JPH07189101A - Soundproof material for automobile - Google Patents

Abstract

PURPOSE:To obtain a soundproof material for automobiles comprising nonwoven fabric having soft handle, hardly yielding after use for a long period of time or in a high-temperature atmosphere, having excellent heat distortion resistance. CONSTITUTION:This soundproof material for automobiles is obtained by bonding a polyethylene terephthalate fiber as a main component with a core (polyethylene terephthalate)/sheath (a copolyester of a polyethylene terephthalate.polybutylene terephthalate having >=100 deg.C melting point of crystal and a poly epsiloncaprolactone) conjugated polyester-based binder fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soundproof material for automobiles. More specifically, the present invention relates to a soundproof material for automobiles, which is used as a ceiling material, a floor material, a trunk room interior material, or the like, and is made of a thermoformed nonwoven fabric.

[0002]

2. Description of the Related Art Conventionally, a molded ceiling is often used as a ceiling material for automobiles. This is one in which a base material made of a woven fabric, a knitted fabric or a thin non-woven fabric is integrated with a base material, and is used by being fitted into a fixed pedestal on the ceiling. As the base material, urethane foam, polyolefin or corrugated cardboard reinforced with glass fiber has been used. In addition, anti-wool resin felt has been used as the floor material and the interior material of the trunk room. Further, in recent years, it has been proposed to use a non-woven fabric composed mainly of a non-woven fabric composed mainly of synthetic fibers with a binder fiber or the like as a molded ceiling or floor material for the purpose of weight reduction, sound absorption, sound insulation and improvement of heat insulation. (JP-A-5-156560, JP-A-5-186947)

[0003]

The conventional non-woven fabric formed by thermoforming a combination of a main fiber and a binder fiber has insufficient adhesive strength and is easily deformed when a load is applied, or the door is exposed to direct sunlight in summer. 70 to 80 when closed
When used in a high temperature atmosphere such as ℃, it has the drawback of causing deformation.

The present invention solves the drawbacks such as the insufficient adhesive strength of the conventional non-woven fabric using the binder fiber and the ease of deformation when used in a high temperature atmosphere, and the ceiling material,
It is an object of the present invention to provide a soundproof material for automobiles, which is used as a floor material, a trunk room interior material, or the like and is made of a thermoformed nonwoven fabric.

[0005]

The present inventor has arrived at the present invention as a result of extensive studies to develop such a novel nonwoven fabric. That is, the present invention provides a soundproofing material for automobiles, characterized in that the main fiber is point-bonded with ε-caprolactone copolymerized polyester binder fiber having a crystal melting point of 100 ° C. or higher and thermoformed into an arbitrary shape. To do.

The present invention will be described in detail below. First, the main fiber may be synthetic fiber such as polyester fiber, nylon fiber, acrylic fiber, polypropylene fiber or the like, semi-synthetic fiber such as rayon fiber, or natural fiber such as wool, cotton or hemp. Among them, polyester fibers such as ethylene terephthalate units, butylene terephthalate units or ethylene naphthalate,
In particular, those having an ethylene-2,6-naphthalate unit as a main constituent component are preferable, but polyethylene terephthalate fibers are particularly preferable from the viewpoints of physical properties such as sound absorbing property, sound insulating property and difficulty of deformation and economical efficiency. It should be noted that a polyester obtained by copolymerizing other components such as isophthalic acid, 5-sulfoisophthalic acid, and diethylene glycol may be used as long as the characteristics are not impaired. Further, the cross-sectional shape of the polyester fiber may be a round cross section or an irregular cross section, and may be hollow or non-hollow. Further, the fineness is not particularly limited and may be determined according to the required characteristics depending on the application, but generally 2 to 200
Denier ones are used. The crimp form is not particularly limited, but a one having a conjugate type three-dimensional crimp is more preferable because a sound absorbing and sound insulating property can be obtained. The polyester fiber may be added with an ordinary padding oil agent or may be added with a particularly slippery silicone or non-silicone slippery oil agent.

The polyester binder fiber, which is another component of the automobile soundproofing material of the present invention, has a melting point of 1
It has ε-caprolactone copolymerized polyester of 00 ° C. or higher as a binder component. This copolymerized polyester is a copolymer of ethylene terephthalate and / or butylene terephthalate with ε-caprolactone, and has 3 to 80 mol% ε of ethylene terephthalate units and / or butylene terephthalate units.
-Copolymers of caprolactone units are preferred. Further, it may be copolymerized with isophthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, ethylene glycol, 1,6-hexanediol or the like. In this case, the total sum of the components to be copolymerized other than ε-caprolactone is preferably about 20 mol% or less based on the number of moles of the constituent components of the polyester. Further, the ε-caprolactone unit in the polyester may be random copolymerized or block copolymerized with other constitutional units.

