KR20210084091A - Wet-laid nonwoven fabrics and article comprising the same - Google Patents

Abstract

The present invention relates to a wet non-woven fabric, and more specifically, to a wet non-woven fabric and an article including the same, wherein the non-woven fabric has an excellent feel, mechanical strength and processability, minimizes long-term aging due to excellent heat resistance, and significantly reduces emission of VOCs, so that the non-woven fabric can be applied to various eco-friendly articles.

Description

Wet-laid nonwoven fabrics and article comprising the same

The present invention relates to a wet non-woven fabric, and more particularly, a wet non-woven fabric that has excellent feel, mechanical strength and processability, minimizes change over time due to excellent heat resistance, and significantly reduces the emission of VOCs, so that it can be applied to various eco-friendly articles And it relates to an article comprising the same.

Handmade paper for producing a wet nonwoven fabric is advantageous in that it is produced by dispersing fibers having a short length in water, and thus exhibits significantly better basis weight, thickness, and/or uniformity of formation than a dry nonwoven fabric. However, since short-length fibers must be used to increase and ensure uniform dispersibility of fibers in water, the wet-laid non-woven fabric has very low strength compared to the dry-type non-woven fabric, and such a wet-laid non-woven fabric is generally used in fields that do not require high strength. have.

The wet non-woven fabric is generally manufactured by pressing the hand-made paper through a felt-equipped dryer or a Yankee machine, so the thickness of the wet non-woven fabric is mostly thin, and the density of the non-woven fabric increases due to the press. It is characterized by having a paper-like fabric feel.

Although such a wet-laid nonwoven fabric is being applied to various application products, for example, a filter, a wallpaper, etc., the existing wet-laid nonwoven fabric has a problem of insufficient strength. For this reason, in recent years, there is a trend in manufacturing by adding a binder in order to improve mechanical strength.

As an example of the binder, a heat-adhesive fiber can be considered, and the heat-adhesive fiber has been widely used for the purpose of bonding different types of fibers in a fiber structure used for manufacturing various non-woven fabrics.

For example, as a material having a low melting point to enable thermal bonding, US Patent No. 4,129,675 discloses a low melting point polyester copolymerized using terephthalic acid (TPA) and isophthalic acid (IPA) is introduced. have. In addition, Korea Patent No. 10-1216690 discloses a low-melting polyester fiber embodied including isophthalic acid and diethylene glycol to improve adhesion.

However, the conventional low-melting polyester fiber as described above may have a certain level of spinnability and adhesion, but there is a problem in obtaining a nonwoven or woven structure having a hard feeling after thermal bonding due to the ring structure of the rigid modifier. In addition, as development progresses in the direction of having a low melting point or a low glass transition temperature for the expression of binder properties, the heat resistance of the realized polyester becomes poor, and changes with time occur remarkably even under storage conditions exceeding 40 ° C in summer. There is a problem in that storage stability is also significantly reduced due to the occurrence of bonds between polyester chips or fibers occurring during the process.

In addition, due to the nature of polyester, there is a problem in that VOCs harmful to the human body of the polymer are generated by side reactions that occur in the polymerization process. In other words, one of the main uses of the wet nonwoven is as an air filter and a food filter for tea bags. When the heat-adhesive fiber made of polyester is provided in the wet non-woven fabric, the VOCs contained in the heat-adhesive fiber can be directly exposed to the human body. There is a risk. In addition, even when a wet nonwoven fabric is used as an interior member such as wallpaper, it may not be suitable as it may cause a sick house syndrome problem.

Therefore, it is possible to maintain or improve the spinnability and adhesion properties of conventional heat-adhesive fibers, as well as remarkably improved tactile feel, minimize change over time at room temperature and high temperature, and improve storage stability, and excellent dispersibility And it is urgent to develop a wet nonwoven fabric with a small amount of VOCs.

US Patent No. 4,129,675 Korean Patent Registration No. 10-1216690

The present invention was devised in consideration of the above points, and it has excellent touch, adhesive strength and processability, and excellent heat resistance minimizes changes over time. VOCs emission is remarkably reduced to be eco-friendly, so it can be used as a water filter, tea bag, etc. An object of the present invention is to provide a wet nonwoven fabric that can be widely applied to interior members such as filter members and wallpaper, and articles including the same.

In order to solve the above problems, the present invention provides a first fiber having a fiber length of 1 to 30 mm; and

It includes a copolyester obtained by polycondensation of an acid component containing terephthalic acid, and an esterified compound in which ethylene glycol and a diol component containing a compound represented by the following Chemical Formula 1 and Chemical Formula 2 are reacted, and the fiber length is 1 It provides a wet non-woven fabric comprising; a second fiber of ~ 30 mm.

[Formula 1]

[Formula 2]

According to an embodiment of the present invention, the total content of the compound represented by Formula 1 and the compound represented by Formula 2 may be included in an amount of 30 to 45 mol% of the diol component.

In addition, the content (mol %) of the compound represented by Formula 1 among the diol components may be greater than the content (mol %) of the compound represented by Formula 2 .

In addition, the diol component may not include diethylene glycol.

In addition, the acid component may be further included in an amount of 1 to 10 mol% of isophthalic acid based on the acid component.

In addition, 1 to 40 mol% of the compound represented by Formula 1 among the diol components, 0.8 to 20 mol% of the compound represented by Formula 2 may be included, and more preferably, the compound represented by Formula 1 among the diol components The compound represented by 20 to 40 mol%, the compound represented by Formula 2 is 0.8 to 10 mol%, more preferably, the compound represented by Formula 1 is 30 to 40 mol%, the compound represented by Formula 2 is It may be included in 0.8 to 6 mol%.

In addition, the copolyester may have a glass transition temperature of 60 to 75 ℃, more preferably 65 to 72 ℃.

