TWI616329B - Polyvinyl butyral fiber and fiber assembly containing same - Google Patents

Abstract

Polyvinyl butyral with a degree of butyralization of 50 to 90% by mass, an MFR at 150 ° C, 2.16 kgf of 0.5 to 45 g / 10 minutes, and an acid value of 0.2 mg KOH / g or less A pellet made of polyvinyl butyral is melt-spun at a temperature lower than 240 ° C to obtain a polyvinyl butyral-containing fiber having a butyraldehyde content of 20 mass ppm or less. This makes it possible to obtain polyvinyl butyral fibers having a characteristic odor which is suppressed during processing, and to provide a laminated body which is applied to interior materials using a woven or non-woven fabric containing the fibers as an adhesive layer.

Description

Polyvinyl butyral fibers and fiber aggregates containing the same

The present invention relates to polyvinyl butyral (hereinafter referred to as PVB) fibers and a method for producing the same. The present invention relates to a fiber assembly containing the PVB fibers. Furthermore, it relates to a laminated body formed by adhering a plurality of layers through an adhesive layer including the fiber assembly, and an interior material including the laminated body.

PVB is excellent in adhesiveness and compatibility with various materials and solubility in organic solvents. It is widely used as a ceramic adhesive, adhesive, ink, coating, and interlayer film for laminated glass. In recent years, it has also been proposed to use it as a fiber. For example, in Patent Document 1, it is described that a non-woven fabric including PVB is used as a bonding layer, thereby obtaining a multilayer structure having excellent mechanical properties and sound absorption. However, the PVB fiber has a problem of so-called odor generated during processing.

A method for suppressing odor generation of PVB pellets is described in Patent Document 2. Patent Document 2 describes a method for producing polyvinyl butyral resin particles, which includes a step of melting a polyvinyl butyral resin powder having a moisture content of 0.01 to 6% by weight using a melt extruder, wherein The melt extruder is used to remove the volatile part And a step of cutting off the molten material of the polyvinyl butyral resin by the above-mentioned melting extruder using the above-mentioned melting extruder. According to this method, polyvinyl butyral resin particles can be obtained with almost no odor during production and processing. The total content of butyraldehyde and 2-ethyl-2-hexenal in the resin particles is 100 ppm by weight or less. The acid value of the resin particles is 0.7 mgKOH / g or less. In Example 1 of Patent Document 2, granules having a butyraldehyde content of 16 weight ppm and an acid value of 0.20 mgKOH / g are described. In Patent Document 2, although the solubility of the obtained PVB resin particles in an organic solvent is evaluated, there is no description about the melt-molding of the PVB resin particles, nor is there any description about the odor after the melt-molding.

[Prior technical literature] [Patent Literature]

[Patent Document 1] WO2006 / 101175

[Patent Document 2] WO2008 / 123150

The present invention has been made in order to solve the above-mentioned problems, and an object thereof is to provide a PVB fiber capable of suppressing a peculiar odor generated during processing and a method for producing the same. The object is also to provide a fiber assembly containing the PVB fiber and its use.

The above problem is provided by including a degree of butyralization of 50 to 90% by mass and a butyral content of 20% by mass. It is solved by the polyvinyl butyral fibers below ppm. The preferred embodiment of the fiber is a single fiber composed only of polyvinyl butyral, a composite fiber composed of polyvinyl butyral as one of the components, or a component of polyvinyl butyral as a component A blend of fibers. In addition, a fiber assembly containing the fiber is also a preferred embodiment, and among them, a non-woven fabric, a woven fabric, paper, or a knitted fabric is preferable.

A plurality of layers are formed through an adhesive layer containing the aforementioned fiber assembly The subsequent laminated body is a preferred embodiment. In this case, it is preferable that the inorganic fiber layer and the other layers are bonded via the aforementioned bonding layer, and the inorganic fiber layer is more preferably a glass fiber layer. At this time, a laminated body in which the inorganic fiber layer, the foam layer, and the surface material layer are bonded via the aforementioned bonding layer is also a preferred embodiment. The aforementioned laminated body is preferably used as a material for interior.

Also, the above problems are solved by providing a manufacturing method of the fiber. The solution, the manufacturing method of the fiber is characterized by using a butyralization degree of 50 to 90% by mass, an MFR of 2.16 kgf at 150 ° C of 0.5 to 45 g / 10 minutes, and an acid value of 0.2 mg KOH / g or less The particles made of polyvinyl butyral are melt-spun at a temperature below 240 ° C.

In this case, use a butyraldehyde content of 10 mass ppm or less. The pellets are preferably melt-spun. In addition, the polyvinyl butyral powder having a moisture content of 5 mass% or less is also put into the extruder, and the pressure is reduced to less than 0.008 MPa using at least one exhaust port to remove the volatile portion, and at It is preferable to perform melt-kneading at a temperature to obtain pellets, and then perform melt-spinning using the pellets.

In the aforementioned manufacturing method, the aforementioned fiber is a long fiber In some cases, the winding speed during melt spinning is preferably 2000 to 5000 meters / minute. At this time, after the melt-spun fiber is temporarily cooled to a temperature below the glass transition point, it is further heated and stretched as it is, and then an oil agent is added and then wound up. When the melt-spun fiber is temporarily cooled to a temperature below the glass transition point, it is preferable to blow a cooling air having a temperature of 20 to 30 ° C and a relative humidity of 20 to 60% at a speed of 0.4 to 1.0 m / s. Better.

The PVB fibers of the present invention are suppressed from peculiar odor generated during processing, and are suitable for use with various fiber aggregates. By using the fiber assembly, the heat bonding step when manufacturing the laminated body can be simplified, and the bonding can be performed even under low pressure / low temperature conditions, which also contributes to energy saving. Furthermore, the generation of malodor during the heat-bonding step can be suppressed. The laminated body thus obtained can be used as an interior material because it can secure the thickness of the structure, and has excellent rigidity, sound absorption, and heat distortion resistance.

1‧‧‧ foam layer

2, 3‧‧‧ glass fiber layer

4, 5‧‧‧ surface material layer

6‧‧‧ Adjacent layer

10‧‧‧ Interior materials

FIG. 1 is a cross-sectional view showing an example of a vehicle interior material.

[Form of Implementing Invention]

Hereinafter, the present invention will be described in detail. The PVB used in the present invention is one represented by the following chemical formula (I).

In the PVB used in the present invention, the degree of butyralization is shown in the table. The content ratio of the repeating unit X in the polymer composition represented by the said chemical formula (I) is shown. In the present invention, specifically, the degree of butyralization is preferably 50 to 90% by mass, and more preferably 55 to 85% by mass. When the degree of butyralization is less than 50% by mass, the glass transition temperature becomes high, the fluidity of the resin becomes poor, and the thermal adhesiveness becomes low. On the other hand, if the butyralization degree exceeds 90% by mass, the strength of the resin at the interface is lowered, and the rigidity is lowered when it is formed into a laminated body. The degree of butyralization did not change substantially between the PVB particles of the raw material and the PVB fibers after melt spinning.

The manufacturing method of the PVB resin used in the present invention is not It is specifically limited, and a well-known method can be used. For example, the polyvinyl ester obtained by polymerizing a vinyl ester monomer is saponified to obtain polyvinyl alcohol, and by butyralizing the polyvinyl ester, a PVB resin can be obtained. Hereinafter, a typical production method of PVB resin will be described.

