration of the matting agent of the copolymerized polyester constituting the sheath resin in the present invention is preferably 0.2 to 0.6% by mass. When the concentration of the matting agent is less than 0.2% by mass, halation is likely to occur when the resin is exposed to light in screen printing, and when it exceeds 0.6% by mass, the traveler is scraped or weaved when the undrawn yarn is drawn. Reeds of time are likely to be scraped.

In the production of the monofilament of the present invention, as an additive, an antistatic agent, an antistatic agent, a light resistant agent, etc. are added as long as the spinning and stretching operability, weaving property, etc. are not hindered, as long as the effects of the present invention are not impaired. You may.

According to the present invention, the above-mentioned masterbatch of the raw material and the diluted resin are prepared and melt-extruded, melt-spun, stretched, and relaxed to produce a screen gauze monofilament. At this time, as a spinning method, it can be appropriately produced by a method such as a direct drawing method or a conventional method.

In the melt-spinning step of the monofilament for screen gauze of the present invention, the diluted resin and the masterbatch of the dyeing agent are mixed and adjusted, melt-eluted, supplied to the spinneret, and melt-spun. The masterbatch of the undiluted agent and the diluted resin may be mixed by dry blending using a mixer such as an auto blender. Chips mixed by a mixer may be melt-extruded using a single-screw or twin-screw extruder, supplied to a spinneret, and melt-spun.
Hereinafter, examples of suitable embodiments of melt spinning will be shown.
For example, the molten polymer is weighed by a gear pump and extruded from a nozzle in a spinning head kept at 290 to 300 ° C., the yarn is slowly cooled while keeping warm at 290 to 340 ° C., cooled with quench air, and an oil agent is used. After adjusting the adhesion amount to 0.15 to 0.3% by mass, a monofilament for screen insulation can be obtained on the undrawn yarn bobbin at a specific spinning speed.
In the present invention, the spinning speed is 1200 to 1800 m / min, preferably 1400 to 1700 m / min. When the spinning speed is less than 1200 m / min, the molecular orientation of the undrawn yarn becomes low and the draw ratio becomes large, so that the deformation speed and the amount of deformation at the time of drawing become large, so that yarn breakage is likely to occur and knots are likely to occur. .. When the spinning speed exceeds 1800 m / min, the molecular orientation of the undrawn yarn becomes high, so that the orientation at the time of drawing becomes small, the strength of the monofilament decreases, and the mesh has low printing durability.

In the drawing step of the monofilament for screen gauze of the present invention, it is preferable to introduce a relaxing step for the purpose of sufficiently crystallization, fixing the fiber structure, reducing the heat shrinkage rate of the drawn yarn, and suppressing pan sink marks. The relaxation rate in the relaxation step is preferably 2 to 6% for the purpose of easily reducing reed scraping, scum generation, and pan sink marks. A more preferred range of relaxation rates is 3-5%. When the relaxation rate is less than 2%, the tension between the rollers in the stretching step becomes high, so that the orientation of the amorphous portion becomes high, and reed scraping tends to occur frequently. In addition, during weaving, panning may occur and streaks tend to occur. If the relaxation rate exceeds 6%, the orientation of the amorphous portion is excessively lowered, so that the quality of the yarn is deteriorated due to the generation of tarmi of the yarn during drawing, or the yarn is too loose during drawing and cannot be drawn. In addition, the 5% modulus and the 10% modulus are significantly reduced, resulting in a screen gauze with poor dimensional stability. Therefore, in the present invention, when the relaxation rate is outside the above range, it is difficult to obtain a high-quality monofilament whose breaking strength and breaking elongation are within the range of the present invention.
In the stretching step, it is preferable to carry out a stretching ratio of 1.01 to 1.05 for the purpose of eliminating deflection, and then perform main stretching. In this stretching, it is preferable to preheat the temperature of the roll heater to 80 to 88 ° C. for stretching. After that, it is preferable to perform heat setting with a plate heater at the same time as the relaxing step. The heater temperature of the plate heater in the relaxing step is preferably about 120 to 230 ° C.

The monofilament for screen gauze obtained by the production method of the present invention will be described below.