In addition, the copolyester may have an intrinsic viscosity of 0.500 to 0.800 dl/g.

In addition, the second fiber may have a fiber water dispersibility of 0.040% or less according to Equation 1 below.

[Equation 1]

The number of undispersed fibers is measured by adding 3 g of a second fiber having a moisture content of 25% by weight to 1 liter of water at a temperature of 25° C., followed by stirring for 10 minutes under the conditions of 600 rpm, leaving it for 1 minute, and then measuring the number of undispersed fibers. .

In addition, the first fiber may include at least one selected from the group consisting of cellulose fibers, polyester fibers, polyamide fibers, and polyolefin-based fibers.

In addition, the second fiber may have an amount of acetaldehyde (AA) generated according to MS300-55 of 2400 ppb or less, more preferably 1950 ppb or less, even more preferably 1600 ppb or less.

In addition, the present invention provides a filter member or an interior member comprising the wet nonwoven fabric according to the present invention.

The wet nonwoven fabric according to the present invention is very excellent in touch, adhesive strength and workability. In addition, the heat-adhesive fiber provided in the wet nonwoven fabric has excellent heat resistance, so that change over time is minimized. Furthermore, since the emission of VOCs is significantly reduced and it is eco-friendly, it can be widely applied to water filters, filter members such as tea bags, and interior members such as wallpaper.

1 is a schematic cross-sectional view of a second fiber included in an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail so that those of ordinary skill in the art to which the present invention pertains can easily implement them. The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

Referring to FIG. 1 , the wet nonwoven fabric according to the present invention may include a first fiber and a second fiber, and more specifically, the first fiber and the second fiber may be included in a dispersed state.

The first fiber and the second fiber each independently have a fineness of 1 to 30 mm, which is obtained by dispersing the first fiber and the second fiber in water. This is to obtain a more uniform hand-made paper by improving acidity. If the fiber length is less than 1 mm, there is a possibility that the mechanical strength of the wet-laid nonwoven fabric may be greatly reduced, and there may be a problem of poor paper transfer during the process due to the decrease in strength. In addition, if it exceeds 30 mm, the uniformity of the implemented wet nonwoven fabric, for example, the uniformity of any one or more of basis weight, thickness, and formation may be reduced.

The first fiber is a base fiber of the wet nonwoven fabric, and is a fiber that realizes the shape and strength of the wet nonwoven fabric. The first fiber may be used without limitation in the case of the main fiber typically used for manufacturing paper or synthetic paper, as an example, from the group consisting of cellulose fibers (eg pulp), polyester fibers, polyolefin fibers and polyamide fibers. It may include one or more selected.

The first fiber may have a fineness of 0.5 to 20 denier. If the fineness of the first fiber is less than 0.5 denier, there is a fear that the air permeability may decrease, and if it exceeds 20 denier, the uniformity of the wet nonwoven fabric may be reduced there is

The second fiber is a fiber that thermally bonds between the first fiber and the second fiber and/or between the second fiber after being uniformly dispersed with the first fiber, which itself guarantees the shape implementation and mechanical strength of the wet nonwoven fabric It can be used as a fiber.

The second fiber is a copolyester in which an acid component containing terephthalic acid, and an esterified compound in which ethylene glycol and a diol component containing a compound represented by the following Chemical Formula 1 and Chemical Formula 2 are reacted are polycondensed. include

[Formula 1]

[Formula 2]

First, the acid component includes terephthalic acid, and other than terephthalic acid, an aromatic polyhydric carboxylic acid having 6 to 14 carbon atoms, or an aliphatic polyhydric carboxylic acid having 2 to 14 carbon atoms and/or a sulfonic acid metal salt.

The aromatic polyhydric carboxylic acid having 6 to 14 carbon atoms may be used without limitation as an acid component used for the production of polyester, but is preferably selected from the group consisting of dimethyl terephthalate, isophthalic acid and dimethyl isophthalate. It may be one or more, and more preferably may be isophthalic acid in terms of reaction stability with terephthalic acid, ease of handling and economical aspects.

In addition, the aliphatic polyhydric carboxylic acid having 2 to 14 carbon atoms may be used without limitation as an acid component used for the production of polyester, but as a non-limiting example thereof, oxalic acid, malonic acid, succinic acid, glutar Acid, adipic acid, suberic acid, citric acid, pimeric acid, azelaic acid, sebacic acid, nonanoic acid, decanoic acid, dodecanoic acid and hexanodecanophosphoric acid may be at least one selected from the group consisting of.

In addition, the sulfonic acid metal salt may be sodium 3,5-dicarbomethoxybenzene sulfonate.

On the other hand, as the acidic component, other components that may be included in addition to terephthalic acid may reduce the heat resistance of the copolyester, so it is preferable not to include it. In particular, when an acid component such as isophthalic acid or dimethyl isophthalate is further included, the content of VOCs generated in the polycondensation process of the copolyester, for example, the content of acetaldehyde may increase, whereas the melting point of the copolyester The content of acetaldehyde in the resulting fiber may be high because it is further lowered and it is difficult to vaporize and remove acetaldehyde generated in the polymerization process through a subsequent process such as heat treatment. When isophthalic acid is further included, it may be provided in an amount of 1 to 10 mol% based on the acid content, and when it is provided in excess of 10 mol%, there is a risk that the acetaldehyde content may be excessively increased, and the heat-adhesive fiber implemented by this may not be suitable for automotive interior applications.

Next, the diol component includes ethylene glycol, a compound represented by the following formula (1) and a compound represented by the formula (2).

