KR20210084090A - Fiber assembly for automobile interior material and automobile interior material comprising the same - Google Patents

Abstract

The present invention relates to a fiber assembly for an automobile interior material. More specifically, the present invention relates to a fiber assembly for an automobile interior material which has excellent texture, sound absorbing coefficient, adhesion strength, elastic repulsion, and processability, minimizes change over time based on excellent heat resistant, and drastically reduces emission of VOCs to be especially suitable for automobiles implementing sealed environments; and an automobile interior material comprising the same. The fiber assembly of the present invention comprises heat adhesion fiber and polyester-based supporting fiber.

Description

Fiber assembly for automobile interior material and automobile interior material comprising the same

The present invention relates to a fiber assembly for interior materials for automobiles, and more particularly, it has excellent touch, sound absorption, adhesive strength and rebound modulus, and minimizes change over time due to excellent heat resistance, and realizes a sealed environment by remarkably reducing the emission of VOCs It relates to a fiber assembly for automobile interior materials particularly suitable for automobiles, and automobile interior materials including the same.

In general, synthetic fibers have a high melting point, which limits their use in many cases. In particular, when it is used as an adhesive to be press-bonded by inserting it between fabrics on a tape or for a purpose such as a wicking in the application of bonding fibers, etc., the textile fabric itself may be deteriorated by heating, and special equipment such as a high-frequency sewing machine must be used. Since there is a cumbersome process, it is desired to easily adhere by a simple ordinary hot press without using such special equipment.

Conventional low-melting polyester fibers have been widely used as hot melt type binder fibers for the purpose of bonding different types of fibers in mutual fiber structures used for manufacturing mattresses, interior materials for automobiles, or various non-woven fabrics.

For example, U.S. Patent No. 4,129,675 discloses a low-melting polyester copolymerized using terephthalic acid (TPA) and isophthalic acid (IPA), and also, Korean Patent Registration No. 10-1216690 No. discloses a low-melting polyester fiber comprising isophthalic acid and diethylene glycol to improve adhesion.

However, the conventional low-melting polyester fiber as described above may have spinnability and adhesiveness above a certain level, but there is a problem in that an interior material for automobiles having a hard feeling is implemented after heat 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 bonding between polyester fibers occurring during the process. In particular, the indoor temperature of a car parked outdoors in summer may rise to 60° C. or higher. Under these conditions, when polyester fibers with poor heat resistance are used, changes in interior materials with time may also be a problem.

On the other hand, automobiles are generally operated in a sealed state from the outside, and in particular, recent trends in driving in a more sealed state due to the influence of fine dust and the like are increasing. Accordingly, the quality of the air in the interior space of a vehicle is important, and there is a report on the emission of volatile organic compounds (VOCs) from interior materials installed in the interior space, and the problem of harming the health of passengers due to the released volatile organic compounds is emerging. the current situation.

Therefore, there is an urgent need to develop a vehicle interior material in which the touch, sound absorption rate, adhesive strength, rebound modulus and workability are improved, the change over time is minimized, and the emission of VOCs is significantly reduced.

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

The present invention has been devised in consideration of the above points, and has excellent feel, sound absorption rate, adhesive strength and workability, minimizes changes over time due to excellent heat resistance, and significantly reduces the emission of VOCs. An object of the present invention is to provide a particularly suitable fiber assembly for automobile interior materials and automobile interior materials including the same.

In order to solve the above problems, the present invention provides an esterified compound in which an acid component containing terephthalic acid, and ethylene glycol, and a diol component containing a compound represented by the following Chemical Formula 1 and Chemical Formula 2 are reacted are polycondensed. a heat-adhesive fiber including a copolyester, and a polyester-based support fiber having a melting point higher than 250°C, wherein the content of the compound represented by Formula 1 among the diol components is represented by Formula 2 To provide a fiber aggregate for automobile interior materials greater than the content of the compound to be used.

[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 substantially.

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 ~ 75 ℃, more preferably 65 ~ 72 ℃.

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

In addition, the heat-adhesive fiber and the support fiber may be included in a weight ratio of 20:80 to 50:50, more preferably 30:70 to 40:60.

In addition, as conditions, (1) 130 N/25 mm ≤ adhesive strength ≤ 200 N/25 mm and (2) 45% ≤ rebound modulus ≤ 60% may be satisfied.

In addition, the heat-adhesive fiber may have a VOCs generation amount of 2600 ppb or less, more preferably 2200 ppb or less, measured according to the US EPA TO-14 method.

