JP2007168292A - Base material for interior trim - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a base material for an interior trim having excellent noise-absorbing properties in a conversation frequency range with a reduced thickness while maintaining practical characteristics as an interior trim such as flexural rigidity, dimensional stability and heat moldability. <P>SOLUTION: The base material for an interior trim is manufactured by overlaying a multilayered skin material on one side of a polypropylene resin foamed laminate sheet. The multilayered skin material is constituted by sandwiching a film having through-holes for air permeability between a knit cloth or a nonwoven cloth skin material and a non-sound-absorbing soft urethane. The polypropylene resin foamed laminate sheet is constituted by overlaying reinforcing layers, particularly a composite sheets composed of an inorganic fiber sheet and a polyethylene resin film on both sides of a polypropylene resin foamed layer having a high rate of continuous cells. The base material for the interior trim having above properties is thus obtained. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a base material for interior material used in a room such as a house, a vehicle or an aircraft. More specifically, the present invention relates to an interior material base material that is excellent in lightness, rigidity, heat resistance, and thermoformability and that has excellent sound absorption when placed in a site that requires design.

  Conventionally, as automobile ceiling materials, urethane foam laminated on a base material mainly composed of thermoplastic resin foam, or styrene-maleic anhydride copolymer on both sides of a foamed layer of styrene-maleic anhydride copolymer. A sheet formed by laminating a non-foamed layer into a desired shape is widely used. These automobile ceiling materials are characterized by light weight, high heat insulation, and excellent moldability.

  However, the conventional automobile ceiling materials as described above, when exposed to a high temperature for a long time, have insufficient heat resistance, so that the front part hangs down due to its own weight (heat sag) and deformation occurs. There was a thing. For example, in the case of an automobile ceiling material, the front part is directly exposed to sunlight, so that the temperature rises to around 100 ° C. and the amount of deformation of the ceiling material increases.

  Therefore, in order to solve these problems, automobile ceiling materials based on composite materials of inorganic glass fibers and polyolefin resins have been used (see Patent Documents 1 and 2). However, although these composite materials can maintain the quality of heat resistance, there is a problem that the weight cannot be reduced and the cost is increased.

  In order to reduce the weight, a molded ceiling base material in which a reinforcing material containing inorganic fibers is laminated on a polypropylene resin foam sheet has also been proposed (see Patent Document 3). However, although improvement in rigidity and heat resistance is recognized, it cannot be said that securing rigidity at a heat-resistant evaluation temperature of 80 to 100 ° C. and control of heat-resistant deformation are sufficient, and dimensional accuracy to interior ceiling materials In response to the demand for improvement, it has been difficult to ensure sufficient physical properties in terms of shrinkage after molding and dimensional stability at high temperatures.

  Further, various forms of sound absorbing materials have been proposed as interior materials in order to pursue quietness in a demarcated place defined as a room, for example, a room of a house, a vehicle, or an aircraft. These sound-absorbing materials need to satisfy various required qualities for each part used in addition to sound-absorbing properties. For example, if vehicle interior materials are mentioned, lightness, rigidity, design, heat resistance, thermoforming And cost.

  As a base material satisfying these functions, a base material (for example, Patent Document 4) in which glass fiber and thermoplastic fiber or resin are combined, and a foamed layer made of urethane sandwiched with a non-foamed layer such as a glass mat. Urethane base materials (for example, Patent Document 5) have been proposed.

  However, there is a problem in lightness, workability, etc. in the base material in which glass fiber and thermoplastic fiber or resin are combined. In the foamed urethane base material, recyclability and volatility by using urethane resin. There were problems such as generation of organic compounds (VOC) and weather resistance.

  Furthermore, since it is necessary to increase the thickness of the base material in order to increase the sound absorption in the middle frequency range (for example, 1000 to 2000 Hz) where the most noise reduction is required in the room quietness, the cost, space, and molding are required. There was a problem with sex.

  Apart from the proposal of the above-mentioned base material having sound absorbing properties, it has been proposed to provide sound absorbing properties by laminating urethane or ultrafine fibers that function as a sound absorbing material on the base material. For example, a vehicle interior material (see Patent Document 6) in which low-breathing urethane is provided as a sound absorbing layer between the base material and the skin, or a urethane slab or extra fine fiber is laminated as a sound absorbing skin material on a closed cell foam laminated base material. (See Patent Document 7). However, these are all expensive because they use a material in which the ventilation resistance (air permeability) is highly controlled.