[Formula 1]

[Formula 2]

First, the compound represented by Chemical Formula 1 may lower the crystallinity and the glass transition temperature of the copolyester to exhibit excellent thermal bonding performance. In addition, it makes the dyeing process easier by enabling dyeing under normal pressure conditions in the dyeing process after being manufactured into fibers, and has excellent dyeing properties to improve wash fastness, and to improve the tactile feel of the fiber aggregate. Preferably, the compound represented by Formula 1 among the diol components may be included in an amount of preferably 20 to 40 mol%, more preferably 30 to 40 mol%. In particular, when 20 mol% or more of the compound represented by the formula (1) is provided, the copolyester implemented with the compound represented by the formula (2), which will be described later, further increases and improves the thermal adhesive properties at low temperatures, and the copolyester The drying time can be significantly shortened when manufactured as a chip, and there is an advantage that a synergistic effect can be expressed in reducing the content of VOCs emitted from the second fiber manufactured by the copolyester chip.

If the compound represented by Formula 1 is contained in an amount of less than 20 mol% based on the diol component, the spinnability is excellent, but there is a concern that the adhesive temperature is increased or the thermal adhesive property is lowered, and the use may be limited. In addition, there is a concern that the content of VOCs emitted from the implemented heat-adhesive fiber increases. In addition, if the compound represented by Formula 1 is provided in excess of 40 mol%, it may be difficult to commercialize due to poor spinning into the heat-adhesive fiber, and rather, the crystallinity may increase and the heat-adhesive property may be lowered. There are concerns. In addition, interfiber bonding occurs in the heating process such as the stretching process performed to manufacture the second fiber, so that the second fibers may agglomerate in the final wet nonwoven fabric, and there is a risk of a decrease in strength and a decrease in tactile feel.

The compound represented by the formula (2) further improves the thermal adhesion properties of the copolyester prepared together with the compound represented by the formula (1), and prevents the glass transition temperature of the compound represented by the formula (1) from significantly lowering, thereby providing excellent thermal performance. to express the characteristics. For example, in spite of the stretching process performed at a storage temperature of 25°C or higher and hot water of 60°C or higher, it is possible to minimize changes over time and agglomeration due to bonding between fibers. In addition, the manufactured wet nonwoven fabric can be utilized as an article for applications where a high-temperature environment is created, and storage stability can be improved. On the other hand, in relation to thermal adhesiveness, the compound represented by Formula 2 exhibits appropriate shrinkage properties to the heat-adhesive fiber using copolyester realized as it is mixed with the compound represented by Formula 1, and due to this characteristic expression, heat By further increasing the point adhesion during bonding, it is possible to express more elevated thermal bonding properties.

Preferably, among the diol components, the compound represented by Formula 2 may be included in an amount of preferably 0.8 to 10 mol%, more preferably 0.8 to 6 mol%.

If the compound represented by Formula 2 is included in an amount of less than 0.8 mol% based on the diol component, it is difficult to improve the desired heat resistance, so storage stability is not good, and there is a concern that the change over time may be very large. In addition, inter-fiber bonding may occur in the stretching process performed in hot water at a temperature of 60° C. or higher, which may result in a wet nonwoven fabric with reduced dispersibility of the second fiber. There is a possibility that the content may increase.

In addition, if the compound represented by Formula 2 is included in excess of 10 mol%, considering that it is used together with the compound represented by Formula 1 described above, it is difficult to commercialize due to poor spinning to the heat-adhesive fiber. , in some cases, when additional isophthalic acid is included, the crystallinity is sufficiently lowered and the improvement in adhesiveness is insignificant, and when the content of added isophthalic acid is increased, the crystallinity is rather increased, resulting in excellent thermal adhesive properties at the desired temperature. There is a fear that the object of the invention may not be achieved, such as this may be significantly reduced. In addition, when implemented in a fibrous form, shrinkage is significantly expressed, so there may be difficulties in yarn processing such as a stretching process or manufacturing or processing of a wet nonwoven fabric.

According to a preferred embodiment of the present invention, the total content of the compound represented by Formula 1 and the compound represented by Formula 2 is preferably included in an amount of 30 to 45 mol% of the diol component, more preferably 33 to It may be included in 41 mol%. If they are included in less than 30 mol%, the crystallinity of the copolyester increases and a high melting point is expressed or it becomes difficult to implement a softening point at a low temperature, so that the heat-bonding temperature is significantly increased, and excellent heat-adhesive properties are expressed at a low temperature It may not work, and the bonding strength may be lowered. In addition, there is a concern that the content of VOCs emitted from the implemented heat-adhesive fiber increases.

In addition, if the compound represented by Formula 2 is included in excess of 45 mol%, there is a concern that polymerization reactivity and radioactivity are significantly reduced, and the crystallinity of the prepared copolyester is rather increased, resulting in high thermal adhesion at a desired temperature. Characteristics can be difficult to express. In addition, the bonding between the fibers may be remarkable after the stretching process in hot water at a temperature of 60° C. or higher, and this may make it difficult for the second fiber to be evenly dispersed, making it difficult to implement a wet nonwoven fabric of excellent quality.

In this case, in the diol component, the compound represented by Formula 1 may be included in a greater content (mol%) than the compound represented by Formula 2. If the compound represented by Formula 1 is included in an amount less than or equal to that of the compound represented by Formula 2, it is difficult to express the desired thermal adhesive properties, and as it must be adhered at a high temperature, the use of the developed product may be limited. In addition, there is a fear that it may be difficult to process or utilize the developed product due to the expression of excessive shrinkage characteristics.

Meanwhile, the diol component may further include other types of diol components in addition to the compound represented by Formula 1, the compound represented by Formula 2, and ethylene glycol.