In addition, as the sound absorption coefficient according to KS F 2805, (3) at a frequency of 1000 Hz, at a frequency of at least 0.53, (4) at a frequency of 2000 Hz, at least 0.73, (5) at a frequency of 3000 Hz, at a rate of at least 0.83, (6) at a frequency of 4000 Hz The sound absorption coefficient may be 0.92 or more.

In addition, the present invention provides an automobile interior material comprising the fiber assembly for automobile interior material according to the present invention.

The fiber assembly for automobile interior materials according to the present invention is very excellent in feel, sound absorption, adhesive strength, rebound modulus and workability. In addition, it is very suitable for use as an interior material for automobiles where a high indoor temperature is formed during outdoor parking in summer as the change over time is minimized with excellent heat resistance. Furthermore, the emission of VOCs, in particular, the emission of acetaldehyde is significantly reduced, so that it can be widely applied in related fields as it is very suitable for automobile interior materials that are operated in a closed environment.

1 is a schematic cross-sectional view of a heat-adhesive 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.

The fiber assembly for automobile interior materials according to the present invention is an esterified compound in which an acid component containing terephthalic acid, and ethylene glycol, and a diol component containing a compound represented by the following Chemical Formula 1 and Chemical Formula 2 are reacted are polycondensed. It is implemented by including a heat-adhesive fiber containing a copolyester and a polyester-based support fiber having a melting point higher than 250°C.

The heat-adhesive fiber includes an acid component including terephthalic acid, and ethylene glycol and a compound represented by the following Chemical Formula 1 and a compound represented by Chemical Formula 2, wherein the compound represented by Chemical Formula 1 is larger than the compound represented by Chemical Formula 2 A fiber formed including copolyester in which an esterified compound reacted with a diol component provided in the content is polycondensed, and serves to attach the polyester-based support fibers to be described later through thermal fusion, and is a fiber itself It is a fiber that guarantees the shape realization and mechanical strength of the aggregate.

[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 When manufactured as a chip, the drying time can be significantly shortened, and there is an advantage that a synergistic effect can be expressed in reducing the content of VOCs emitted from the heat-adhesive fiber.

If the compound represented by Formula 1 is included 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 spinnability into the heat-adhesive fiber, and on the contrary, the crystallinity may be increased and the heat-adhesive property may be lowered. There are concerns.

The compound represented by Formula 2 further improves the thermal adhesive properties of the copolyester prepared together with the compound represented by Formula 1, and prevents the glass transition temperature of the compound represented by Formula 1 from significantly lowering at 40°C. It is possible to minimize the change over time and improve the storage stability despite the above storage temperature and the vehicle interior temperature rising to 60℃ or higher in summer. In relation to thermal adhesiveness, the compound represented by Formula 2 exhibits appropriate shrinkage properties in the copolyester or heat-adhesive fiber using the same as it is mixed with the compound represented by Formula 1, and thermal adhesion due to the expression of these properties By further increasing the point adhesive force, it is possible to express more elevated thermal adhesive properties.

Preferably, the compound represented by Formula 2 among the diol components 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 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, 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 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, the contractility is significantly expressed, so that it is difficult to process into a fiber aggregate or an interior material.

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 be 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 this case, in the diol component, the compound represented by the above-described formula 1 may be included in a larger content (mol%) than the compound represented by the formula 2. If the compound represented by Formula 1 is included in less or the same amount than 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 is difficult to process into a 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, diethylene glycol generated as a by-product may be included in the sheath formed including the copolyester, and the content of the included diethylene glycol is the copolyester. It may be less than 4% by weight based on the weight of the chip or copolyester alone. 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 long esterification reaction time or a decrease in 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 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]

Since the titanium-based polymerization catalyst represented by Chemical Formula 3 is stable even in the presence of water molecules, it is not deactivated even if it is added before the esterification reaction in which a large amount of water is by-produced, so the esterification reaction and polycondensation reaction within a shorter time than before. The reaction may proceed, thereby suppressing coloring due to yellowing. 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.

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 long esterification reaction time or a decrease in 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. .

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 according to the present invention 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, there may be problems such as not being easy to form a cross-section, and if the intrinsic viscosity exceeds 0.8 dl/g, there may be a problem in spinning due to high pack pressure.