When the copolymerized ε-caprolactone unit is less than 3 mol%, the adhesive strength is insufficient and the nonwoven fabric is likely to be deformed when a load is applied. Further, when the ε-caprolactone unit is 40 mol% or more, the obtained polyester becomes elastomeric and the surface of the obtained non-woven fabric exhibits a unique and extremely soft texture. When the ε-caprolactone unit exceeds 80 mol%, the melting point of the obtained polyester becomes too low, and a problem in the processing step tends to occur, or the polyester tends to be deformed when used in a high temperature atmosphere.

The polyester binder fiber has a melting point of 10
It is 0 ° C or higher, preferably 130 ° C or higher. Melting point 10
When the temperature is lower than 0 ° C., it is not preferable because it is easily deformed when used under the condition of being exposed to a high temperature atmosphere, for example, under the hot sun. The upper limit of the melting point is preferably lower than the melting point or decomposition point of the main fiber by 20 ° C. or more.

As the polyester binder fiber,
A single-component fiber consisting only of a polyester binder component, and a core-sheath type, a side-by-side type, a sea-island type, a split fiber type, etc. in which the polyester binder component forms all or part of the surface of the single fiber, and the like. To be
Among these, the core-sheath type core is polyethylene terephthalate, the sheath is a composite fiber of polyester binder component, the softness of the texture of the nonwoven fabric surface, and the high adhesive strength, that is, the shape retention when the nonwoven fabric and It is preferable from the viewpoint of the strength of the nonwoven fabric. Although the fineness of the polyester binder fiber is not particularly limited, it is 2-100
Denier is suitable.

The proportion of the polyester binder fiber used in the present invention is appropriately 5 to 70% by weight based on the total weight of the non-woven fabric, but it can be changed according to the characteristics required by the application. The nonwoven fabric of the present invention, for example, when the main fiber is a polyester fiber, is crimped 5 to 100 mm,
Preferably, the main polyester fibers cut into 20 to 80 mm and the polyester binder fibers are mixed at a ratio determined by the use or the required characteristics, a web is formed with a carding machine, etc., and then the polyester is passed through a heat treatment device. It can be obtained by melting the system binder fiber and spot joining the polyester fiber.
In this case, the needling process may be performed before the heat treatment. As the heat treatment apparatus, a hot air circulation dryer, a hot air once-through dryer, a saxion drum dryer, a Yankee drum dryer, or the like is used, and the treatment may be performed by selecting the treatment temperature and the treatment time according to the melting point of the polyester elastomer.

The nonwoven fabric of the present invention preferably has a thickness of 5 mm or more in order to maintain its soundproofing and soundproofing properties.
The upper limit of the thickness is preferably about 150 mm from the viewpoint of manufacturing equipment, manufacturing cost, and ease of use. Further, the density of the nonwoven fabric of the present invention is preferably 0.010 g / cm ³ or more. If the density is less than 0.010 g / cm ^3, it may be easily set by repeated compression. The upper limit of density is
Not specified because it depends on the performance requirements of the non-woven fabric depending on the application, but 0.2 g from the viewpoint of manufacturing equipment, manufacturing cost, etc.
/ Cm ³ or less is preferable. In order to control the thickness and density of the nonwoven fabric of the present invention, while appropriately selecting the basis weight of the web before heat treatment in consideration of the area shrinkage of the web by heat treatment, incorporating a thickness control roll in the heat treatment device,
A web may be sandwiched between plates or wire mesh sandwiching a spacer having a predetermined thickness for heat treatment.

[0013]

In the non-woven fabric of the present invention, the main fibers are relatively soft, are not easily thermally decomposed, and are point-joined with a polyester binder which is easily heat-welded. Therefore, the obtained non-woven fabric has a soft texture and is repeatedly compressed. Even if the spot-bonded parts have a high adhesive strength, the bonded parts are difficult to peel off. Therefore, the morphology of the non-woven fabric is maintained well, and it is hard to set. Further, since this binder component is an ε-caprolactone copolymerized polyester polymer having a melting point of 100 ° C. or higher, it is difficult to deform and hard to be deformed even in a high temperature atmosphere of, for example, 70 to 80 ° C. during use.

[0014]

The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto. The evaluation methods for various physical properties described in the examples are as follows. (1) Relative viscosity Using an equal weight mixture of phenol and ethane tetrachloride as a solvent,
It was measured at a sample concentration of 0.5 g / dl and a temperature of 20 ° C. (2) Melting point Using a differential scanning calorimeter DSC-2 type manufactured by Perkin Elmer, the melting point was measured at a temperature rising rate of 20 ° C / min.