  Further, in order to satisfy the above performance as much as possible, a sound absorbing material including a felt sound absorbing material (see Patent Document 8) in which a breathable film is installed in a layer structure inside the felt material, and a hard layer having a specific ventilation resistance. A composite (see Patent Document 9) has been proposed. However, any of them is insufficient for use in a part that is required to be ultralight and low cost. In addition, when the interior material is thin (thickness is about 10 mm or less), it is difficult to control with only the ventilation resistance in order to obtain high sound absorption performance in an arbitrary range (for example, about 4000 Hz or more in normal incident sound absorption coefficient measurement). .

  Further, for the same purpose, a sound absorbing structure (see Patent Document 10) formed by laminating a film in which a through hole is formed has been proposed. Even if the cover layer is laminated, when it is post-processed, such as molding, the non-adhered part of the cover layer, that is, the floating part on the through-hole part of the film, is noticeably impaired. Such problems occur.

As described above, interior materials are inexpensive, have good processability, have excellent lightness, rigidity, heat resistance, thermoformability, and design, and have high sound absorption performance even when the thickness is small and stable. Therefore, it has been difficult to provide sound absorption performance.
JP-A-1-285432 JP 7-68689 A JP 2003-34192 A JP 10-315396 A JP-A-9-277415 JP 2002-200902 A JP 55-11947 A Japanese Patent No. 3516372 Japanese Patent No. 3359645 JP 2002-82671 A

  An object of the present invention is to provide a base material for an interior material that is inexpensive and has good workability, is excellent in lightness, rigidity, heat resistance, thermoformability and design, and has high sound absorption even when the thickness is small. And

As a result of intensive studies, the present inventors have found the following (i) to (iii), and have provided practical materials as interior materials, and provided a substrate for interior materials excellent in light weight and sound absorption. It was.
(I) By interposing a film provided with air permeability by providing a through hole between a skin material made of knitted fabric or nonwoven fabric and non-sound absorbing soft urethane, it is inexpensive and has good workability, light weight, heat A multilayer skin material that is excellent in moldability and designability and that has high sound absorption performance especially in a high frequency region even when the thickness is small in the room.
(Ii) A flexible foamed resin sheet with a high foaming ratio and open cell ratio (low compression gradient) is used as the foamed layer, and both sides of the foamed layer have high rigidity (high tensile elastic gradient) and good moldability. Layered with a composite sheet consisting of an inorganic fiber sheet and a polyethylene resin film in particular, which satisfies the lightness, rigidity, heat resistance, and thermoformability as an interior material, and has a high open cell ratio. Excellent sound-absorbing performance, especially in the middle frequency range, can be achieved by the plate / membrane vibration absorption mechanism from the laminated structure of the stiff reinforcing layer.
(Iii) By laminating the multilayered skin material described in (i) and the foamed laminated sheet for interior material described in (ii), it is excellent in lightness, rigidity, heat resistance, thermoformability, and designability, and medium to high It is possible to obtain a base material for interior material having excellent sound absorption in the frequency domain.