The content of the moisturizing agent for the monofilament for screen gauze in the present invention is preferably 0.3 to 1.2% by mass from the viewpoint of scum, reed scraping, and quality. More preferably, it is 0.5 to 1.0% by mass.

The content of the matting agent of the monofilament for screen gauze in the present invention is preferably 0.1 to 1% by mass from the viewpoint of scum, reed scraping, and quality. More preferably, it is 0.3 to 0.8% by mass.

When the monofilament for screen gauze in the present invention is a core-sheath composite fiber, the content of the matting agent of the core component is preferably 0 to 0.7% by mass, more preferably 0.02 to 0.5% by mass. be.
The content of the matting agent in the sheath component is preferably 0.2 to 0.6% by mass, more preferably 0.3 to 0.5% by mass.

The ratio (area ratio) of the core component and the sheath component of the monofilament for screen gauze in the present invention, that is, the core-sheath ratio is a core component: from the viewpoint of maintaining good filament strength and resistance to wear due to reeds during weaving. The sheath component (core-sheath ratio) is preferably 45:55 to 90:10, and particularly preferably 55:45 to 80:20. When the sheath component exceeds 55%, it is difficult to maintain the breaking strength and the breaking elongation, and the printing durability of the screen gauze tends to decrease. When the sheath component is less than 10%, peeling of the core sheath occurs, thread breakage, weaving, monofilament scraping due to reeds, misalignment, and adhesion to the photosensitive resin during screen printing. Tends to decline.

The fiber cross-sectional shape of the monofilament for screen gauze in the present invention is not particularly limited, but the outer shape of the fiber is preferably circular. Further, it is preferable that the core component is not exposed to the surface layer of the filament. From the viewpoint of the dimensional stability of the screen after the gauze, the shape and arrangement of the core component are preferably arranged concentrically with the sheath component to form a round fiber cross section.

The fineness of the monofilament for screen gauze in the present invention is preferably 4 to 30 dtex. From the viewpoint of providing high-precision precision printing, 6 to 18 dtex is more preferable.

The breaking strength of the monofilament for screen gauze in the present invention is 5.6 to 8 cN / dtex, more preferably 5.8 to 7.5 cN / dtex, from the viewpoint of the gauze property and print durability of the screen gauze. .. When the strength is less than 5.6 cN / dtex, the print durability tends to decrease. If the strength exceeds 8 cN / dtex, the elongation must be less than 20%. In this case, reed scraping, scum, and fibrillation occur during weaving, and the weaving property and the gauze property of the screen gauze are deteriorated. May be damaged.

The breaking elongation of the monofilament for screen gauze in the present invention is 20 to 40%. More preferably, it is 23 to 32%. When the breaking elongation of the monofilament for screen gauze of the present invention is less than 20%, reeds are scraped during weaving, scum is generated, and weaving property and gauze property are deteriorated. When the elongation at break exceeds 40%, the dimensional stability of the screen gauze tends to deteriorate due to the increase in the amorphous portion of the filament, and the printing durability is lowered.