Polyvinyl alcohol can be obtained, for example, by polymerizing vinyl ester monomers. The obtained polyvinyl ester is obtained by saponification. As a method for polymerizing a vinyl ester monomer, a known method such as a solution polymerization method, a block polymerization method, a suspension polymerization method, and an emulsion polymerization method can be suitably used. In this case, the polymerization initiator may be appropriately selected in accordance with the polymerization method from an azo-based initiator, a peroxide-based initiator, a redox-based initiator, and the like.

For vinyl ester monomers, for example, vinyl formate can be used , Vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, trimethyl vinyl acetate, vinyl versatate, vinyl hexanoate, vinyl octoate, vinyl laurate , Vinyl palmitate, vinyl stearate, vinyl oleate, vinyl benzoate, etc. may be used, and among them, vinyl acetate is preferred. When the above vinyl ester monomer is polymerized, it can be copolymerized with other monomers within a range not detrimental to the gist of the present invention.

As the method of saponification, a well-known method, that is, a method of alcohol decomposition by an alkali catalyst or an acid catalyst, a method of hydrolysis, etc., in which caustic soda (NaOH) is used due to the use of methanol as a solvent The method as a catalyst is simple, so it is preferable. The polyvinyl alcohol obtained by saponifying a polyvinyl ester obtained by polymerizing a vinyl ester monomer includes a vinyl alcohol unit and a vinyl ester unit. For example, in the case where vinyl acetate is used as the vinyl ester monomer, the polyvinyl alcohol obtained by the above-mentioned production method includes a vinyl alcohol unit and a vinyl acetate unit.

The butyralization of polyvinyl alcohol may be performed according to a known method. For example, polyvinyl alcohol and n-butyraldehyde (hereinafter, simply referred to as butyraldehyde) may be mixed in the presence of an acid catalyst. The acid catalyst is not particularly limited, and any organic acid or inorganic acid may be used. For example, acetic acid, p-toluenesulfonic acid, nitric acid, sulfuric acid, and hydrochloric acid may be used. Among them, a method using hydrochloric acid, sulfuric acid, and nitric acid is a general method, and hydrochloric acid is particularly preferable.

A specific method for producing a PVB resin is exemplified by the following method. First, an aqueous solution of polyvinyl alcohol (concentration: 3 to 15% by mass) was prepared at 80 to 100 ° C, and the solution was allowed to stand for 10 to 60 minutes. The temperature of the aqueous solution is slowly reduced to -10 ~ 30 ° C. Then, butyraldehyde and an acid catalyst are added to the aqueous solution, and the butyralization reaction is performed for 30 to 300 minutes while maintaining the temperature at -10 to 30 ° C, and then the temperature is further increased to 30 to 80 ° C over 30 to 200 minutes. Keep in this temperature range for 1 ~ 8 hours. Next, a neutralization treatment with an alkali, washing with water, and drying are performed to obtain a powder of polyvinyl butyral.

The PVB powder obtained in this way can be dissolved in Among solvents, it is used in ceramic adhesives, adhesives, inks, coatings, and the like. Moreover, by adding a plasticizer and kneading it, an interlayer film for laminated glass can also be obtained. However, depending on the application, the powder may sometimes be difficult to handle as it is. For example, in the case of melt molding, if PVB is smoothly supplied to the molding machine, it will be difficult to handle the powder as it is. Therefore, in this case, it is preferable to manufacture PVB particles.

The moisture content of the PVB powder used in the production of the PVB particles is preferably 5% by mass or less. By adjusting the moisture content to less than 5% by mass, the butyraldehyde content of the PVB particles obtained can be reduced because the butyraldehyde is not prevented from being volatilized due to the excess volatilization. On the other hand, if the moisture content is too small, the powder is likely to scatter and cause dust explosion, so the moisture content is preferably 0.1% by mass or more. The method of adjusting the water content of the PVB powder to the above range includes a method of adjusting the drying conditions after the neutralization treatment and the water washing.

The PVB powder obtained in this way is put into an extruder and melt-kneaded to produce pellets. At this time, the particles were melt-kneaded under reduced pressure to remove the volatile portion using at least one exhaust port. Preferably, the butyraldehyde content of the PVB particles can be reduced. As for the extruder, a single-shaft extruder or a double-shaft extruder can be used, and an extruder with a plurality of exhaust ports is more suitable. The temperature of the resin during melt-kneading is preferably 220 ° C or higher and higher than the melting temperature of PVB. By melt-kneading at a lower temperature of 220 ° C or lower, the acid value of the obtained PVB particles can be reduced, and the butyraldehyde content can also be reduced.

The pressure to be reduced by the exhaust port is 0.008 MPa or less. The following is better. Here, the pressure of "0.008 MPa or less" is expressed as an absolute pressure, and if it is expressed in a reduced pressure, it is "0.092 MPa or more". In this way, by performing melt-kneading at such a low pressure (high degree of reduced pressure) at a lower temperature, the acid value of the obtained PVB particles can be reduced, and the butyraldehyde content can also be reduced.

As described above, after melt-kneading with an extruder, PVB particles can be obtained after cutting out. As for the extrusion method, a method of extruding molten resin in a wire harness shape is preferable. The cutting method is preferably a method of cutting with a cutter such as a rotary cutter.

PVB particles used in the present invention obtained in this way The acid value is preferably 0.2 mgKOH / g or less. When the acid value is more than 0.2 mgKOH / g, the PVB is decomposed during melt spinning, and the butyraldehyde content of the obtained PVB fiber is increased, resulting in malodor. More preferably, it is 0.1 mgKOH / g or less.

Moreover, the butyraldehyde content of the PVB particles is 10 mass ppm or less Is better. When the butyraldehyde content is greater than 10 mass ppm, the PVB is decomposed during melt spinning, and the butyraldehyde content of the obtained PVB fibers is increased, resulting in malodor. More preferably, it is 5 mass ppm or less.

Also, the melt flow rate of the PVB particles used in the present invention The melt flow rate (MFR) is preferably 0.5 to 45 g / 10 minutes. When the MFR is less than 0.5 g / 10 minutes, the fluidity decreases, and fibrosis becomes difficult. On the other hand, when the MFR is more than 45 g / 10 minutes, the fluidity is high, the strength as a fiber is reduced, and use becomes difficult. The MFR is more preferably 1 to 40 g / 10 minutes. The MFR in the present invention is measured in accordance with the JIS K7210 test method, and indicates the amount of 10 minutes when the polymer melted at 150 ° C is extruded from the capillary under a load of 2.16 kgf.

Using the PVB particles obtained in this way, Invented PVB fiber. Specifically, a polyvinyl butyral having a butyralization degree of 50 to 90% by mass, an MFR of 2.16 kgf at 150 ° C. of 0.5 to 45 g / 10 minutes, and an acid value of 0.2 mg KOH / g or less is used. It is preferred that the particles made of aldehyde be melt-spun at a temperature below 240 ° C. When the spinning temperature is 240 ° C or higher, the thermal decomposition of PVB is intense, and the production of butyraldehyde, which is a cause of malodor, is promoted. The spinning temperature is more preferably 230 ° C or lower, and still more preferably 220 ° C or lower.

The PVB fiber of the present invention manufactured as described above, The aldehyde content is 20 ppm by mass or less. In order to obtain such PVB fibers with low butyraldehyde content, it is extremely important to use PVB particles with low acid value and very low butyraldehyde content, as described above, and perform melt spinning at low temperature to suppress the production of butyraldehyde in the spinning step. . Thereby, the PVB fiber whose odor generation is highly suppressed can be obtained initially.