That is, the present invention
A base material for interior material in which a multilayer skin material B is laminated on one side of a polypropylene resin foam laminated sheet (A), wherein the multilayer skin material (B) is provided with air permeability by providing a through hole. A multilayer skin material in which the film (b3) is interposed between a skin material (b1) made of a knitted fabric or a nonwoven fabric and a non-sound absorbing soft urethane (b2), and the polypropylene resin foam laminated sheet ( A) is a polypropylene resin foam laminated sheet in which a reinforcing layer (a2) is laminated on both surfaces of a polypropylene resin foam layer (a1) having an open cell ratio of 55 to 98%. Substrate (claim 1),
The base material for interior material according to claim 1, wherein the expansion ratio of the polypropylene resin foam layer (a1) in the polypropylene resin foam laminate sheet (A) is 10 to 20 times. Item 2),
The compression gradient at 23 ° C of the polypropylene resin foam layer (a1) in the polypropylene resin foam laminate sheet (A) is 1000 to 30000 g / cm ² / cm ² , A base material for interior material according to claim 2 (Claim 3),
The tensile elastic gradient at 23 ° C of the reinforcing layer (a2) in the polypropylene resin foam laminated sheet (A) is 100 to 500 MPa · mm, according to any one of claims 1 to 3. The base material for interior material according to claim 4 (Claim 4),
The interior material according to any one of claims 1 to 4, wherein the reinforcing layer (a2) in the polypropylene resin foam laminated sheet (A) is a composite sheet comprising an inorganic fiber sheet and a thermoplastic resin film. Base material (claim 5),
The interior material according to any one of claims 1 to 5, wherein the reinforcing layer (a2) in the polypropylene resin foam laminated sheet (A) is a composite sheet comprising an inorganic fiber sheet and a polyethylene resin film. Substrate (claim 6),
In the polypropylene resin foam laminated sheet (A), the composite sheet comprising the inorganic fiber sheet and the polyethylene resin film as the reinforcing layer (a2) has a structure in which the inorganic fiber sheet is sandwiched between a plurality of polyethylene resin films. The interior material base material according to claim 6 (claim 7),
The base for interior material according to claim 6 or 7, wherein the resin constituting the polyethylene resin film in the polypropylene resin foam laminated sheet (A) is a linear low density polyethylene resin. Material (claim 8),
The non-absorbing soft urethane (b2) in the multilayer skin material (B) has a ventilation resistance of 100 N · s · m ⁻³ or less and a density of 0.03 g / cm ³ or less. The interior material base material according to any one of claims 1 to 8 (claim 9),
The base material for interior materials according to any one of claims 1 to 9, wherein the thickness of the non-sound absorbing soft urethane (b2) in the multilayer skin material (B) is 2 mm or more. 10),
The opening ratio of the film (b3) provided with a through hole and having air permeability in the multilayer skin material (B) is 0.9 to 25%, any one of claims 1 to 10, A base material for interior materials according to claim 11 (claim 11),
The average pore diameter of the film (b3) provided with a through hole in the multilayer skin material (B) and having air permeability is an equivalent circle diameter of 1.0 to 4.9 mmφ. The base material for interior materials in any one of -11 (Claim 12),
The multilayer skin material (B) has a ventilation resistance of 50 to 700 N · s · m ⁻³ , and the total ventilation of the multilayer skin material B. The substrate for interior material according to any one of claims 1 to 12, wherein the resistance is 70 to 2500 N · s · m ^-3 (claim 13),
The base material for interior materials (Claim 14) and the multilayer skin material according to any one of Claims 1 to 13, wherein the basis weight of the multilayer skin material (B) is 290 g / m ² or less. In B), a film (b3) provided with air permeability by providing a through hole, a skin material (b1) made of a knitted fabric or a non-woven fabric, and a non-sound-absorbing soft urethane (b2) are interposed via an adhesive layer. The base material for interior materials according to any one of claims 1 to 14, wherein the base material is integrated by heat fusion (claim 15).
About.

  The base material for interior material of the present invention is a base material for interior material in which a multilayer skin material (B) is laminated on one side of a polypropylene resin foam laminated sheet (A), and the multilayer skin material (B) In addition, a film (b3) provided with air permeability by providing a through hole is a multi-layer skin material interposed between a skin material (b1) made of a knitted fabric or a nonwoven fabric and a non-sound absorbing soft urethane (b2), And the composite sheet which consists of a polypropylene resin foaming laminated sheet (A) on both surfaces of a polypropylene resin foam layer (a1) with a high open cell ratio, a reinforcement layer (a2), especially an inorganic fiber sheet and a polyethylene resin film By maintaining the practical characteristics of the interior material such as bending rigidity, dimensional stability, and heat formability, it is possible to reduce the thickness of the speech frequency range (medium to high frequency range). It has excellent sound absorption.

  The base material for interior material of the present invention is a base material for interior material in which a multilayer skin material (B) is laminated on one side of a polypropylene resin foam laminated sheet (A), and the multilayer skin material (B) Is a multilayer skin material in which a film (b3) provided with air permeability by providing a through hole is interposed between a skin material (b1) made of a knitted fabric or a nonwoven fabric and a non-sound absorbing soft urethane (b2). In addition, the polypropylene resin foam laminate sheet (A) is a polypropylene resin foam laminate sheet in which a reinforcing layer (a2) is laminated on both surfaces of a polypropylene resin foam layer (a1) having a high open cell ratio.

  In the present invention, by laminating the multilayer skin material (B) on one side of the polypropylene resin foam laminated sheet (A), it is excellent in lightness, rigidity, heat resistance, thermoformability, designability, A base material for interior material having excellent sound absorption in a medium to high frequency region can be obtained.

  The multilayer skin material (B) according to the present invention comprises a film (b3) provided with air permeability by providing through holes, a skin material (b1) made of a knitted fabric or a nonwoven fabric, and a non-sound absorbing soft urethane (b2). By interposing between them, it is inexpensive and has good workability, is excellent in lightness, thermoformability and design, and can exhibit high sound absorption performance especially in a high frequency region even if the thickness is small in the room.