Hereinafter, the present invention will be described in detail with reference to examples. The present invention is not limited to the examples described below. The physical characteristics and evaluation of the filament in the examples were as follows.
A. Intrinsic viscosity (IV)
Using a Ubbelohde type viscosity tube, the sample was dissolved in a mixed solvent of phenol: tetrachloroethane = 6: 4 and a dissolution time of 80 ° C. × 1 hour, and measured at a measurement temperature of 20 ° C. to obtain an intrinsic viscosity (IV). rice field.
B. Breaking strength and breaking elongation According to JIS-L-1013, measurement is performed using an AGS-1KNG autograph tensile tester manufactured by Shimadzu Corporation under the conditions of a sample yarn length of 20 cm and a constant velocity tensile speed of 20 cm / min. The value obtained by dividing the maximum value of the load on the load-elongation curve by the fineness was defined as the breaking strength (cN / dtex), and the elongation rate at that time was defined as the breaking elongation (%).
C. Spinning operability The spinning operability was evaluated based on the presence or absence of yarn trimming during spinning, the occurrence of scum on guides, and color spots. If the process passability is good and there is no scum or color spots, "○", if the process passability is slightly poor and there is no scum or color spots, "△", color spots or process passability If it is bad or if a scum occurs, it is marked as "x".
The color spots were visually determined by the unstretched bobbin, and the scum visually confirmed the presence or absence of the accumulation of the guide.
D. Extension operability
Stretching operability was evaluated by installing slits to prevent yarn breakage and knot outflow during stretching. "○" was given when there was no thread breakage and knots, "Δ" was given when there was no knots but there was thread breakage and knots, and there was no thread breakage, and "×" was given when there was thread breakage and knots. A slit having a slit width of +10 μm in diameter of the monofila after stretching was installed, and 1 kg of winding was collected to evaluate the presence or absence of yarn breakage and knots.
E. Weaving property evaluation
The weavability was evaluated for yarn breakage during warping, yarn breakage during weaving, and scum generation. If there is no thread breakage during warping and there is no thread breakage or scum during weaving, "○", if there is no thread breakage during warping, if there is thread breakage or scum during weaving, or if there is thread breakage during warping, weaving When there was no thread breakage and no scum occurred, it was marked as "△", and when there was thread breakage during warping and there was thread breakage or scum during weaving, it was marked as "x".
F. Evaluation of halation A printing plate was prepared by applying a diazo resin type photosensitive resin to a screen gauze with a film thickness of 10 to 11 μm, appropriately exposing the screen, and washing with water. The presence or absence of halation at this time was observed, and when no halation was observed, it was marked as "○", when it was delicate whether or not halation was occurring, it was marked as "△", and when halation was clearly generated, it was marked as "x".
G. Evaluation of Printing Durability of Screen Gauze Using the obtained monofilament for screen gauze, a woven fabric for screen gauze of 300 mesh / 2.54 cm was woven to obtain a screen gauze. A screen plate was made using the obtained screen gauze, and the printing pattern at the time of printing 1000 sheets and the damage of the screen gauze were observed. If the print pattern is not distorted or damaged, it is marked with "○", if it is distorted or slightly damaged, it is marked with "x", and if it cannot be determined whether or not it is distorted or damaged, it is marked with "△".
H. Comprehensive evaluation Regarding the five items of spinning operability, stretching operability, weaving operability, halation evaluation, and screen gauze printing durability evaluation, all of them are evaluated as 〇, and those with one or more minor defects. Is Δ, and if even one item has ×, it is regarded as ×.

[Example 1]
1 each of the masterbatch masterbatch (anthraquinone yellow 7.5% by mass polyethylene terephthalate, titanium oxide: 4% by mass, IV: 0.53 dl / g) and the diluted resin (polyethylene terephthalate, IV: 0.85 dl / g). The polymer was dry-blended at 9 (mass ratio), melted in a uniaxial extruder, and extruded under the conditions of a spinning cylinder (using a heat insulating cylinder) at 300 ° C. and an orifice φ0.37 of the spinning nozzle. The yarn is slowly cooled and cooled with quench air, adjusted to 0.25% by mass of oil, and then undrawn yarn bobbin at a spinning speed of 1540 m / min (concentration of original material: 0.75% by mass, oxidation). Titanium: 0.40% by mass, difference in intrinsic viscosity between diluted resin and master batch: 0.32 dl / g) was obtained. The obtained unstretched monofilament was stretched at a stretching speed of 800 m / min and a roll heater temperature of 85 ° C., and while heat was set at a plate heater temperature of 132 ° C., relaxation treatment was performed at a relaxation rate of 4% to obtain an 8 dtex screen gauze monofilament. Obtained.

[Example 2]
An 8 dtex monofilament for a screen cloth was obtained in the same manner as in Example 1 except that the IV of the resin of the masterbatch of the dyeing agent was 0.68 dl / g.

[Example 3]
An 8 dtex monofilament for an adhesive screen was obtained in the same manner as in Example 2 except that the concentration of the adhesive in the masterbatch was 10% by mass.

[Comparative Example 1]
Example 1 except that the IV of the depository master batch was 0.51 dl / g, the titanium oxide concentration was 0% by mass, the IV of the diluted resin was 0.63 dl / g, and the titanium oxide concentration was 0.4% by mass. Similarly, a monofilament for 8 dtex original screen gauze was obtained.