Since the other type of diol component may be a known diol component used in the production of polyester, the present invention is not particularly limited thereto, but as a non-limiting example thereof, it may be an aliphatic diol component having 2 to 14 carbon atoms, , specifically 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, propylene glycol, trimethyl glycol, tetramethylene glycol, pentamethyl glycol, hexamethylene glycol, heptamethylene glycol, octamethylene glycol , may be any one or more selected from the group consisting of nonamethylene glycol, decamethylene glycol, undecamethylene glycol, dodecamethylene glycol and tridecamethylene glycol.

However, in order to combine heat resistance with a desired level of thermal bonding properties, it is preferable that the other types of diol components are not further included, and in particular, diethylene glycol may not be included in the diol components. If diethylene glycol is included in the diol component, it may cause a rapid decrease in the glass transition temperature, so that even when the compound represented by Formula 2 is included, the desired level of heat resistance may not be achieved. In addition, there is a concern that the content of VOCs emitted during use will greatly increase. On the other hand, the meaning that diethylene glycol is not included in the diol component means that diethylene glycol is not intentionally added as a monomer for the production of copolyester, and esterification reaction, polymerization/condensation of the acid component and the diol component It does not mean that even diethylene glycol generated as a by-product in the reaction is not included. Since diethylene glycol can occur naturally as a by-product, according to an embodiment of the present invention, the chip including copolyester may contain diethylene glycol generated as a by-product in addition to copolyester, and the content of diethylene glycol contained is It may be less than 3% by weight based on the weight of the copolyester in the polyester chips or secondary fibers. On the other hand, if the content of diethylene glycol generated as a by-product exceeds an appropriate level, the pack pressure increases when spinning into fibers, and the spinnability may be significantly reduced by causing frequent thread cutting, and the content of emitted VOCs, especially acetaldehyde There is a possibility that the emission amount is significantly increased.

The above-mentioned acid component and diol component can be prepared as copolyester through esterification reaction and polycondensation using known synthesis conditions in the field of polyester synthesis. At this time, the acid component and the diol component may be added to react in a molar ratio of 1: 1.0 to 5.0, preferably 1: 1.0 to 2.0, but is not limited thereto. If the molar ratio is less than 1 times the diol component based on the acid content, the acidity during polymerization may be excessively high and side reactions may be accelerated. If the molar ratio exceeds 5 times the diol component based on the acid component, the polymerization degree may not increase. have.

On the other hand, the acid component and the diol component are mixed at a time in an appropriate molar ratio as described above, and then undergo esterification reaction and polycondensation to prepare a copolyester, or between ethylene glycol and the compound represented by Formula 1 among the acid component and the diol component. The compound represented by Chemical Formula 2 may be added during the esterification reaction, and the copolyester may be prepared through an esterification reaction and polycondensation, and the present invention is not particularly limited thereto.

A catalyst may be further included in the esterification reaction. The catalyst may be a catalyst typically used in the production of polyester, and as a non-limiting example thereof, may be prepared under a metal acetate catalyst.

In addition, the esterification reaction may be preferably performed at a temperature of 200 to 270° C. and a pressure of 1100 to 1350 Torr. If the above conditions are not satisfied, there may be problems in that an esterification compound suitable for a polycondensation reaction cannot be formed due to a prolonged esterification reaction time or reduced reactivity.

In addition, the polycondensation reaction may be carried out at a temperature of 250 to 300 ° C and a pressure of 0.3 to 1.0 Torr, and if the above conditions are not satisfied, there may be problems such as a reaction time delay, a decrease in polymerization degree, and thermal decomposition. . In addition, the polycondensation reaction may be carried out for 150 to 240 minutes, for example, although the reaction time may vary depending on the reaction conditions.

In this case, a catalyst may be further included in the polycondensation reaction. The catalyst may be used without limitation in the case of known catalysts used in the production of polyester resins. However, preferably, it may be a titanium-based polymerization catalyst, and more specifically may be a titanium-based polymerization catalyst represented by the following formula (3).

[Formula 3]

The titanium-based polymerization catalyst represented by Chemical Formula 3 is stable even in the presence of water molecules. For this reason, the esterification reaction and polycondensation reaction may proceed within a shorter time than before, as water is not deactivated even if it is added before the esterification reaction in which a large amount of water is by-produced, and through this, coloring due to yellowing can be suppressed. . The catalyst may be included in an amount of 5 to 40 ppm in terms of titanium atoms based on the total weight of the obtained copolyester, which is preferable because thermal stability or color tone of the copolyester is improved. If it is provided at less than 5 ppm in terms of titanium atoms, it may be difficult to properly promote the esterification reaction, and if it is provided in excess of 40 ppm, there may be a problem in that the reactivity is promoted but coloring occurs.

Meanwhile, a thermal stabilizer may be further included during the polycondensation reaction. The thermal stabilizer is to prevent discoloration of color through thermal decomposition at high temperature, and a phosphorus-based compound may be used. The phosphorus compound is preferably phosphoric acid, monomethyl phosphoric acid, trimethyl phosphoric acid, triethyl phosphoric acid, etc. and derivatives thereof. Among them, trimethyl phosphoric acid or triethyl phosphoric acid is more preferable because of its excellent effect. The amount of the phosphorus compound used is preferably 10 to 30 ppm in terms of phosphorus atoms based on the total weight of the finally obtained copolyester. If the phosphorus-based thermal stabilizer is used at less than 10 ppm, it is difficult to prevent high-temperature thermal decomposition, so the copolyester may be discolored. If it exceeds 30 ppm, it may be disadvantageous in terms of manufacturing cost and inhibit catalyst activity by the thermal stabilizer during polycondensation reaction. Therefore, there may be a problem that a reaction delay phenomenon occurs.