The PVB fiber of the present invention may be made of only polyvinyl butyral Single fiber, composite fiber with polyvinyl butyral as one component, or mixed fiber with polyvinyl butyral as one component Either of the two dimensions. In addition, PVB fibers may be mixed into the inorganic fiber layer. It is only necessary to use PVB as one of the components. Among them, the composite fiber may be exemplified by a core-shell type composite fiber using other polymers in a core component and PVB in a shell component; or a split type composite fiber having a structure in which other polymers are bonded to PVB. The PVB fibers of the present invention may be long fibers or short fibers.

In the spinning step when manufacturing the PVB fiber of the present invention, The molten PVB resin is spun from a nozzle using a common melt spinning device. The sectional shape and diameter of the obtained fiber can be arbitrarily set according to the shape and size of the nozzle.

When melt spinning to obtain long fibers, PVB pellets are melt-kneaded with a single-shaft extruder or a double-shaft extruder. The spinning after melt-kneading is preferably performed at a spinning temperature of 170 ° C or higher and less than 240 ° C. If the spinning temperature is lower than 170 ° C, the viscosity of the polymer becomes too high, and fibrillation becomes difficult. If it is 240 ° C or higher, the thermal decomposition of PVB is intense, and the production of butyraldehyde, which is a cause of malodor and reelability, is promoted. In addition, the PVB particles to be used are preferably dried to a moisture content of 2000 mass ppm or less. When the moisture content is more than 2000 mass ppm, fibrillation becomes difficult. It is more preferably 1,000 mass ppm or less, and still more preferably 500 mass ppm or less.

Next, the melt-spun PVB fibers are temporarily cooled to The temperature below the glass transition temperature is preferably a temperature that is 10 ° C or more lower than the glass transition temperature. As for the cooling method and the cooling device in this case, any method and device can be used as long as it can cool the spun PVB fiber below its glass transition temperature, but it is not particularly limited, but A cooling air blowing device such as a cooling air blowing cylinder is provided below the spinning nozzle, and the cooling wind is blown to the spun PVB fiber, and it is preferably cooled below the glass transition temperature. At this time, the cooling conditions such as the temperature or humidity of the cooling air, the blowing speed of the cooling air, and the blowing angle of the cooling wind to the spun yarn are not particularly limited, as long as it is a PVB fiber that can be spun from the nozzle, no fiber will In the case of swaying, etc., any conditions can be rapidly and uniformly cooled below the glass transition temperature. Among them, under the conditions that the temperature of the cooling wind is 20 ° C to 30 ° C, the humidity of the cooling wind is 20% to 60%, and the blowing speed of the cooling wind is 0.4 to 1.0m / second, the cooling wind is blown to the spun fiber. The direction is adjusted to be perpendicular to the spinning direction, and cooling of the spun PVB fibers is performed. Since the high-quality PVB fibers can be smoothly obtained, it is preferable. In the case where a cooling air blower is used to perform cooling under the aforementioned conditions, it is preferable to arrange a cooling air blower having a length of about 80 to 120 cm with a small interval directly below the spinning nozzle or without a gap.

After spinning, the yarn is temporarily cooled to a glass transition temperature to After that, it can be continuously passed through the direct heating zone as it is. Specifically, it is extended to heat treatment in a device such as a tube-shaped heating cylinder, and after being applied with an oil agent, it is wound up at a speed of 2000 to 5000 m / min. Good, stable quality stretch yarn.

The oil agent is subjected to an extension treatment step by a heating device Given later. This reduces the number of broken wires caused by the oil. The method of applying the oil agent may be any one of an additional method using a gear pump type refueling nozzle and an additional method using a refueling roller. However, if the spinning speed is to be increased, the former method is more suitable for the non-mottled yarn and stable oil. Regarding the amount of oil agent attached, there is no particular limitation, as long as the What is necessary is just to obtain the range which is suitable for the manufacturing process of a fiber assembly, and the effect of suppressing a broken thread and the fluff of a raw silk can be adjusted suitably. Among them, it is better to adjust the adhesion amount of the oil agent to 0.3 to 2.0% by mass, because it can smoothly obtain high-quality PVB fibers, and it is more preferable to adjust it to 0.3 to 1.0% by mass.

Next, it is preferable to pull at a speed of 2000 ~ 5000 meters / minute Take the PVB fiber extended through the above-mentioned series of steps, and the drawing speed is more preferably 2500 ~ 4000 meters / minute. When the pulling speed of the PVB fiber is less than 2500 meters / minute, the productivity is reduced, and the fiber stretching in the heating area cannot be sufficiently performed, and the mechanical properties of the obtained PVB fiber are reduced. When the pulling speed exceeds 5000 meters / minute, it is difficult to obtain stable high-speed spinning properties, and the fiber stretching in the heating area cannot be sufficiently performed, and the mechanical properties of the obtained PVB fibers are reduced.

A preferred embodiment of the present invention includes the PVB fiber Dimensional fiber assembly. Examples of the fiber assembly include nonwoven fabrics, woven fabrics, paper, and knitted fabrics. When used as an adhesive layer, it is suitable for a woven or non-woven fabric.

The fiber assembly containing the PVB fiber of the present invention is particularly preferably a fabric having a basis weight (basic weight) of 1 to 100 g / m ² . When the mass per unit area is less than 1 g / m ² , even if the fiber assembly is thermally fused, the target material such as a glass fiber layer is adhered to, and since the number of attachment points is small, the adhesion strength becomes insufficient. On the other hand, when it exceeds 100 g / m ² , it is difficult to transfer heat during heating and bonding, and the bonding strength becomes weak. The basis weight is more preferably 5 to 50 g / m ² . In addition, although the fiber diameter may be appropriately controlled depending on the application, in consideration of processability, fiber strength, and bonding performance, 0.5 to 40 μm is preferable, and 3 to 20 μm is more preferable. The cross-sectional shape of the fiber is not particularly limited.

In the present invention, the PVB resin is A nonwoven fabric composed of continuous fibers spun at a spinning temperature of 240 ° C is preferred. In the case where the spinning temperature is 240 ° C or higher, the thermal decomposition of PVB is intense, and the production of butyraldehyde, which is a cause of malodor, is not good.

The type of the nonwoven fabric used in the present invention is not particularly limited. Non-woven fabrics entangled with short fibers may be used, and continuous-fiber non-woven fabrics may be used. When the short fibers are entangled, methods such as needle punch or water jet can be used.

However, it can be ignored in carding steps and the like. Considering the strength of the single fiber required to form the fabric, it is preferable to use a continuous fiber nonwoven fabric in the present invention. The form of the continuous fiber nonwoven fabric is not particularly limited, and examples thereof include a spun-bond nonwoven fabric and a melt-blown nonwoven fabric. However, the melt-blown nonwoven fabric is particularly preferable in that it can be fine-density and can be directly manufactured into a nonwoven fabric after melt extrusion.