[Comparative Example 2]
An 8 dtex monofilament for an uncoated screen was obtained in the same manner as in Example 1 except that the IV of the diluted resin was 1.1 dl / g and the spinning speed was 1450 m / min in the spinning step.

[Comparative Example 3]
An 8 dtex monofilament for a screen cloth was obtained in the same manner as in Comparative Example 1 except that the IV of the masterbatch of the masterbatch was 0.8 dl / g.

[Comparative Example 4]
Except for the case where the mass ratio of the masterbatch of the dyeing agent and the diluted resin was 1:14, the concentration of the depositing agent of the masterbatch of the dyeing agent was 15% by mass, and the concentration of titanium oxide was 12% by mass, the same as in Example 2. Similarly, a monofilament for 8 dtex original screen gauze was obtained.

[Comparative Example 5]
An 8 dtex monofilament for an adhesive screen was obtained in the same manner as in Example 2 except that the titanium oxide concentration of the masterbatch was 0% by mass and the titanium oxide concentration of the entire monofilament was 0% by mass.

[Comparative Example 6]
Examples except that the mass ratio of the original masterbatch to the diluted resin was 1:24, the concentration of the original masterbatch was 5% by mass, and the concentration of the original was 0.2% by mass in the entire monofilament. In the same manner as in No. 1, a monofilament for 8 dtex original screen gauze was obtained.

[Comparative Example 7]
Same as in Example 1 except that the titanium oxide concentration of the masterbatch of the original adhesive was 20% by mass, the concentration of titanium oxide in the entire monofilament was 2% by mass, and the concentration of the adhesive in the entire monofilament was 1.2% by mass. A monofilament for 8 dtex original screen gauze was obtained.

[Comparative Examples 8 and 9]
An 8 dtex monofilament for an uncoated screen was obtained in the same manner as in Example 1 except that the stretch ratio was changed in the stretching step to set the elongations to 15% and 50%.

[Comparative Example 10]
The IV of the original depositor master batch is 0.49 dl / g, the concentration of titanium oxide is 0% by mass, the concentration of the adhesive is 10% by mass, the IV of the diluted resin is 0.56 dl / g, and the concentration of titanium oxide in the entire fiber is set. In the same manner as in Example 1, 8 dtex monofilaments for the original screen gauze were obtained except that the content was 0.4% by mass.

[Comparative Example 11]
Using only the masterbatch of the primer (concentration of the primer: 1% by mass, IV: 0.68 dl / g, titanium oxide concentration: 4% by mass), melt with a uniaxial extruder and spin in the spinning process. An 8 dtex monofilament for a ground screen was obtained in the same manner as in Example 1 except that the speed was set to 1650 m / min.

[Comparative Example 12, Example 4, Comparative Example 13]
An 8 dtex monofilament for screen gauze was obtained in the same manner as in Example 2 except that the relaxation rates were set to 0%, 2%, and 8%.

[Comparative Examples 14 and 15]
An 8 dtex monofilament for an uncoated screen was obtained in the same manner as in Example 2 except that the spinning speed was set to 800 m / min and 2500 m / min.

[Example 5]
The same as the base resin as the master batch and the diluted resin of Comparative Example 1 were used for the core resin, and 0.4% by mass of titanium oxide was contained, and polyethylene glycol (PEG: # 400, 4.8% by mass / polymer) was co-existed. Polymerized copolymer polyethylene terephthalate (IV: 0.65 dl / g, glass transition temperature: 66 ° C.) is used as the sheath resin, the core-sheath ratio (area ratio) is 2: 1, and the orifice diameter is set according to a conventionally known spinning method. An undrawn monofilament was obtained by spinning at a spinning temperature of 300 ° C. and a winding speed of 1610 m / min using a spinning cap having a diameter of 0.37 mm. The obtained unstretched monofilament was stretched at a stretching speed of 800 m / min and a roll heater temperature of 85 ° C., and while heat was set at a plate heater temperature of 132 ° C., relaxation treatment was performed at a relaxation rate of 4% to obtain an 8 dtex screen gauze monofilament. Obtained.

[Example 6]
The same masterbatch and diluted resin as in Example 1 were used for the core resin, and a monofilament for an 8dtex screen was obtained in the same manner as in Example 5 except that the spinning speed was changed to 1540 m / min. ..