In addition, the copolyester may further include a complementary colorant. The complementary colorant is for adjusting the color tone to make the color of the dyed dye stronger and better in the dyeing process proceeding after being spun into the fiber, and it can be added to one known in the textile field, and as a non-limiting example thereof, There are wear dyes, pigments, vat dyes, disperse dyes, and organic pigments. However, preferably, a mixture of blue and red dyes may be used. This is because a cobalt compound generally used as a complementary colorant is undesirable because it is harmful to the human body, whereas a complementary colorant containing blue and red dyes is harmless to the human body and is preferable. In addition, when a mixture of blue and red dyes is used, there is an advantage in that the color tone can be finely controlled. The blue dye may include, for example, solvent blue 104, solvent blue 122, and solvent blue 45, and the red dye may include, for example, solvent red 111, solvent red 179, and solvent red 195. In addition, the blue dye and the red dye can be mixed in a weight ratio of 1: 1.0 to 3.0, which is advantageous to express a remarkable effect in a desired fine color tone control.

The complementary color agent may be provided in an amount of 1 to 10 ppm based on the total weight of the copolyester. If the amount is less than 1 ppm, it may be difficult to achieve a desired level of complementary color properties, and if it exceeds 10 ppm, the L value is reduced. Therefore, there may be a problem that transparency is lowered and a dark color is displayed.

The copolyester prepared through the above-described method may have an intrinsic viscosity of 0.5 to 0.8 dl/g. If the intrinsic viscosity is less than 0.5 dl/g, it may not be easy to form a cross-section after being spun into the fiber, and if the intrinsic viscosity exceeds 0.8 dl/g, there is a risk that the spinnability may be reduced due to high pack pressure.

In addition, the copolyester may have a glass transition temperature of 66.8 ~ 75 ℃, through which it may be more advantageous to achieve the object of the present invention. If the glass transition temperature is less than 66.8 ℃, the secondary fiber or the embodied article including the same may have a large change with time even in temperature conditions exceeding 40 ℃, such as in summer. In addition, when the heat-adhesive fiber is produced, the occurrence of bonds between the copolyester chips increases, which may cause spinning defects. Furthermore, there is a risk that the shrinkage characteristic is excessively expressed after being implemented with fibers, etc. In addition, due to the limitation of heat treatment required for the drying process after chip formation and post-processing (eg stretching process) after spinning into fibers, there is a risk that the process duration may be prolonged or bonding between fibers may occur. There is a risk of deterioration.

In addition, if the glass transition temperature exceeds 75 ℃, there is a fear that the thermal bonding properties are significantly lowered, there is a fear that the performance temperature of the bonding process may be limited to a high temperature.

The above-described second fiber is a single fiber produced by spinning only copolyester, or as shown in FIG. 1 , the second fiber 10 has a core 11 and a sheath 12 surrounding the core 11. It may be a composite fiber comprising a. The above-described copolyester may be included in the sheath 12 in the composite fiber.

The core 11 functions as a support component of the composite fiber, and may include, for example, a polyester-based component. The polyester-based component is not limited in the case of a polyester-based component having a melting point or softening point higher than the melting point or softening point of the copolyester provided in the sheath 12 described above, and may be, for example, polyethylene terephthalate.

The second fiber 10 may be, for example, a composite spinning of the core 11 and the sheath 12 in a weight ratio of 8:2 to 2:8, but is not limited thereto, and the ratio may be appropriately adjusted according to the purpose. can radiate The spinning conditions for the second fiber 10, the spinning device, and the process of cooling and drawing the composite fiber after spinning can be performed through known conditions, devices and processes in the art or by appropriately modifying them. The present invention is not particularly limited in this respect. In addition, as an example, the second fiber may be spun at a spinning temperature of 270 to 290°C, and may be stretched 2.5 to 4.0 times in hot water at 60°C after spinning.

On the other hand, according to an embodiment of the present invention, since the second fiber has excellent thermal properties, the occurrence of bonding between fibers can be minimized or prevented even after post-processing such as drawing in hot water. The fiber water dispersibility may be 0.040% or less.

[Equation 1]

The number of undispersed fibers is measured by adding 3 g of a second fiber having a moisture content of 25% by weight to 1 liter of water at a temperature of 25° C., followed by stirring for 10 minutes under the conditions of 600 rpm, leaving it for 1 minute, and then measuring the number of undispersed fibers. .

If the water dispersibility according to Equation 1 exceeds 0.040%, the wet nonwoven fabric made of these second fibers has reduced mechanical strength uniformity, and the number of second fibers that are agglomerated when dispersed in water at a temperature of 25° C. or higher. is remarkable, and the tactile feel of the paper made through this may be reduced, and there is a risk of product defects due to an increase in defects in the paper. On the other hand, papermaking can be used for interior purposes, and the aesthetics and feel of the exterior are very important when observed with the naked eye. Subsequent management can be very important for the quality of the product.

In addition, the second fiber may have a fineness of 1 to 20 denier, if the fineness of the second fiber is less than 1 denier, there is a risk of causing defects in the papermaking due to poor spinning mobility, and if the fineness exceeds 20 denier In the case of spinning, it has poor mobility due to poor solidification, which can also cause defects in papermaking.

In addition, the wet nonwoven fabric may include, for example, the first fiber and the second fiber in a weight ratio of 1: 0.05 to 1.2, but is not limited thereto, and the weight ratio may be appropriately adjusted according to the purpose.

In addition, when explaining the manufacturing process of the wet nonwoven fabric, (1) manufacturing a hand made paper by mixing the first fiber and the second fiber prepared to have a predetermined length, (2) manufacturing the hand made paper by drying the prepared hand made paper and (3) calendering by applying at least one of heat and pressure to the prepared papermaking paper. A wet nonwoven fabric may be manufactured.