(3) Settling resistance during repeated compression After measuring the thickness of the nonwoven fabric, a test piece (10 cm × 10 cm)
Was sandwiched between parallel flat plates, and the thickness was measured after a repeated compression test of a total of 50,000 times with a load of 15 kg at 60 times per minute, and the bulkiness retention rate C (%) was calculated by the following formula 1. Calculate,
It was used as a measure of fatigue. The larger the value of C, the less likely it is to get tired.

[0016]

[Equation 1]

(4) Heat-deformation resistance Heat-molded non-woven fabric of 20 cm
Place it in the center of a square formwork that is horizontally placed at 20 cm
Place a weight of 200g on the center of the non-woven fabric, 110 ℃, 6
It was left to stand in a hot atmosphere for 0 minutes. Then, after cooling to room temperature and removing the weight, the degree of sag of the original shape of the nonwoven fabric on which the weight was placed was measured and used as a measure of heat distortion resistance. The smaller the value, the more difficult it is to deform.

(5) Feeling The feel of the surface of the non-woven fabric was evaluated by the following three grades by a sensory test by 10 panelists. 1: Soft 2: Normal 3: Hard

Example 1 Ethylene terephthalate unit / butylene terephthalate unit (molar ratio 1/1) and 20 mol% of ε-CL based on the total number of moles of this alkylene terephthalate unit and ε-caprolactone (ε-CL). Random copolymerized polyester chip (relative viscosity 1.34, melting point 144 ° C.) as a binder component obtained by the above, and relative viscosity 1.38.
After drying the polyethylene terephthalate (PET) chip under reduced pressure using a conventional composite melt spinning apparatus, the random copolymerized polyester is placed in the sheath portion and PET is placed in the core portion to obtain a composite ratio (weight ratio). Was 1: 1, the spinning temperature was 280 ° C., and the total discharge rate was 313 g / min. The spun yarn was cooled and then taken off at a take-off speed of 1000 m / min to obtain an undrawn fiber yarn. The obtained yarns were bundled, made into a tow of 100,000 denier, drawn at a draw ratio of 2.9, a draw temperature of 60 ° C, heat-treated with a heat drum at 120 ° C, and then wound using a push-in crimper. After crimping, it was cut into a length of 51 mm to obtain a core-sheath type composite polyester binder fiber having a single yarn fineness of 4 denier.

Obtained binder fiber and PE having a hollow cross section
T fiber (strength 4.0 g / d, elongation 58%, fineness 6 denier, cut length 51 mm, hollow ratio <hollow portion of fiber cross section> 27%) was mixed at a weight ratio of 20:80 and carded. After passing through the machine, stack with a cross-lapper and have a basis weight of 600
Needling was performed at a needle density of 240 needles / cm ² through a needle locker room having a barbed needle having a g / m ² web. Further, this web is put between wire nets having a spacer of 20 mm in thickness between them, and the thickness is regulated, and heat treatment is performed for 5 minutes in a hot air circulation dryer at 200 ° C. to obtain a thickness of 20 mm and a density of 0.03 g / A non-woven fabric of Example 1 having cm ³ was obtained. The polyester binder component did not appear to be thermally decomposed, and it was white and had a soft texture.

Example 2 Polybutylene terephthalate (PBT) was used in place of the random copolyester chip used in Example 1.
And a random copolymerized polyester chip (relative viscosity 1.34, melting point 182 ° C.) as a binder component obtained by blending 20 mol% of ε-CL with respect to the total number of moles of C., and the nonwoven fabric of Example 2 was obtained in the same manner as in Example 1 except that the temperature for heat treatment of the nonwoven fabric was 190.degree.

Example 3 The random copolymer polyester chip used in Example 1 was replaced by ε-based on the total number of moles of PET and ε-CL.
A random copolymerized polyester chip (relative viscosity 1.42, melting point 196 ° C.) obtained by blending 28 mol% of CL was used, except that the heat-drum heat treatment was 150 ° C. and the nonwoven fabric heat treatment temperature was 210 ° C. A nonwoven fabric of Example 3 was obtained in the same manner as in 1. It was not observed that the polyester binder component was thermally decomposed even though the heat treatment temperature was high.

Example 4 Instead of the random copolyester chip used in Example 1, ε-based on the total number of moles of PET and ε-CL.
Random copolymerized polyester elastomer chip obtained by blending 60 mol% of CL (relative viscosity 1.82, melting point 18
3 ° C.), the heat drum heat treatment was 120 ° C., and the heat treatment temperature of the nonwoven fabric was 190 ° C., except that the nonwoven fabric of Example 4 was obtained in the same manner as in Example 1. It was not observed that the polyester elastomer component was thermally decomposed despite the high heat treatment temperature.