In addition, the copolyester may have a glass transition temperature of 60 ~ 75 ℃, through which it may be more advantageous to achieve the object of the present invention. If the glass transition temperature is less than 60 ℃, the heat-adhesive fiber embodied with copolyester or the embodied article including the same has a large change with time even in temperature conditions exceeding 40 ℃, such as in summer, especially in summer. Considering the interior temperature of the vehicle, the change over time can be significantly increased. 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 limitations of heat treatment required for the drying process after chip formation, the post-processing process after spinning into fibers, etc., there may be a problem in that the process duration is prolonged or the process cannot be smoothly performed.

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-mentioned copolyester can form a heat-adhesive fiber alone. Alternatively, the above-described copolyester may be provided as a sheath 20 surrounding the core 21 as shown in FIG. 1 to form a core sheath type heat-adhesive fiber.

In this case, the core 21 may be a well-known polyester having high heat resistance and mechanical strength compared to the copolyester which is a sheath, and may be, for example, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, etc. It is not limited. The core-sheath heat-adhesive fiber may be, for example, a composite spun of a core and a sheath at a weight ratio of 8:2 to 2:8, but is not limited thereto, and may be spun by appropriately adjusting the ratio according to the purpose. The spinning conditions of the composite fiber, the spinning device and the cooling, stretching, etc. of the composite fiber after spinning can be performed through well-known conditions, devices and processes in the art or by appropriately modifying them, so the present invention relates to this It is not particularly limited. In addition, as an example, the composite fiber may be spun at a spinning temperature of 270 to 290° C., and may be stretched 2.5 to 4.0 times after spinning.

Meanwhile, the heat-adhesive fiber may have, for example, a fineness of 1 to 15 denier, and a fiber length of, for example, 1 to 100 mm, but is not limited thereto.

In addition, the heat-adhesive fiber has a VOCs generation amount of 2600 ppb or less, more preferably 2200 ppb or less according to the US EPA TO-14 method, and through this, the amount of harmful components to the human body in a closed environment such as the inside of a car is significantly reduced It can be very useful as a vehicle interior material, and there is an advantage in that the interior material smell can be reduced.

Next, the support fibers provided in the fiber assembly together with the above-described heat-adhesive fibers will be described.

The support fiber is implemented by including a polyester-based component for compatibility with the heat-adhesive fiber, and serves to guarantee the mechanical strength, shape maintenance, and heat resistance of the fiber assembly. To this end, the polyester-based component may be a component having a melting point higher than 250° C., and through this, it may be more advantageous to achieve the object of the present invention.

The support fiber may have, for example, a fineness of 1 to 10 denier, and a fiber length may be, for example, 1 to 100 mm, but is not limited thereto.

The support fiber may be used without limitation in the case of a known polyester-based component having a melting point of more than 250° C., and may be, for example, polyethylene terephthalate, but is not limited thereto.

The above-described heat-adhesive fiber and the support fiber may form a fiber aggregate in a weight ratio of 20:80 to 50:50, and more preferably, may be formed in a weight ratio of 30:70 to 40:60. If the support fiber is provided at a weight exceeding 4 times the weight of the heat-adhesive fiber, there is a problem in that the adhesive properties of the fiber aggregate are not sufficiently expressed, and there may be a problem in that spinning workability may be significantly reduced. In addition, when the support fiber is provided at a weight of less than one time based on the weight of the heat-adhesive fiber, the sound absorption rate, feel, and shape stability of the fiber aggregate are significantly reduced, and there is a risk that workability such as initial openability or carding performance is significantly reduced. There is a problem that it is difficult to commercialize due to poor radioactivity, and there is a concern that a nonwoven fabric or fabric having a hard feeling may be realized after thermal bonding due to the ring structure of the rigid modifier.

The fiber aggregate including the heat-adhesive fiber and the support fiber may be in the form of a known fabric, for example, a woven fabric, a knitted fabric or a nonwoven fabric, and may be, for example, a nonwoven fabric having no directionality based on the fiber length direction. The nonwoven fabric may be manufactured by a known dry or wet nonwoven manufacturing method, and the present invention is not particularly limited thereto.

For example, the heat-adhesive fiber and the support fiber may be manufactured as short fibers having a predetermined length, and then the short fibers may be mixed and opened and then heat-treated to form a fiber aggregate. The heat treatment may be 100 ~ 180 ℃, more preferably 120 ~ 180 ℃, through which it is possible to express more improved adhesive properties.