Hereinafter, the case where a meltblown nonwoven fabric is manufactured is demonstrated concretely. As an example of the case of manufacturing by the melt-blowing method, a previously known melt-blowing device can be used as the spinning device. As for the spinning conditions, the diameter of the spinning nozzle is 0.2 to 0.5 mm, and the single-hole discharge amount is 0.1 ~ 1.0g / min, air volume per nozzle meter is 5 ~ 20Nm ³ / min, spinning temperature is above 170 ° C and below 240 ° C, hot air temperature (primary air temperature) is above 180 ° C The temperature is preferably lower than 250 ° C. If the spinning temperature is lower than 170 ° C, the viscosity of the polymer becomes too high during fiberization, and it becomes difficult to refine it with heated air. On the other hand, if it is 240 ° C or higher, the thermal decomposition of the polymer is intense, and the production of butyraldehyde, which is a cause of malodor, is promoted. The PVB particles used are preferably dried to a moisture content of 5000 mass ppm or less. If the moisture content is more than 5000 mass ppm, it becomes difficult to become a continuous fiber nonwoven fabric. It is more preferably 1,000 mass ppm or less, and still more preferably 500 mass ppm or less.

Hereinafter, the case of manufacturing a spunbond nonwoven fabric is demonstrated concretely. In the case of manufacturing by the spunbond method, a previously known spunbond device can be used as the spinning device. In terms of spinning conditions, the hole diameter of the spinning nozzle is 0.2 to 1mm, and the single-hole output is 0.1 to 2.0 g / min, elongation air of 500-5000 m / min, and spinning conditions of 150 ° C or more and less than 240 ° C are preferred. If the spinning temperature is lower than 150 ° C, the polymer viscosity becomes too high during fiberization, the nozzle pressure becomes high, and it becomes difficult to spit out. On the other hand, if it is 240 ° C or higher, the thermal decomposition of the polymer is intense, and the production of butyraldehyde, which is a cause of malodor, is promoted. The PVB particles used are preferably dried to a moisture content of 5000 mass ppm or less. When the moisture content is more than 5000 mass ppm, it becomes difficult to form a continuous fiber nonwoven fabric. It is more preferably 1,000 mass ppm or less, and still more preferably 500 mass ppm or less.

As for the continuous fiber nonwoven fabric of the present invention, the mass per unit area of the meltblown nonwoven fabric used is preferably 1 to 100 g / m ² . When the mass per unit area is less than 1 g / m ² , even if the nonwoven fabric is thermally fused and adhered to a target material such as a glass fiber layer, the number of bonding points decreases, and the bonding strength becomes insufficient. On the other hand, when it exceeds 100 g / m ² , heat transfer becomes difficult during heating and bonding, and the bonding strength becomes weak. 5 ~ 50g / m ² is more preferable. Although the fiber diameter may be appropriately controlled depending on the application, it is more preferably 0.5 to 40 μm, and more preferably 3 to 20 μm in consideration of processability, strength of the non-woven fabric, and adhesion performance.

As for the continuous fiber nonwoven fabric of the present invention, the unit area mass of the spunbond nonwoven fabric used is preferably 5 to 200 g / m ² . If the mass per unit area is less than 5 g / m ² , the texture is too coarse, and then the strength decreases. On the other hand, when it exceeds 200 g / m ² , heat transfer becomes difficult during heating and bonding, and the bonding strength becomes weak. 10 to 150 g / m ² is more preferable, and 20 to 100 g / m ² is more preferable. Although the fiber diameter in the spunbond non-woven fabric can be appropriately controlled depending on the application, if the strength and adhesion properties of the non-woven fabric are considered, 5 to 50 μm is preferred, and 10 to 40 μm is more preferred. The cross-sectional shape of the fiber is not particularly limited.

In the present invention, a laminated body, particularly a laminated body for interior materials, can be obtained by using a fiber assembly containing PVB fibers as an adhesive layer. A particularly preferred embodiment is a laminated body in which a plurality of layers are bonded through a bonding layer composed of PVB fiber aggregates. The aforementioned knitted fabric is interposed between a plurality of layers and the PVB fibers are melted by heating, so that the plurality of layers can be adhered to each other. In this case, it is preferable to apply pressure while heating.

The plurality of layers laminated through the above-mentioned adhesive layer are not particularly limited, and it is preferable that the inorganic fiber layer and other layers are adhered via the adhesive layer. This is because PVB shows good adhesion to inorganic fibers. The inorganic fiber layer used therein is not particularly limited, and a carbon fiber layer or a metal fiber layer can be used. However, in terms of versatility, a glass fiber layer is preferred.

A further preferred embodiment of the laminated body of the present invention is the aforementioned inorganic fiber layer, foam layer, and surface material layer via the aforementioned bonding layer The resulting laminated body. A particularly preferred application of the laminated body of the present invention is an interior material.

In the following, the glass fiber layer and the foam layer are explained with examples. An interior material composed of a laminated body in which a surface material layer is laminated with the aforementioned adhesive layer. FIG. 1 is a cross-sectional view showing an example of a vehicle interior material for a typical application of the present invention.

The interior material 10 is placed on both sides of the foam layer 1, and the glass fiber The dimension layers 2, 3 and the surface material layers 4, 5 are laminated, and these are then integrated to form a desired product shape such as a ceiling material. The adhesion and shape of the foregoing layers are fixed to each other by the adhesive layer 6 existing between the foam layer 1 and the adjacent glass fiber layers 2 and 3 and between the glass fiber layers 2 and 3 and the surface material layers 4 and 5. Melting is performed next, wherein the adhesive layer 6 is composed of a fiber assembly containing the PVB fibers of the present invention. The method of forming the interior material 10 is described later, and the fiber assembly can be laminated between the surface material layers 4 and 5 and the glass fiber layers 2 and 3 and between the glass fiber layers 2 and 3 and the foam layer 1 by arranging. , And then hot pressing it to get.

The density of the fiber assembly containing the PVB fiber of the present invention, which is laminated and laminated between the glass fiber layers 2, 3 and the foam layer 1, or between the glass fiber layers 2, 3 and the surface material layers 4, 5 is arranged from the bulkiness From the viewpoint of bulky, 0.005 to 0.4 g / cm ³ is preferable. If the density of the fiber assembly is too small, the morphological stability is deteriorated, which is not preferable. Conversely, if the density is greater than 0.4 g / cm ³ , the bulkiness is poor, and the sound absorption for the purpose of the present invention is reduced. The density of the fiber assembly is more preferably 0.01 to 0.3 g / cm ³ .

In the above-mentioned interior material 10, the foam layer 1 constitutes the interior material For the core material of material 10, semi-rigid or rigid polyurethane Various materials such as ester foam. The thickness of the foam layer 1 can be appropriately determined depending on the type of the vehicle interior material 10 and the like of the target.

Glass fiber layers 2 and 3 are used to improve the rigidity of the interior material 10. For the purpose of performance, the laminate is adhered to both sides of the foam layer 1. The glass fiber layers 2 and 3 can be appropriately selected, and those having a mat shape in advance, or those in which glass fibers having a predetermined fiber length are stacked to form a layer shape during the manufacture of the interior material 10 can be used. The thickness of the glass fiber layers 2 and 3, the fiber length of the glass fiber, or the mass per unit area of the glass fiber layer may be appropriately determined depending on the use or shape of the interior material 10.

The surface material layers 4 and 5 are for the internal protection of the interior material 10 For protection or decoration, etc., provided on the outer surface of the glass fiber layers 2 and 3, one surface material layer 5 constitutes the back surface of the interior material 10, and the other surface material layer 4 constitutes the front surface. As for the surface material layers 4 and 5, it is suitable to use a non-woven fabric, synthetic leather, a plastic film, or the like alone, or a foam and a plastic film to be laminated. Of course, the surface material layer 4 and the surface material layer 5 are not necessarily the same material.