Example 5 Instead of the random copolyester chip used in Example 1, ε-based on the total number of moles of PBT and ε-CL.
A random copolymer polyester elastomer chip obtained by blending 62 mol% of CL (relative viscosity 1.95, melting point 16
0 ° C.), the heat drum heat treatment was 110 ° C., and the heat treatment temperature of the nonwoven fabric was 180 ° C., and a nonwoven fabric of Example 5 was obtained in the same manner as in Example 1.

Example 6 A random copolymer polyester elastomer chip (relative viscosity 2.05, melting point, obtained by blending 71 mol% ε-CL with PBT, instead of the random copolymer polyester chip used in Example 1) 133 ° C.), heat drum heat treatment at 100 ° C., nonwoven fabric heat treatment temperature at 150 ° C.
A nonwoven fabric of Example 6 was obtained in the same manner as in Example 1 except that the temperature was changed to ° C.

Example 7 A random copolymer polyester elastomer chip (relative viscosity 2.08, melting point, obtained by blending 53 mol% of ε-CL with PBT, instead of the random copolymer polyester chip used in Example 1) 180 ° C.), heat drum heat treatment at 120 ° C., nonwoven fabric heat treatment temperature at 200 ° C.
A nonwoven fabric of Example 7 was obtained in the same manner as in Example 1 except that the temperature was changed to 0 ° C. It was not observed that the polyester elastomer component was thermally decomposed despite the high heat treatment temperature.

Example 8 A non-woven fabric of Example 8 was prepared in the same manner as in Example 1 except that the basis weight was 800 g / cm ² , the thickness of the non-woven fabric was 10 mm, and the same density was 0.08 g / cm ^2. Got

Comparative Example 1 Instead of the random copolyester chip used in Example 1, 28 mol% of ethylene terephthalate unit / butylene terephthalate unit (molar ratio 6/4), ε-
A polyester elastomer chip (relative viscosity: 1.92, melting point: 94 ° C) obtained by blending CL in an amount of 72 mol% was used, and after stretching, heat treatment was performed at a heat drum at 60 ° C instead of heat treatment at a heat drum at 140 ° C. It was carried out under the conditions.
Although a considerable amount of stretching roller winding and close contact between fibers were observed, a small amount of sample was obtained. Using this as a binder fiber, change the heat treatment temperature of the web to 180 ℃ and change it to 120 ℃.
A nonwoven fabric of Comparative Example 1 was obtained in the same manner as in Example 1 except that the above was adopted.

Comparative Example 2 Instead of the random copolymerized polyester chip used in Example 1, a polyester chip comprising ethylene terephthalate units / ethylene isophthalate units (molar ratio 6/4) (relative viscosity 1.37, melting point by DSC) 1) after stretching using a visual softening point of 110 ° C)
The heat treatment was carried out without heat treatment in place of heat treatment at a heat drum at 40 ° C. Use this as binder fiber and change the heat treatment temperature of the web to 180 ℃
A nonwoven fabric of Comparative Example 2 was obtained in the same manner as in Example 1 except that the above was adopted. Table 1 shows the evaluation results of the texture, the sag resistance, and the heat distortion resistance of the nonwoven fabrics of Examples 1 to 8 and Comparative Examples 1 and 2.

[0030]

[Table 1]

As is clear from Table 1, all of the non-woven fabrics of Examples 1 to 8 were good in feeling, settling resistance and heat distortion resistance, but the non-woven fabric of Comparative Example 1 was used as an adhesive component. Since the polyester elastomer has a low melting point, it was inferior in heat distortion resistance. Further, the nonwoven fabric of Comparative Example 2 had a hard texture and was easily set in a high temperature atmosphere.

[0032]

EFFECT OF THE INVENTION The nonwoven fabric of the present invention has a soft texture, and is unlikely to sag under repeated compression or a load under a high temperature atmosphere. Therefore, when used as a soundproofing material for automobiles, for example, as a ceiling material, a flooring material, or a trunk room interior material, it is possible to achieve a reduction in weight and at the same time have excellent soundproofing and soundproofing properties. In addition, it is excellent in that it is not easily settled or deformed even after use or in a high temperature atmosphere. Further, the heat fusion processability is good.

Claims (1)

[Claims] 1. A soundproofing material for automobiles, characterized in that the main fiber is point-bonded with ε-caprolactone copolymerized polyester binder fiber having a crystal melting point of 100 ° C. or higher and thermoformed into an arbitrary shape.