  The sound absorption performance of the multilayer skin material (B) according to the present invention includes the aperture ratio of the film (b3) provided with air permeability by providing through holes, the thickness of the non-sound absorbing soft urethane (b2), and the multilayer skin material ( B) It can be controlled by the total ventilation resistance of the whole.

Density of the skin material consisting of a knitted fabric or nonwoven fabric of the present invention (a1) is preferably from ^{0.01~0.50g / cm 3, 0.05~0.25g / cm} 3 is more preferable. When the density of the skin material is less than 0.01 g / cm ³ , the designability or wear resistance tends to be inferior, and when it exceeds 0.50 g / cm ³ , the lightness, workability, moldability, etc. tend to be inferior. is there.

    0.5-3 mm is preferable, as for the thickness of the skin material (a1) which consists of a knitted fabric or a nonwoven fabric in this invention, 1-3 mm is more preferable, and 1.2-2.4 mm is further more preferable. When the thickness of the skin material is less than 0.5 mm, problems such as see-through occur, and the design property tends to decrease. When the thickness exceeds 3 mm, problems may occur in lightness, moldability, or cost.

Basis weight of the skin material consisting of a knitted fabric or nonwoven fabric of the present invention (a1) is preferably from 50 to 500 g / m ^2, more preferably 50 to 200 g / m ^2, cost, in terms of practicality and lightweight, 80 130 g / m ² is particularly preferred.

  Of the skin material (b1) made of knitted fabric or nonwoven fabric in the present invention, the nonwoven fabric skin material may be composed of any material as long as it has practical properties as a general skin material for interior materials. Examples of the material constituting the nonwoven fabric include fiber bodies made of synthetic fibers, semi-synthetic fibers, natural fibers, or recycled fibers. More specifically, from synthetic fibers such as polyester, polypropylene, polyamide (nylon), polyurethane, polyacryl, polyacrylonitrile, modacrylic, natural fibers such as wool, cotton, hemp, cellulose, and recycled fibers such as rayon The nonwoven fabric which becomes is used suitably.

  Since the nonwoven fabric skin material in the present invention is a design surface, the material constituting the nonwoven fabric in the present invention is preferably excellent in wear resistance, and better in formability when placed in a site to be molded. . The non-woven skin material may be a combination of the above materials. Among these, as the nonwoven fabric skin material, a nonwoven fabric made of polyethylene terephthalate fibers is particularly preferable from the viewpoint of cost and thermoformability.

  The nonwoven fabric skin material in the present invention is produced by the same method as that for producing a general nonwoven fabric. Depending on the manufacturing method, a bonded binder-bonded fabric, a needle punched fabric, a spunbonded fabric, a spray fiber fabric, or a stitchbonded fabric can be used.

  When the nonwoven fabric skin material of the present invention is manufactured by needle punching, by adjusting the number of punching and the needle stroke, the entanglement between fibers is increased to increase the rigidity of the fibrous body, thereby improving the design and wear resistance. Can be granted.

  As the non-woven skin material in the present invention, an adhesive (binder resin) and / or a heat-fusible fiber (low-melting fiber) having a function as a binder between fibers is appropriately mixed with the material, and chemically or It can be used by being entangled by a mechanical method.

  Examples of the binder resin in the present invention include water-soluble, solvent-soluble, viscose liquid, emulsion, and synthetic resin powder. The emulsion type is preferable from the viewpoint of water resistance, flexibility, and workability. As the emulsion type, acrylonitrile / butadiene latex, styrene / butadiene latex, acrylate / latex, vinyl acetate latex and the like may be used. These may be used alone or as a mixture of two or more. Good.

  Examples of the heat-fusible fiber (low melting point fiber) in the present invention include polyethylene, polypropylene, low melting point (for example, about 60 to 180 ° C., preferably 110 to 160 ° C.) polyester (hereinafter simply referred to as “low melting point polyester”). Or a core-sheath type fiber having a low melting point polyolefin or polyester fiber as a sheath component and a high melting point polyester fiber as a core component. Among these, when polyethylene terephthalate is used as the synthetic fiber constituting the nonwoven fabric skin material, from the viewpoint of recyclability, a low melting point (for example, about 60 to 180 ° C., preferably 110 to 160 ° C.) polyester fiber ( Particularly preferred are core-sheath fibers).

  The nonwoven fabric skin material of the present invention can be further provided with designability or wear resistance by resin coating on the design surface.

  Of the skin material (b1) made of knitted fabric or nonwoven fabric in the present invention, examples of the knit that is a knitted fabric skin material include tricot, double russell, velvet, etc., and those used for automobile interior materials. Any of them can be used.