In step (1), the first fiber and the second fiber are evenly dispersed in a dispersion medium to prepare a hand-made paper, and the dispersion medium may be a known dispersion medium such as water. The fibers mixed in the dispersion medium may be further subjected to a blending process for uniform mixing, and may further include various other substances such as a pH-adjusting material, a forming aid, a surfactant, an antifoaming agent, etc. to improve dispersibility.

The production of the hand-made paper can be manufactured using a paper machine, and it is not limited to the type of paper machine, such as a Jang-mang paper machine, a Hwan-mang paper machine, and can be used by changing it according to the purpose.

Next, as the step (2), a step of manufacturing the papermaking by drying the prepared handmade paper is performed.

Prior to the drying process for the prepared handicraft paper, a drainage process of the dispersion medium may be further performed. In addition, after the draining process, the dehydration process may be further performed by vacuum or other pressure. Papermaking may be made by evaporating the residual dispersion medium using a dryer, oven, or similar apparatus known in the art for drying paper on drained, dewatered handcraft paper.

Next, as step (3), calendering is performed by applying at least one of heat and pressure to the prepared papermaking paper.

A preliminary compression step may be further performed before the calendering step, and the heat and/or pressure may be simultaneously achieved by heating a roller to apply pressure, or may be achieved through different processes. However, the heat treatment may be performed by any heating method, such as by bringing the paper into contact with a metal roll or other high-temperature surface, and may also be achieved by a conventional method such as infrared or high-temperature air heating in an oven. Since the applied heat can be determined in consideration of the types and thermal characteristics of the first and second fibers, the present invention is not particularly limited thereto.

On the other hand, the second fiber contained in the wet nonwoven fabric manufactured through the above manufacturing method may have an acetaldehyde (AA) generation amount of 2400 ppb or less, more preferably 1950 ppb or less, even more preferably 1600 ppb or less based on MS300-55. Through this, even if it is used for interior members such as wallpaper or filter members such as tea bags/water filters, the amount of harmful ingredients is significantly small, so it has the advantage that it can be widely used as a member in contact with the human body or provided in a space where people live. have.

In addition, since the thickness and basis weight of the wet nonwoven fabric may be the thickness and basis weight of a wet nonwoven fabric conventional in the art, the present invention is not particularly limited thereto.

The above-described filter member or interior member may include at least one layer or more of the wet nonwoven fabric according to an embodiment of the present invention. In addition, a support may be further included to supplement mechanical strength, and the support may be provided in a known filter member or interior member. In addition, the filter member or the interior member may further include other components provided in a known filter member or interior member in addition to the support, and the present invention is not particularly limited thereto.

The present invention will be described in more detail through the following examples, but the following examples are not intended to limit the scope of the present invention, which should be construed to aid understanding of the present invention.

<Example 1>

38 mol% of the compound represented by the following Chemical Formula 1 as a diol component, 3 mol% of the compound represented by the following Chemical Formula 2, and 59 mol% of ethylene glycol as the remaining diol component were added, and 100 mol% of terephthalic acid was added as an acid component to the acid An ester reaction product was obtained by esterifying the powder and the diol component at a ratio of 1:1.2 at 250° C. under a pressure of 1140 torr, and the reaction rate was 97.5%. The formed ester reactant is transferred to a polycondensation reactor, and 15 ppm of the compound represented by the following Chemical Formula 3 (based on Ti element) as a polycondensation catalyst and 25 ppm of triethyl phosphoric acid (based on P element) as a heat stabilizer are added to a final pressure of 0.5 Torr. The copolyester was prepared by carrying out a polycondensation reaction by gradually increasing the temperature to 285° C. under reduced pressure, and then the copolyester was prepared into polyester chips each having a width, length, and height of 2 mm × 4 mm × 3 mm in a conventional manner. .

Then, in order to prepare a core-sheath composite fiber using the copolyester as a sheath and polyethylene letephthalate (PET) having an intrinsic viscosity of 0.65 dl/g as a core, the copolyester chips are put into a hopper and then melted. After putting each in a core-sheath spinneret, composite spinning at a spinning speed of 1000mpm under 275℃ so that the core and sheath parts have a 5:5 weight ratio, stretched 3.0 times in hot water at 60℃, the fiber length is 6mm, and the fineness is 4.0de A core-sheath type heat-adhesive second fiber as shown in Table 1 was prepared.

[Formula 1]

[Formula 2]

[Formula 3]

Thereafter, the second fiber and the first fiber (fiber length 6 mm, fineness 4.0de), which is polyethylene terephthalate (PET), were dispersed in water at 25 ° C in a ratio of 5: 5 and then dried at 100 ° C after draining the water, A total of three types of wet nonwoven fabrics having a basis weight of 80 g/m 2 were prepared by calendering again under temperature conditions of 120° C., 140° C. and 160° C., respectively.

<Examples 2 to 14>

It was prepared in the same manner as in Example 1, but by changing the composition ratio of the monomers for preparing the copolyester as shown in Table 1, Table 2 or Table 3 below, core-sheath composite fiber as shown in Table 1, Table 2 or Table 3 A wet nonwoven fabric having a phosphorus second fiber was prepared.

<Comparative Examples 1 to 4>

It was prepared in the same manner as in Example 1, except that the composition of the monomer for preparing the copolyester was changed as shown in Table 3 below to include a polyester chip as shown in Table 3 and a second fiber, which is a core-sheath type composite fiber using the same. A wet nonwoven fabric was prepared.

<Experimental Example 1>

The following physical properties were evaluated for the wet nonwoven fabric implemented according to Examples and Comparative Examples, and the copolyester chip as an intermediate during the production of the wet nonwoven fabric or the second fiber, which is a core-sheath type composite fiber, and the results are presented in Tables 1 to Tables below. 3 is shown.