As described above, by combining the glass fiber layers 2, 3 and the foam layer 1 Between the glass fiber layers 2, 3 and the surface material layers 4, 5 with an adhesive layer 6 composed of a fiber assembly containing the PVB fibers of the present invention, the peeling of the interface is not easy to occur, and sound absorption is formed Good sex. On the other hand, if it is adhered by, for example, an adhesive film, there is a case where the air permeability is poor and the sound absorption performance is lowered, which is not preferable.

If a fiber aggregate containing the PVB fiber of the present invention is used, , The following steps can be simplified when forming a laminated body such as a vehicle interior material. Furthermore, the generation of malodor in the subsequent steps can be suppressed. Again, in the In the subsequent steps, energy saving (low temperature / low pressure) can be used. Therefore, it is suitable to use as an adhesive for a skin layer or a buffer layer of a molded interior material for automobiles, railway vehicles, and ships that is lightweight, excellent in sound absorption and shock resistance. The laminated body obtained in this way can ensure the thickness of the structural body when used as an interior material or a ceiling material, and has excellent rigidity, sound absorption, and thermal deformation resistance.

[Example]

Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples. In addition, each physical property value in an Example means the one measured according to the following measuring method.

[Basic weight of fabric and non-woven fabric (g / m ² )]

Measured in accordance with JIS P8124.

[Thickness (mm), density (g / m ³ ) of fabric and non-woven fabric]

After the obtained fabric and non-woven fabric were left in a standard environment (temperature 20 ° C, relative humidity 65%) for more than 4 hours, the PEACOCK H-type hand-thickness gauge (Dial-Thickness Gauge H Type) (Ata Precision Co., Ltd. system; 10 mm × 180 g / cm ² ) The thickness was measured at five locations, and the thickness of the nonwoven fabric was represented by an average value. The density is calculated by dividing the basis weight by the thickness.

[Acid value of PVB (mgKOH / g)]

Measured in accordance with JIS K6728: 1977.

[Butyral content of PVB (mass ppm)]

Headspace gas chromatography GC-14B manufactured by Shimadzu Corporation was used as a measurement device, and TC-1 (inner diameter 0.25 mm, length 30 m) manufactured by GL Science Inc. was used as a column for measurement.

[Smell judgment]

When the obtained fabric and non-woven fabric were treated, these odors were confirmed by a functional test, and evaluated according to the following criteria.

A: There is almost no odor.

B: A little odor was felt.

C: A bad smell is felt.

[Unwinding]

Using a winder, the unwound PVB fiber is wound at a speed of 200 meters / minute from a silk roll made of long PVB fibers. Unwindability evaluation was performed based on the following criteria.

○; When unwinding was performed at a unwinding speed of 200 m / min for 300 minutes, no filament breakage occurred, and no lint / loop occurred in the obtained fiber. Unwinding is good.

×; When unwinding was performed at a unwinding speed of 200 m / min for 300 minutes, filament breakage occurred more than once, and more than one fluff or loop occurred in the obtained fiber. Poor unwinding.

[Spinability judgment]

The continuous spinning time when the melt-blown nonwoven fabric and the spunbond nonwoven fabric were manufactured was evaluated. Specifically, the time from the start of spinning to the time when the resin (polymer mass) that is thermally degraded in the spinning nozzle is generated and the nozzle is stained or broken is measured.

[Thickness (mm) of interior material (layer), density (g / m ³ ) of interior material (layer)

After placing the molded interior material (layered body) in a standard environment (temperature 20 ° C, relative humidity 65%) for more than 4 hours, PEACOCK MODEL PDN12 (manufactured by Yasuda Seiki Seisakusho Co., Ltd .; 16mm × 550g / cm ² ) The thickness was measured at five locations, and the thickness of the interior material (layered body) was represented by an average value. The density is calculated by dividing the basis weight of the interior material (layered body) by the thickness.

[Peel strength (adhesive strength) (N / 15mm)]

For the molded interior material 10 shown in FIG. 1, the laminate is cut to a width of 15 mm, and the foam layer 1 (urethane foam) in the interior material 10 (the laminate) and glass are cut. The peel strength of the fiber layer 2 was measured by an Instron 5543, the end portion of the sample rupture portion was clamped by two chucks, and measured at a test speed of 100 mm / min.

[Bending elastic gradient (N / 50mm / cm), maximum bending load (N / 50mm)]

Place the formed internal material (layered body) sample (width 50mm × length 150mm) on the sample receiver (front end R5 × width 50mm; pitch 100mm), and place the center of the internal material (layered body) sample (sample reception) The distance from the center to the center), with the sample shaper (front end R5 × width 50mm) of the same shape as the sample receiver, extruded from above at a speed of 50mm / min, from the graph at the time of extrusion, along the initial gradient Draw a straight line and read the load (N) as the bending elastic gradient. The maximum load (N) was read from the obtained graph as the maximum bending load.

[Sound absorption rate (%)]

In accordance with JIS A1405, the sound absorption of the normal incidence method was measured. The average value of the sound absorption rates at 1000 Hz and 2000 Hz was used as a representative value.

[Example 1]

(Manufacture of PVB powder)

1295 g of ion-exchanged water and 105 g of polyvinyl alcohol (polymerization degree 300, saponification degree 98 mol%) were added to a glass container having a volume of 2 liters with a reflux cooler, a thermometer, and an anchor-type stirring wing. The temperature was raised to 95 ° C. to completely dissolve the PVA to form an aqueous PVA solution (concentration: 7.5% by mass). The formed PVA aqueous solution was continuously stirred at a rotation speed of 120 rpm, and was slowly cooled to 10 ° C. over about 30 minutes. Then, 58 g of butyraldehyde and an acid catalyst (butyralization catalyst) were added to the aqueous solution. 90 ml of hydrochloric acid having a concentration of 20% by mass started the butyralization of PVA. After 150 minutes of butyralization, the whole was heated to 50 ° C. over 60 minutes, and maintained at 50 ° C. for 120 minutes, and then cooled to room temperature. The resin precipitated by cooling was filtered, washed with ion-exchanged water (100 times the amount of ion-exchanged water with respect to the resin), and then a 0.3% by mass sodium hydroxide solution for neutralization was added and maintained at 40 ° C for 10 After hours, it was washed again with 100 times the amount of ion-exchanged water. After dehydration, it was dried at 40 ° C. under reduced pressure for 18 hours to obtain a polyvinyl butyral powder (water content: 1.0% by mass).

(Manufacture of PVB particles)

A twin-axis extruder (manufactured by Toshiba Machine Co., Ltd.) in the same direction with L / D = 54 was used as the melt extruder. There were two exhaust sections, and the pressure in the exhaust section was reduced from the hopper side to 0.005 And 0.003 MPa; the polyvinyl butyral powder obtained above was introduced into the extruder. The strand-shaped molten resin coming out of the die hole was cooled in a water tank, and then pelletized with a granulator to obtain a granular polyvinyl butyral resin having a diameter of 1.6 mm and a length of 1.6 mm (a water content of 0.2% by mass). . Extrusion conditions of molten resin: the number of screw rotations is 300 times / minute, the resin speed is 120 kg / hour, and the resin temperature is 200 ° C.