The fiber assembly for automobile interior materials according to an embodiment of the present invention may satisfy condition (1) 130 N/25mm ≤ adhesive strength ≤ 200 N/25mm and condition (2) 45% ≤ rebound modulus ≤ 60%, This makes them more suitable for automotive interiors, especially floor carpets.

In addition, under condition (3), the sound absorption coefficient at a frequency of 1000 Hz may be 0.53 or more, more preferably 0.53 to 0.75. In addition, in (4) at a frequency of 2000 Hz, a sound absorption coefficient of 0.73 or more, more preferably 0.73 to 0.85. In addition, the condition (5) may be a sound absorption coefficient of 0.83 or more at a frequency of 3000 Hz, more preferably 0.83 to 0.95, and as the condition (6), a sound absorption coefficient of 0.92 or more at a frequency of 4000 Hz, more preferably 0.92 to 0.99. As such a sound absorption rate is satisfied, when used as an interior material for a vehicle, it can be advantageous for creating a quiet interior environment of the vehicle by maximally preventing noise from outside the vehicle and noise generated from the vehicle itself from being transmitted to the interior.

On the other hand, the above-mentioned fiber aggregate for automobile interior materials may be implemented as automobile interior materials by further including single or regenerated denim, melt-blown nonwoven fabric, and the like. The automobile interior material may be a known type of interior material, and preferably, it may be particularly suitable for flow carpets, trunk mats, dashboards, etc. in consideration of excellent sound absorption coefficient, adhesive strength, heat resistance and low VOCs emission.

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, 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. did.

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 chip and the PET chip are placed in a hopper, respectively. After input, melted and put into a core-sheath spinneret, respectively, and then composite spun so that the core and the sheath part at a spinning speed of 1000mpm under 275°C in a weight ratio of 5:5, and stretched 3.0 times to obtain a fiber length of 51 mm and a fineness of 4.0de. A core-sheath type heat-adhesive composite fiber as shown in Table 1 was prepared.

[Formula 1]

[Formula 2]

[Formula 3]

The prepared core-sheath composite fiber and polyethylene terephthalate (PET) short fiber (fiber length 51 mm, fineness 4.0de) were mixed and fiberd at a ratio of 5: 5, and then heat treated at a temperature of 120°C, 140°C and 160°C, respectively. A total of three types of fiber aggregates with a basis weight of 35 g/m2 were realized.

<Examples 2 to 14>

It was prepared in the same manner as in Example 1, but by changing the composition ratio of the monomer 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 was manufactured and a fiber aggregate was implemented using this.

<Comparative Examples 1 to 4>

It was prepared in the same manner as in Example 1, but by changing the composition of the monomer for preparing the copolyester as shown in Table 2 below, polyester chips and core-sheath composite fibers using the same were prepared as shown in Table 2 below, and fiber aggregates using the same has been implemented.

<Experimental Example 1>

The following physical properties were evaluated for the copolyester chip or core-sheath type heat-adhesive composite fiber, which is an intermediate during the manufacture of three types of fiber aggregates or fiber aggregates implemented according to Examples and Comparative Examples, and the results are shown in Tables 1 to Table 3 shows.

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

Spinning workability occurs during spinning processing for core-sheath composite fibers spun at the same content in Examples and Comparative Examples (meaning a lump formed by partially fusion of the fiber strands passing through the slit or irregular fusion of the strands after trimming) The number was counted through a drip detector, and the number of drips generated in the remaining preparation examples and comparative preparation examples was expressed as a relative percentage based on the drip occurrence value in Preparation 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 (×).

As can be seen through 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 confirmed that the shape is deformed (Comparative Example 4) in the evaluation of the 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 confirmed that it is not suitable for

<Examples 15 to 29>

It was prepared in the same manner as in Example 1, except that the composition ratio of the monomers for preparing the copolyester was changed as shown in Table 4 to prepare a copolyester, and a fiber assembly as shown in Table 4 was prepared using this. At this time, the heat treatment temperature for producing the fiber assembly was set to 140 ℃.

<Comparative Example 5>

It was prepared in the same manner as in Example 1, except that the composition ratio of the monomers for preparing the copolyester was changed as shown in Table 4 to prepare a copolyester, and a fiber assembly as shown in Table 4 was prepared using this. At this time, the heat treatment temperature for producing the fiber assembly was set to 140 ℃.