1. Intrinsic Viscosity

For copolyester chips, ortho-chlorophenol (Ortho-Chloro Phenol) as a solvent was melted at 110°C, 2.0 g/25ml concentration for 30 minutes, followed by constant temperature at 25°C for 30 minutes, to which a CANON viscometer was connected. Analyzed from an automatic viscometer.

2. Glass transition temperature, melting point

The glass transition temperature and melting point of the copolyester were measured using a differential calorimeter, and the analysis condition was a temperature increase rate of 20° C./min.

3. Copolyester Chip Drying Time

After the polycondensed copolyester resin was chipped, the moisture content was measured in a vacuum dryer at 55° C., every 4 hours, and when the moisture content was measured to be less than 100 ppm as a result of the measurement, the time was indicated as the drying time.

4. Short fiber storage stability

For 500 g of the manufactured core-sheath composite fiber, pressure of 2kgf/cm2 was applied in a chamber with a temperature of 40℃ and a relative humidity of 45% and left for 3 days, and 10 experts visually observed the fusion state between the fibers. After evaluation as 0 to 10 points, the average value was calculated on the basis of 10 points for cases and 0 points for all cases where fusion occurred. As a result, when the average value was 9.0 or more, it was indicated as very good (◎), when it was 7.0 or more and less than 9.0, it was excellent (○), 5.0 or more and less than 7.0 were average (Δ), and less than 5.0 was bad (×).

5. Radiation workability

The spinning workability of the core-sheath composite fiber, which is the second fiber spun at the same content in Examples and Comparative Examples, during the spinning process (a lump formed by partially fusion of the fiber strands passing through the slit or irregular fusion of the strands after trimming) Meaning) The occurrence value was counted through a drip detector, and the number of drips generated in the remaining Examples and Comparative Examples was expressed as a relative percentage based on the drip occurrence value in Example 1 as 100.

6. Evaluation of dyeing rate

After performing the dyeing process for 60 minutes at 90°C with a bath ratio of 1:50 for a dye solution containing 2% by weight of blue dye based on the weight of the core-sheath type composite fiber, KURABO, Japan After measuring the spectral reflectance in the visible region (360 ~ 740nm, 10nm interval) of the dyed composite fiber using the company's color measurement system, the Total K/S value, which is an index of the amount of dyeing based on the CIE 1976 standard, is calculated. The color yield of the dye was evaluated.

7. Adhesive strength

Each of the three fiber aggregates was implemented as a specimen having a width, length, and thickness of 100 mm × 20 mm × 10 mm, respectively, and the adhesive strength was measured using a universal testing machine (UTM) according to the KS M ISO 36 method.

On the other hand, when the shape was deformed due to excessive shrinkage during heat treatment, the adhesive strength was not evaluated, but 'shape deformation' was evaluated.

8. Soft touch

Among the three types of fiber aggregates, a sensory test was conducted by a group of 10 experts in the same industry on the fiber aggregates manufactured by heat treatment at a temperature of 140℃. ), 6-7 people were classified as good (○), 5-4 people as normal (Δ), and less than 4 people as bad (×).

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 acid
(mole%) TPA 100 100 100 100 100 100 100 IPA 0 0 0 0 0 0 0 total 100 100 100 100 100 100 100 Dior
ingredient
(mole%) EG 59 56 53.5 50 66 69.5 71.5 compound of formula 1 38 39 40 47 32.8 27.5 25.5 compound of formula 2 3 5 6.5 3 1.2 3 3 DEG 0 0 0 0 0 0 0 total 100 100 100 100 100 100 100 Formula 1 + Formula 2 41 44 46.5 50 34 30.5 28.5 polyester chips IV 0.628 0.632 0.632 0.638 0.643 0.640 0.645 Melting point (℃) none none none none none none 187 Tg(℃) 68 68 67 63 67 71 73 Drying time (Hr) 44 44 44 48 44 28 24 second fiber Spinning workability (%) 100 100 116 285 97 92 90 short fiber storage stability ◎ ◎ ◎ ○ ◎ ◎ ◎ Dyeing rate (K/S) 16 17 17 15 14 12 11 Wet nonwoven fabric 120℃ Adhesive Strength (N) 66 64.2 53.4 39 37.8 22.8 non-adhesive 140℃ Adhesive Strength (N) 84.6 83.4 82.8 69 62.4 36 28.2 160℃ Adhesive Strength (N) 110.4 107.4 105.6 103.8 83.4 54.6 45.6 soft feel ◎ ◎ ◎ ◎ ○ △ △

Example 8 Example 9 Example 10 Example 11 Example 12 acid
(mole%) TPA 100 100 100 100 100 IPA 0 0 0 0 0 total 100 100 100 100 0 Dior
Ingredients (mol%) EG 69.5 69.5 67 72 66 compound of formula 1 21 18.5 21 18.5 33.5 compound of formula 2 9.5 12 12 9.5 0.5 DEG 0 0 0 0 0 total 100 100 100 100 100 Formula 1 + Formula 2 30.5 30.5 33 28 34 polyester chips IV 0.643 0.640 0.642 0.643 0.638 Melting point (℃) none none none 187 none Tg(℃) 72 73 72 73 67 Drying time (Hr) 24 20 24 20 48 second fiber Spinning workability (%) 86 84 98 81 108 short fiber storage stability ◎ ◎ ◎ ◎ ○ Dyeing rate (%) 13 11 13 11 15 Wet nonwoven fabric 120℃ Adhesive Strength (N) 42.48 27.14 35.4 non-adhesive 25.37 140℃ Adhesive Strength (N) 66.67 52.51 57.82 17.11 53.1 160℃ Adhesive Strength (N) 82.6 78.47 83.19 30.68 73.75 soft feel △ △ △ △ ○