(Analysis of PVB particles)

The obtained PVB particles had a degree of butyralization of 68 mol%, a content of residual acetamyl (vinyl acetate unit) was 2 mol%, and a content of residual hydroxyl (vinyl alcohol unit) was 30 mol. %. The content of butyraldehyde was 3.5 mass ppm, and the acid value was 0.09 mgKOH / g.

(Manufacture of PVB long fiber)

Using the above-mentioned PVB pellets, melt spinning was performed at a spinning temperature of 205 ° C. and a single-hole discharge rate of 1.57 g / min using a nozzle with 24 holes. After spinning, the filament was blown with cooling air at a temperature of 20 ° C and a humidity of 60% at a speed of 0.5 m / sec. After cooling the filament to below 50 ° C, the filament was introduced 1.2 m below the spinning nozzle. In the tube heater (inner temperature 130 ℃), the length of the tube heater is 1.0m, the diameter of the inlet guide rod is 8mm, the diameter of the outlet guide rod is 10mm, and the internal diameter is 30mm ; After extending inside the tube heater, apply oil to the filament coming out of the tube heater through the oiling nozzle, and take it up at a speed of 3500 meters / minute through 2 take-up rollers to obtain a PVB of 84T / 24f Long fibers. The unwound property of the wound fiber was evaluated, and the results are shown in Table 1.

(Manufacturing of laminated body)

Using the PVB fibers obtained above, a plain fabric having a basis weight of 44.1 g / m ² and a thickness of 0.237 mm was obtained. In the same manner as in Fig. 1, the obtained fabric was used as the adhesive layer 6 and laminated in a layered manner. At this time, as the foam layer 1, a polyether-based rigid urethane foam (manufactured by INOAC Co., Ltd.) having a basis weight of 180 g / m ² and a thickness of 6 mm was used; ), Using a basis weight of 100 g / m ² and a thickness of 20 mm. In addition, as the surface material layer 5 constituting the back surface of the interior material 10, a polyester fiber nonwoven fabric (manufactured by Maeda Kogyo Co., Ltd.) having a basis weight of 25 g / m ² is used; A polyester fiber nonwoven fabric (manufactured by Maeda Kogyo Co., Ltd.) having a basis weight of 220 g / m ² was used. These laminates were press-formed under a pressing condition of a pressing temperature of 130 ° C., a pressing time of 30 seconds, and a pressure of 0.3 kg / cm ^{2 to} obtain an interior material 10. Table 1 shows the butyraldehyde content and odor judgment results of the obtained fabric, and the performance measurement results of the interior material 10.

[Example 2]

Using the same PVB pellets as in Example 1, according to the same spinning temperature and the same spinning conditions, PVB long fibers were obtained. The unwinding property of the obtained fiber is shown in Table 1. A woven fabric having a basis weight of 23.3 g / m ² and a thickness of 0.177 mm was obtained by using the obtained fibers. Using the obtained woven fabric as the bonding layer 6 shown in FIG. 1, press molding was performed according to the same layer structure and conditions as in Example 1 to obtain an interior material 10. Table 1 shows the butyraldehyde content and odor judgment results of the obtained fabric, and the performance measurement results of the interior material 10.

[Example 3]

Using the same PVB pellets as in Example 1, except that the spinning temperature was changed to 200 ° C, PVB long fibers were obtained in the same manner as in Example 1. The unwinding property of the obtained fiber is shown in Table 1. Further, using the obtained fiber, a woven fabric having a basis weight of 30.2 g / m ² and a thickness of 0.441 mm was obtained. The obtained fabric was used as the adhesive layer 6 shown in FIG. 1 and laminated with the same layer structure as in Example 1. The pressing conditions were a pressing temperature of 140 ° C., a pressing time of 25 seconds, and a pressure of 0.2 kg / cm ² . Press molding is performed to obtain the interior material 10. Table 1 shows the butyraldehyde content and odor judgment results of the obtained fabric, and the performance measurement results of the interior material 10.

[Example 4]

Using the same PVB pellets as in Example 1, except that the spinning temperature was changed to 230 ° C, PVB long fibers were obtained in the same manner as in Example 1. The unwinding property of the obtained fiber is shown in Table 1. Moreover, using the obtained fiber, a woven fabric having a basis weight of 24.0 g / m ² and a thickness of 0.242 mm was obtained. The obtained woven fabric was used as the bonding layer 6 shown in FIG. 1, and was press-molded under the same layer structure and conditions as in Example 1 to obtain an interior material 10. Table 1 shows the butyraldehyde content and odor judgment results of the obtained fabric, and the performance measurement results of the interior material 10.

[Example 5]

Using the same PVB particles as in Example 1, a composite fiber with a shell of PVB and a core of PP was formed. PVB long fibers were obtained in the same manner as in Example 1 except that the spinning temperature was changed to 210 ° C. The unwinding property of the obtained fiber is shown in Table 1. Further, using the obtained fibers, a woven fabric having a basis weight of 30.2 g / m ² and a thickness of 0.445 mm was obtained. The obtained fabric was used as an adhesive layer 6 as shown in FIG. 1, and was press-molded under the same layer structure and the same pressing conditions as in Example 3 to obtain an interior material 10. Table 1 shows the butyraldehyde content and odor judgment results of the obtained fabric, and the performance measurement results of the interior material 10.

[Comparative Example 1]

Except that in Example 1, the pressure in the exhaust portion of the melt extruder was reduced from the hopper side to 0.02 and 0.01 MPa (gauge pressures were 0.08 and 0.09 MPa, respectively), and PVB was manufactured in the same manner as in Example 1. Particles. The obtained PVB particles had a degree of butyralization of 68 mol%, a content of residual acetamyl (vinyl acetate unit) was 2 mol%, and a content of residual hydroxyl (vinyl alcohol unit) was 30 mol %. The content of butyraldehyde was 15 mass ppm, and the acid value was 0.31 mgKOH / g. Except that the PVB particles obtained in this way were used, PVB long fibers were obtained in the same manner as in Example 1. The unwinding property of the obtained fiber is shown in Table 1. Further, using the obtained fiber, a woven fabric having a basis weight of 23.0 g / m ² and a thickness of 0.233 mm was obtained. The obtained woven fabric was used as the bonding layer 6 shown in FIG. 1, and was press-molded under the same layer structure and conditions as in Example 1 to obtain an interior material 10. Table 1 shows the butyraldehyde content and odor judgment results of the obtained fabric, and the performance measurement results of the interior material 10.

[Comparative Example 2]

Using the same PVB pellets as in Example 1, except that the spinning temperature was changed to 240 ° C, PVB long fibers were obtained in the same manner as in Example 1. The unwinding property of the obtained fiber is shown in Table 1. A woven fabric having a basis weight of 24.5 g / m ² and a thickness of 0.250 mm was obtained by using the obtained fibers. The obtained woven fabric was used as the bonding layer 6 shown in FIG. 1, and was press-molded under the same layer structure and conditions as in Example 1 to obtain an interior material 10. Table 1 shows the butyraldehyde content and odor judgment results of the obtained fabric, and the performance measurement results of the interior material 10.