[Comparative Example 16]
An 8 dtex monofilament for screen gauze was obtained in the same manner as in Example 6 except that the core-sheath ratio was changed to 3: 7.

Table 1 shows the production conditions, yarn characteristics, and the results of each evaluation of the monofilaments of Examples 1 to 6 and Comparative Examples 1 to 16.

The monofilaments for the dyeing screens obtained from Examples 1 to 6 control the viscosity of the dyeing agent master match, the concentration of the dyeing agent, the viscosity of the titanium oxide and the viscosity of the diluted resin, and the concentration of titanium oxide, respectively, and further master. The viscosity of the batch and the diluted resin was also controlled, melt extrusion was performed, and the spinning speed and the relaxation rate at the time of drawing were controlled within the range of the present invention. The yarn quality was good with no spots, knots, scum, or scraping. Further, the screen woven fabric obtained from these screen woven monofilaments had no scum during weaving and was of good quality. Further, the screen gauze had good dimensional stability, no scum, good adhesiveness to the photosensitive resin, no halation, and high quality in printing durability. Further, among these, in Examples 2, 3, 5 and the like, screen gauze having good fiber physical characteristics, no scum, halation, reed shaving, and thread spots, and particularly excellent printing durability was obtained.
The screen gauze using the monofilament for screen gauze obtained from Comparative Example 1 in which the strength of the monofilament is low has inferior printing durability.
The monofilament for the uncoated screen gauze obtained from Comparative Example 2 using a diluted resin having an IV of 1.1 dl / g had color spots, large variations in physical properties, and yarn breakage in the spinning step and the drawing step. .. The woven fabric also had color spots and became streaky. Since the viscosity difference between the masterbatch and the diluted resin is large, it is considered that the dispersion of the dyeing agent is non-uniform.
The monofilament for the original screen gauze obtained from Comparative Example 3 using the original masterbatch having an IV of 0.8 dl / g has a low filament strength and is inferior in printing durability when used as a screen gauze. rice field. In addition, yarn breakage occurred in the spinning process and the drawing process, scum occurred during weaving, and the obtained fabric and screen gauze had color spots and became streaky. It is considered that these are because the intrinsic viscosity of the original masterbatch is larger than that of the diluted resin, and the intrinsic viscosity of the masterbatch is higher, so that the dispersion of the adhesive is likely to be non-uniform.
The monofilament for the uncoated screen gauze obtained from Comparative Example 4 in which the concentration of the undiluted agent in the masterbatch was 15% by mass and the dilution ratio of the diluted resin was increased, is prone to scum and color spots. It became. Moreover, the printing durability was inferior. It is considered that these are due to the non-uniform dispersibility due to the high concentration of the adhesive.
The monofilament for the original screen gauze obtained from Comparative Example 5 containing no titanium oxide was a monofilament unsuitable for the screen gauze because halation occurred in the halation evaluation.
The monofilament for screen gauze obtained from Comparative Example 6 in which the ratio of the diluted resin was increased and the concentration of the adhesive as a whole monofilament was 0.2% by mass was inferior in quality due to slight color spots. In addition, halation occurred when the screen was used.
The monofilament for the original screen gauze obtained from Comparative Example 7 in which the titanium oxide concentration of the entire monofilament was 2% by mass caused scum in the spinning process and a little reed scraping during weaving.
The monofilament for the original screen gauze obtained from Comparative Example 8 having an elongation of 15% is said to have low quality of monofilament due to frequent thread breakage in the drawing process, occurrence of fibrillation, and scraping with a reed. became. In addition, the printing durability was low when the screen was used.
The monofilament for the original screen gauze obtained from Comparative Example 9 having an elongation of 50% had low printing durability and low dimensional stability of the mesh.
The monofilament for the original screen gauze obtained from Comparative Example 10 having low intrinsic viscosities of the diluted resin and the original masterbatch had low printing durability when used as the screen gauze.
The monofilament for the original screen gauze obtained from Comparative Example 11 using only the masterbatch of the original adhesive without using the diluted resin has low strength, and the printing durability is very poor when the screen gauze is used. became. In addition, the spinning operability and stretching operability were poor, and scum and knots were generated, resulting in poor quality. The cost was also high.
The monofilament for screen gauze obtained from Comparative Example 12 having a relaxation rate of 0% had pan sink marks during weaving, streaks were formed in the mesh fabric, and the dignity was poor even when the screen gauze was used.
The monofilament for the original screen gauze obtained from Comparative Example 13 having a relaxation rate of 8% was loosened during stretching, and thread breakage occurred frequently and did not reach the evaluation of the screen gauze.
The monofilament for screen gauze obtained from Comparative Example 14 having a spinning speed of 800 m / min had poor drawing operability. This is because the undrawn yarn obtained in the spinning process has a low molecular orientation, a large draw ratio, and a large amount of yarn deformation and a large speed during drawing, so that yarn breakage is likely to occur and knots are also generated. However, it seems that it became a poor quality monofilament.
The monofilament for screen gauze obtained from Comparative Example 15 having a spinning speed of 2500 m / min had low strength of the monofilament and low printing durability when made into a screen gauze. It is considered that this is because the undrawn yarn obtained in the spinning step has a high premolecular orientation, a low draw ratio, and a low strength of the monofilament.
Thread breakage occurred in the monofilament for screen gauze obtained from Comparative Example 16 in which the core-sheath ratio was 3: 7 and the concentration of the moisturizer of the entire monofilament was 0.23% by mass. In addition, since the core component is small, the strength of the monofilament is insufficient, and the printing durability is low when the screen gauze is used.