<Experimental Example 2>

The following physical properties were evaluated for the copolyester chip as an intermediate during the manufacture of the heat-adhesive fibers, fiber aggregates or fiber aggregates implemented according to Examples 15 to 29 and Comparative Example 5, and the results are shown in Table 4 below.

1. Intrinsic Viscosity

Intrinsic viscosity was measured in the same manner as in Experimental Example 1.

2. Volatile organic compounds (VOCs) content

The heat-adhesive fibers were measured according to the US EPA TO-14 Method.

3. Soft touch

The tactile feel was evaluated in the same manner as in Experimental Example 1.

As can be seen from Table 4,

In the case of Examples 15 to 29, compared to Comparative Example 5, the amount of VOCs generated by the heat-adhesive fiber was small, so it can be seen that the fiber aggregate having the same is suitable for use in automobile interior materials.

<Examples 30 to 34>

It was prepared in the same manner as in Example 21, except that the mixing ratio of the heat-adhesive fiber and the PET support fiber was changed as shown in Table 5 below to prepare a fiber aggregate. At this time, the heat treatment temperature for producing the fiber assembly was 165 ℃.

<Comparative Examples 6 to 7>

It was prepared in the same manner as in Example 21, except that the composition of the heat-adhesive fiber and the mixing ratio of the PET fiber were changed as shown in Table 5 below to prepare a fiber aggregate. At this time, the heat treatment temperature for producing the fiber assembly was 165 ℃.

<Experimental Example 3>

The following physical properties were evaluated for the fiber aggregates according to Example 21, Examples 30 to 34, and Comparative Examples 6 to 8, and are shown in Table 5 below.

1. Adhesive strength

It was evaluated in the same manner as in Experimental Example 1.

2. Rebound modulus

Dropping an iron bead from a constant height to the sea perm piece and measuring the repulsion and bouncing height (JIS K-6301, unit: %). The test piece was made in a square shape with a side length of 50 mm or more and a thickness of 50 mm or more, and a steel ball weighing 16 g and a diameter of 16 mm was dropped from a height of 500 mm to the test piece to measure the maximum rebound height, and then three test pieces The rebound value was measured at least 3 times continuously within 1 minute in each, and the median value was determined as the rebound modulus (%).

3. Sound Absorption Coefficient

It was measured according to KS F 2805.

As can be seen from Table 5,

It can be confirmed that the fiber aggregate according to the embodiment of the present invention is suitable for interior materials of automobiles because it has excellent adhesive strength and rebound modulus and also excellent sound absorption coefficient compared to the fiber aggregate according to the comparative example.

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 (11)

Thermo-adhesive comprising copolyester in which an acid component containing terephthalic acid, and ethylene glycol, and a diol component including a compound represented by the following formula (1) and a compound represented by the following formula (2) are reacted are polycondensed fiber; and a polyester-based support fiber having a melting point higher than 250° C.;
In the copolyester, 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, a fiber aggregate for interior materials for automobiles.
[Formula 1]

[Formula 2]

According to claim 1,
The fiber assembly for automobile interior materials, characterized in that the diol component does not contain diethylene glycol.
According to claim 1,
The total content 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 fiber assembly for automobile interior materials, 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,
Among the diol components, the compound represented by Formula 1 is 30 to 40 mol%, and the compound represented by Formula 2 is 0.8 to 6 mol%.
According to claim 1,
A fiber assembly for automobile interior materials, characterized in that it satisfies the following conditions.
(1) 130 N/25㎜ ≤ Adhesive strength ≤ 200 N/25㎜
(2) 45% ≤ Rebound modulus < 60%
According to claim 1,
The heat-adhesive fiber is a fiber assembly for automobile interior materials, characterized in that the amount of VOCs generated according to the US EPA TO-14 method is 2600 ppb or less.
According to claim 1,
A fiber assembly for interior materials for automobiles, characterized in that the sound absorption rate according to KS F 2805 satisfies the following conditions.
(3) At a frequency of 1000 Hz, a sound absorption coefficient of 0.53 or more
(4) At a frequency of 2000 Hz, a sound absorption coefficient of 0.73 or more
According to claim 1,
A fiber assembly for interior materials for automobiles, characterized in that the sound absorption rate according to KS F 2805 satisfies the following conditions.
(5) A sound absorption coefficient of 0.83 or more at a frequency of 3000 Hz
(6) At a frequency of 4000 Hz, a sound absorption coefficient of 0.92 or more
An automobile interior material comprising the fiber assembly for automobile interior material according to any one of claims 1 to 10.

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