[Comparative Example 3]

PVB long fibers were obtained in the same manner as in Example 1 except that the same PVB as in Comparative Example 1 was used, except that the spinning temperature was changed to 240 ° C. The unwinding property of the obtained fiber is shown in Table 1. Further, using the obtained fiber, a woven fabric having a basis weight of 31.2 g / m ² and a thickness of 0.451 mm was obtained. The obtained fabric was used as an adhesive layer 6 as shown in FIG. 1, and was press-molded under the same layer structure and the same pressing conditions as in Example 3 to obtain an interior material 10. Table 1 shows the butyraldehyde content and odor judgment results of the obtained fabric, and the performance measurement results of the interior material 10.

[Comparative Example 4]

PP long fibers were obtained in the same manner as in Example 1 except that polypropylene (manufactured by Prime Polymer Co., Ltd.) was used and the spinning temperature was changed to 280 ° C. The unwinding property of the obtained fiber is shown in Table 1. Further, using the obtained fibers, a woven fabric having a basis weight of 24.0 g / m ² and a thickness of 0.202 mm was obtained. The obtained woven fabric was used as the adhesive layer 6 and press-molded under the same layer structure and conditions as in Example 1 to obtain an interior material 10. Table 1 shows the results of determining the odor of the obtained fabric and the results of measuring the performance of the interior material 10.

[Comparative Example 5]

A PE long fiber was obtained in the same manner as in Example 1 except that polyethylene (manufactured by Japan Polyethylene Corporation) was used and the spinning temperature was changed to 260 ° C. The unwinding property of the obtained fiber is shown in Table 1. Moreover, using the obtained fiber, a woven fabric having a basis weight of 30.1 g / m ² and a thickness of 0.231 mm was obtained. The obtained woven fabric was used as the adhesive layer 6 and press-molded under the same layer configuration as in Example 1 and the same pressing conditions as in Example 3 to obtain an interior material 10. Table 1 shows the results of determining the odor of the obtained fabric and the results of measuring the performance of the interior material 10.

As shown in Table 1, the acid value is 0.2 mgKOH / g or less. The fabrics of Examples 1 to 5 composed of fibers made of PVB particles at a spinning temperature lower than 240 ° C have a low butyraldehyde content, a significant improvement in odor, and good unwinding properties of the fibers. By using the fabric as an adhesive layer, the obtained interior material has a peeling strength (adhesive strength) of 0.5N / 15mm or more even under the low-temperature / low-pressure pressing conditions, and also ensures a sound absorption of 65% or more. The elastic gradient and the maximum bending load also show excellent values.

On the other hand, as shown in Table 1, using an acid value exceeding 0.2mgKOH / g of PVB pellets, or Comparative Examples 1 to 3 spun at a temperature of 240 ° C or higher, the obtained fabric had a high butyraldehyde content, odor was felt, and the unwinding property was poor. In Comparative Examples 4 and 5 using polypropylene fabric or polyethylene fabric, the peel strength (adhesion strength) was 0.5 N / 15 mm or less, and the laminated body had insufficient rigidity and became easy to peel, and the sound absorption rate was 65. % Or less, the comfort is also poor in terms of sound absorption.

[Example 6]

The PVB pellets obtained in Example 1 were used to produce a meltblown nonwoven fabric. A spinning nozzle provided with 1,000 nozzle holes having a diameter of 0.4 mm per 1 m width was used to extrude the resin at a spinning temperature of 205 ° C and a discharge amount of 0.5 g / min / hole. Each nozzle with a width of 1 meter blows 12Nm ³ / minute of hot air to extend it. In this way, a melt-blown nonwoven fabric having a fiber diameter of 5 μm, a basis weight of 46.4 g / m ² , and a thickness of 0.296 mm was obtained. The time from the start of spinning to the generation of agglomerates is 16 hours or more. The obtained melt-blown nonwoven fabric was used as the bonding layer 6 in FIG. 1 and was press-molded in the same manner as in Example 1 to obtain an interior material 10. Table 2 shows the butyraldehyde content and odor judgment results of the obtained meltblown nonwoven fabric, and the performance measurement results of the interior material 10.

[Example 7]

Using the same PVB pellets as in Example 6, and using the same spinning temperature, a melt-blown nonwoven fabric having a basis weight of 24.5 g / m ² and a thickness of 0.221 mm was obtained. The time from the start of spinning to the generation of agglomerates is 16 hours or more. Using the obtained melt-blown nonwoven fabric as the bonding layer 6 shown in FIG. 1, press molding was performed in the same manner as in Example 6 to obtain an interior material 10. Table 2 shows the butyraldehyde content and odor judgment results of the obtained meltblown nonwoven fabric, and the performance measurement results of the interior material 10.

[Example 8]

The same PVB pellets as in Example 6 were used, and the spinning temperature was changed to 230 ° C to obtain a melt-blown nonwoven fabric having a basis weight of 25.3 g / m ² and a thickness of 0.242 mm. The time from the start of spinning to the generation of lumps was 11 hours. Using the obtained melt-blown nonwoven fabric as the bonding layer 6 shown in FIG. 1, press molding was performed in the same manner as in Example 6 to obtain an interior material 10. Table 2 shows the butyraldehyde content and odor judgment results of the obtained meltblown nonwoven fabric, and the performance measurement results of the interior material 10.

[Example 9]

Except that the pressure in the exhaust portion of the melt extruder in Example 1 was reduced from the hopper side to 0.006 and 0.004 MPa, PVB pellets were produced in the same manner as in Example 1. The obtained PVB particles had a degree of butyralization of 68 mol%, a content of residual acetamyl (vinyl acetate unit) was 2 mol%, and a content of residual hydroxyl (vinyl alcohol unit) was 30 mol. %. The content of butyraldehyde was 10 ppm by mass, and the acid value was 0.16 mgKOH / g. A melt-blown nonwoven fabric having a basis weight of 25.3 g / m ² and a thickness of 0.242 mm was obtained in the same manner as in Example 6 except that the PVB particles obtained in this manner were used. The time from the start of spinning to the generation of lumps was 12 hours. Using the obtained melt-blown nonwoven fabric as the bonding layer 6 shown in FIG. 1, press molding was performed in the same manner as in Example 6 to obtain an interior material 10. Table 2 shows the butyraldehyde content and odor judgment results of the obtained meltblown nonwoven fabric, and the performance measurement results of the interior material 10.

[Comparative Example 6]

A melt-blown nonwoven fabric having a basis weight of 24.2 g / m ² and a thickness of 0.233 mm was obtained in the same manner as in Example 6 except that the same PVB particles as in Comparative Example 1 were used. The time from the start of spinning to the generation of lumps was 6 hours. Using the obtained melt-blown nonwoven fabric as the bonding layer 6 shown in FIG. 1, press molding was performed in the same manner as in Example 6 to obtain an interior material 10. Table 2 shows the butyraldehyde content and odor judgment results of the obtained meltblown nonwoven fabric, and the performance measurement results of the interior material 10.

[Comparative Example 7]

A melt-blown nonwoven fabric having a basis weight of 25.8 g / m ² and a thickness of 0.25 mm was obtained in the same manner as in Example 1 except that the same PVB pellets as in Example 6 were used and the spinning temperature was changed to 240 ° C. The time from the start of spinning to the generation of lumps was 5 hours. Using the obtained melt-blown nonwoven fabric as the bonding layer 6 shown in FIG. 1, press molding was performed in the same manner as in Example 6 to obtain an interior material 10. Table 2 shows the butyraldehyde content and odor judgment results of the obtained meltblown nonwoven fabric, and the performance measurement results of the interior material 10.