In this way, the monofilaments for screen screens obtained from Examples 1 to 6 by controlling the intrinsic viscosity of the diluted resin and the masterbatch of the dyeing agent, the addition amount of the dyeing agent, and the like can be used for spinning operability and stretching operability. It was a high-quality, high-strength monofilament for screen gauze with good quality and no color spots, knots, scum, or scraping. In addition, the screen woven fabric obtained from these screen woven monofilaments had no scum or pan-sink during weaving, and was of good quality. Further, the screen gauze had good dimensional stability, no scum, good adhesiveness to the photosensitive resin, no halation, and high quality in printing durability.

Claims (3)

A screen resin containing 0.1 to 1% by mass of a matting agent, 0.3 to 1.2% by mass of an adhesive, a breaking strength of 5.6 to 8 cN / dtex, and a breaking elongation of 20 to 40%. In the method for producing a raw polyethylene terephthalate monofilament, an intrinsic viscosity (IV) of 0.5 to 0.75 dl / g and an intrinsic viscosity of 2 to 12% by mass and an intrinsic viscosity. Using a diluted resin having an (IV) of 0.6 to 1 dl / g, the resin so that the concentration of the primer is 0.3 to 1.2% by mass with respect to the primer master batch and the diluted resin. The first step of melt-spun to obtain undrawn yarn at a spinning speed of 1200 to 1800 m / min, after drawing the obtained undrawn yarn, the relaxation rate is 2 to 6%. A method for manufacturing a monofilament for screen gauze, which comprises a second step of imparting relaxation. The method for producing a monofilament for screen gauze according to claim 1, wherein the monofilament is a fiber in which the coating agent is dispersed over the entire cross section of the fiber. A screen resin raw material containing 0.1 to 1% by mass of a matting agent, 0.3 to 1.2% by mass of an adhesive, a breaking strength of 5.6 to 8 cN / dtex, and a breaking elongation of 20 to 40%. In the method for producing a coated polyethylene terephthalate monofilament, a primer master batch having an intrinsic viscosity (IV) of 0.5 to 0.75 dl / g and a primer concentration of 2 to 12% by mass and an intrinsic viscosity (IV). ) Using a diluted resin of 0.6 to 1 dl / g so that the concentration of the base resin base resin is 0.3 to 1.2% by mass with respect to the base resin master batch and the diluted resin. The core resin is adjusted, a copolymerized polyester having an intrinsic viscosity (IV) of 0.6 to 0.7 dl / g is used as the sheath resin, and the core resin and the sheath resin are melt-extruded, respectively, and the spinning speed is 1200 to. A screen including a first step of melt-spinning at 1800 m / min to obtain an undrawn yarn, and a second step of imparting relaxation with a relaxation rate of 2 to 6% after drawing the obtained undrawn yarn. Manufacturing method of monofilament for gauze.