Example 13 Example 14 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 acid
(mole%) TPA 100 97 100 100 80 100 IPA 0 3 0 0 20 0 total 100 100 100 100 100 100 Dior
Ingredients (mol%) EG 60 62 63 60 80 63 compound of formula 1 15 35 37 33 0 0 compound of formula 2 22 3 0 0 10 37 DEG 0 0 0 7 10 0 total 100 100 100 100 100 100 Formula 1 + Formula 2 37 38 37 33 10 37 polyester chips IV 0.653 0.635 0.642 0.640 0.638 0.638 Melting point (℃) none none none none none none Tg(℃) 72 66 65 62 66 75 Drying time (Hr) 28 44 52 52 56 20 second fiber Spinning workability (%) 360 96 110 155 220 486 short fiber storage stability ◎ ◎ ○ × △ ◎ Dyeing rate (%) 13 16 16 16 15 13 Wet nonwoven fabric 120℃ Adhesive Strength (N) shape change 72 54.6 45 58.8 shape change 140℃ Adhesive Strength (N) shape change 85.8 75.6 62.4 77.4 shape change 160℃ Adhesive Strength (N) shape change 98.4 91.2 81.6 90.6 shape change soft feel - ◎ ◎ ◎ ◎ -

As can be seen from Tables 1 to 3,

Comparative Examples have significantly prolonged drying time (Comparative Examples 1 to 3), remarkably poor spinning workability (Comparative Example 2, Comparative Example 3), or very poor short fiber storage stability (Comparative Example 2, Comparative Example 3) ), it can be seen that the shape is deformed (Comparative Example 4) in the evaluation of adhesive strength by temperature, so it can be confirmed that all physical properties cannot be satisfied at the same time, but it can be confirmed that the Examples express all the physical properties at an excellent level .

On the other hand, in Example 13, in which the content of the compound represented by Formula 2 is higher than that of the compound represented by Formula 1 in the Examples, the shape is deformed in the adhesive strength evaluation by temperature compared to other Examples to achieve the desired physical properties. It can be found that is not suitable for

<Examples 15 to 24>

It was prepared in the same manner as in Example 1, except that the composition of the second fiber was changed as shown in Table 4 below to prepare a wet nonwoven fabric having the second fiber as shown in Table 4 below.

<Experimental Example 2>

The following physical properties of the second fibers in the wet nonwoven fabrics prepared in Examples 15 to 24 were evaluated, and the results are shown in Table 4 below.

1. Acetaldehyde (AA) content

The second fiber was measured according to the MS 300-55 Method.

2. Water dispersibility evaluation

After adding 3 g of the second fiber having a moisture content of 25% by weight to 1 liter of water at a temperature of 25° C., stirring it for 10 minutes under the condition of 600 rpm, leaving it for 1 minute, and then measuring the number of undispersed fibers and calculating according to the following Equation 1 did.

[Equation 1]

Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 Example 22 Example 23 Example 24 acid
(mole%) TPA 100 100 100 100 100 100 100 100 95 98 IPA 0 0 0 0 0 0 0 0 5 2 diol ingredient
(mole%) Formula 1
compound 27 30 32 35 37 40 42 46 30 33 Formula 2 phosphorus
compound One One One One One One One One One One Formula 1+
Formula 2 28 31 33 36 38 41 43 47 31 34 second fiber AA amount
(ppb) 2318 1906 1582 1551 1210 1523 1010 866 2065 1580 water dispersion 0.002 0.003 0.006 0.015 0.024 0.028 0.033 0.112 0.003 0.008

As can be seen from Table 4,

It can be seen that the second fiber provided in the embodiments of the present invention has an acetaldehyde emission of 2400 ppb or less, which is very suitable for wet non-woven fabrics used for interior purposes.

Although one embodiment of the present invention has been described above, the spirit of the present invention is not limited to the embodiments presented herein, and those skilled in the art who understand the spirit of the present invention can add components within the same scope , changes, deletions, additions, etc. may easily suggest other embodiments, but this will also fall within the scope of the present invention.

Claims (10)

a first fiber having a fiber length of 1 to 30 mm; and
An acid component containing terephthalic acid, and an esterified compound in which ethylene glycol and a diol component containing a compound represented by Formula 1 and a compound represented by Formula 2 are reacted are polycondensed and copolyester, A wet non-woven fabric comprising a; a second fiber of 1 to 30 mm.
[Formula 1]

[Formula 2]

According to claim 1,
The total amount of the compound represented by Formula 1 and the compound represented by Formula 2 is 30 to 45 mol% of the diol component. According to claim 1,
The wet nonwoven fabric, characterized in that the content of the compound represented by Formula 1 among the diol components is greater than the content of the compound represented by Formula 2. According to claim 1,
Among the diol components, the compound represented by Formula 1 is 20 to 40 mol%, and the compound represented by Formula 2 is 0.8 to 10 mol%. According to claim 1,
The second fiber is a wet nonwoven fabric, characterized in that the fiber water dispersibility according to the following Equation 1 is 0.040% or less:
[Equation 1]

The number of undispersed fibers is measured by adding 3 g of a second fiber having a moisture content of 25% by weight to 1 liter of water at a temperature of 25° C., stirring it for 10 minutes under the condition of 600 rpm, and leaving it for 1 minute. . According to claim 1,
The first fiber is a wet nonwoven fabric, characterized in that it comprises at least one selected from the group consisting of cellulose fibers, polyester fibers, polyamide fibers and polyolefin fibers. According to claim 1,
The first fiber and the second fiber have a fineness of 1 to 20 denier each independently. According to claim 1,
The second fiber is a wet nonwoven fabric, characterized in that the amount of acetaldehyde (AA) generated according to MS300-55 is 2400ppb or less. A filter member comprising the wet nonwoven fabric according to any one of claims 1 to 8. An interior member comprising the wet nonwoven fabric according to any one of claims 1 to 8.

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