[Comparative Example 8]

Using a copolymerized polypropylene, a melt-blown nonwoven fabric having a basis weight of 25.2 g / m ² and a thickness of 0.253 mm was obtained at a spinning temperature of 285 ° C. Using the obtained non-woven fabric as the bonding layer 6, press molding was performed in the same manner as in Example 6 to obtain an interior material 10. Table 2 shows the odor judgment results of the obtained meltblown nonwoven fabric and the performance measurement results of the interior material 10.

As shown in Table 2, use an acid value of 0.2 mgKOH / g or less The PVB pellets of the meltblown nonwoven fabrics of Examples 6 to 9 manufactured at a spinning temperature lower than 240 ° C have a low butyraldehyde content and a significant improvement in odor. The laminated body obtained by using the melt-blown nonwoven fabric as an adhesive layer exhibits excellent mechanical properties and sound absorption properties even under low-temperature / low-pressure pressing conditions. On the other hand, Comparative Example 6 using PVB particles having an acid value exceeding 0.2 mgKOH / g and Comparative Example 7 spinning at a temperature of 240 ° C or higher, the melt-blown nonwoven fabric obtained had a high butyraldehyde content, and odor was felt. gas. Moreover, the laminated body of Comparative Example 8 using a nonwoven fabric made of polypropylene had insufficient mechanical properties and sound absorption properties.

[Example 10]

Using the PVB pellets obtained in Example 1, a spunbond nonwoven fabric was produced. A spinning nozzle provided with 1,000 nozzle holes with a diameter of 0.4 mm per 1 m width was used to extrude the resin at a spinning temperature of 200 ° C. and a discharge amount of 1.0 g / min / hole, and to stretch it. Thereby, a spunbond nonwoven fabric having a fiber diameter of 15 μm, a basis weight of 30.0 g / m ² , and a thickness of 0.441 mm can be obtained. The time from the start of spinning to the generation of agglomerates is 16 hours or more. The obtained spunbond non-woven fabric was used as the bonding layer 6 as shown in Fig. 1 and laminated with the same layer structure as in Example 6, and was pressed at a pressing temperature of 140 ° C, a pressing time of 25 seconds, and a pressure of 0.2 kg / cm ² . The press molding is performed to obtain the interior material 10. Table 3 shows the butyraldehyde content and odor judgment results of the obtained spunbond nonwoven fabric, and the performance measurement results of the interior material 10.

[Example 11]

A basis weight of 30.2 g / m ² was obtained in the same manner as in Example 10, except that the same PVB particles as in Example 1 were used to form a composite fiber with a shell of PVB and a core of PP, and the spinning temperature was changed to 210 ° C. Spunbond non-woven fabric with a thickness of 0.445mm. The time from the start of spinning to the generation of agglomerates is 16 hours or more. The obtained spunbond nonwoven fabric was used as the bonding layer 6 as shown in FIG. 1, and press-molded in the same manner as in Example 10 to obtain an interior material 10. Table 3 shows the butyraldehyde content and odor judgment results of the obtained spunbond nonwoven fabric, and the performance measurement results of the interior material 10.

[Comparative Example 9]

A spunbond nonwoven fabric having a basis weight of 31.2 g / m ² and a thickness of 0.451 mm was obtained in the same manner as in Example 10, except that the same PVB pellets as in Example 1 were used and the spinning temperature was changed to 240 ° C. The time from the start of spinning to the generation of lumps was 2 hours. Using the obtained spunbond nonwoven fabric as the bonding layer 6 shown in FIG. 1, press molding was performed in the same manner as in Example 10 to obtain an interior material 10. Table 3 shows the butyraldehyde content and odor judgment results of the obtained spunbond nonwoven fabric, and the performance measurement results of the interior material 10.

[Comparative Example 10]

In the adhesive layer 6, a spider nest-shaped spunbond nonwoven fabric ("Dynac G0030" manufactured by Toyobo Co., Ltd.) having a basis weight of 30.0 g / m ² and a thickness of 0.230 mm made of modified polyester fibers was used in accordance with Example 10. The same composition and the same pressing conditions as in Example 11 were used for press molding to obtain the interior material 10. Table 3 shows the butyraldehyde content and odor judgment results of the obtained spunbond nonwoven fabric, and the performance measurement results of the interior material 10.

As shown in Table 3, an acid value of 0.2 mgKOH / g or less is used. The PVB pellets, the spunbonded nonwoven fabrics of Examples 10 and 11 manufactured at a spinning temperature below 240 ° C, had a low butyraldehyde content and a marked improvement in odor. The laminated body obtained by using the spunbonded nonwoven fabric as an adhesive layer shows excellent mechanical properties and sound absorption properties even under low temperature / low pressure pressing conditions. On the other hand, in Comparative Example 9 in which PVB particles having an acid value exceeding 0.2 mgKOH / g were spun at a temperature of 240 ° C or higher, the butyral content of the obtained melt-blown nonwoven fabric was high, and odor was felt. Moreover, the laminated body of Comparative Example 10 using a polyester nonwoven fabric had insufficient mechanical properties and sound absorption properties.

Claims (14)

A fiber comprising polyvinyl butyral having a degree of butyralization of 50 to 90% by mass and a butyral content of 15% by mass or less. For example, the fiber of claim 1 is a single fiber composed only of polyvinyl butyral, a composite fiber containing polyvinyl butyral as one of the components, or a polyvinyl butyral as one of the components Mixed fibers. A fiber assembly containing fibers as claimed in claim 1 or 2. If the fiber assembly of claim 3 is a non-woven fabric, fabric, paper or knitted fabric. A laminated body formed by bonding a plurality of layers through a bonding layer composed of a fiber assembly as claimed in claim 3 or 4. The laminated body according to claim 5, which is formed by bonding the inorganic fiber layer and the other layers through the bonding layer. The laminated body according to claim 6, wherein the inorganic fiber layer is a glass fiber layer. The laminated body according to claim 6 is obtained by adhering the inorganic fiber layer, the foam layer, and the surface material layer through the adhesive layer. A built-in material comprising a laminated body according to any one of claims 5 to 8. A method for manufacturing a fiber as claimed in claim 1 or 2, characterized in that the degree of butyralization is 50 to 90% by mass, the MFR at 150 ° C and 2.16 kgf is 0.5 to 45 g / 10 minutes, and the acid value is 0.1 A pellet made of polyvinyl butyral having a mgKOH / g or lower and a butyraldehyde content of 5 mass ppm or lower is melt-spun at a temperature of 230 ° C or lower. The manufacturing method according to claim 10, wherein the polyvinyl butyral powder having a moisture content of 5% by mass or less is put into the extruder, and at least one exhaust port is used to reduce the pressure to less than 0.008 MPa to remove the volatile portion. Melt-knead at a temperature of 220 ° C. or lower to obtain pellets, and then use the pellets for melt-spinning. The manufacturing method according to claim 10, wherein the fiber is a long fiber, and a winding speed during melt spinning is 2000 to 5000 m / min. The manufacturing method according to claim 12, wherein the melt-spun fiber is temporarily cooled to a temperature below the glass transition point, and then continuously heated and stretched as it is, and then an oil agent is added and then wound up. The manufacturing method according to claim 13, wherein when the melt-spun fiber is temporarily cooled to a temperature below the glass transition point, the blowing temperature is 20 to 30 ° C and the relative humidity is 20 at a speed of 0.4 to 1.0 m / s. ~ 60% cooling air.