  The knit in the present invention uses a single yarn and is knitted by continuously looping the loop continuously and has a structure in which the loops are gathered. It is difficult to wrinkle or crease, has excellent heat retention due to its porosity, has a low specific gravity, and can have a light finish for a sense of volume. The knit is finished in various textures depending on how it is knitted, and in particular the tricot is a loop that is continuously connected in the thickness direction of the fabric. Since it is excellent in finish and fit, it is particularly preferably used for interior materials.

  As the non-sound-absorbing soft urethane (b2) in the present invention, any material can be used as long as it is generally used as an interior material and has cushioning properties, but their density and ventilation resistance are appropriately combined. Thus, it is possible to control the sound absorption frequency range to be improved in the sound absorption performance to a desired sound absorption frequency range.

  As the non-sound absorbing soft urethane (b2) in the present invention, in view of lightness and cost, it is preferable that it plays a role as an air layer as much as possible against sound waves. That is, as the non-sound absorbing soft urethane (b2) in the present invention, the smaller the density and the smaller the airflow resistance, the more preferable.

Specifically, the density of the non-sound-absorbing flexible polyurethane in the present invention (b2) is preferably from 10 to 30 kg / m ^3, from the viewpoint of weight and cost, 13~20kg / m ³ is especially preferred. If the density of the non-sound-absorbing soft urethane (b2) is less than 10 kg / m ³ , the interfacial adhesion with the film (b3) provided with air permeability by providing a through hole may be reduced to a value that does not meet the practical characteristics. The moldability tends to be inferior. When the density exceeds 30 kg / m ³ , the lightness and cost tend to be inferior.

Airflow resistance of the non-sound-absorbing flexible polyurethane in the present invention (b2) is preferably from 10~100N · s · m ^-3, and more preferably ^{25~70N · s · m -3, 30~60N} · s · m -3 Is more preferable. When the ventilation resistance of the non-sound absorbing soft urethane (b2) is less than 10 N · s · m ⁻³ , the porosity is too high, so that the interfacial adhesion with the film (b3) is lowered to the extent that it does not meet the practical characteristics. Or shape stability tends to be inferior. When the ventilation resistance is larger than 100 N · s · m ⁻³ , the lightness and cost tend to be inferior.

  The airflow resistance in the present invention is an index indicating the difficulty of permeation of air into the material. The airflow resistance can be calculated from the following equation by measuring the air permeability by the Frazier test defined in JIS L1096. . Here, ΔP represents the pressure difference before and after the target material at the time of measurement.

  The thickness of the non-sound absorbing soft urethane (b2) in the present invention is preferably 2 to 10 mm, and particularly preferably 3 to 7 mm from the viewpoints of lightness, cost, and sound absorption. When the thickness of the non-sound absorbing soft urethane (b2) is less than 2 mm, sufficient sound absorbing performance is not exhibited, and the sound absorbing effect of the structure tends to be small. When the thickness exceeds 10 mm, it is inferior in lightness and cost, and when used in a part to be molded, it tends to be inferior in shape followability.

  The opening ratio of the film (b3) provided with through holes in the present invention is preferably 0.9 to 25%, more preferably 5 to 25%, and still more preferably 8 to 22%. When the aperture ratio of the film (b3) provided with air permeability by providing a through hole is less than 0.9%, the film tends to fail to obtain desired sound absorption characteristics because it functions as a reflector for sound waves. Yes, when the aperture ratio exceeds 25%, the surface area of the design surface is reduced and the surface material is lifted, resulting in design problems and interface adhesion problems as practical characteristics. Tend to.

The aperture ratio is an index of how many through holes are present in the film plane, and can be measured by determining the diameter (area) and number of the through holes.
In general, the aperture ratio can be calculated as follows.
(A) A film (b3) provided with a through hole and provided with air permeability is photographed together with a scale to obtain a film stretched at an appropriate magnification.
(B) An OHP sheet is placed on the obtained photograph, and the portion corresponding to the through hole is painted with black ink and copied (primary processing).
(C) The primary processing image is taken into an image processing apparatus (for example, PIAS-II, manufactured by Pierce Co., Ltd.), and whether or not the dark color portion and the light color portion are painted with black ink is identified.
(D) Using “FRACTAREA (area ratio)” in the image analysis calculation function, the area ratio of the through holes in the entire image is obtained by the following equation.

  However, since all the through holes in this example were provided in a circle, the average value of the diameters of the through holes in the 30 mm × 30 mm film (all used in the examples are circles) and the number of through holes. And the aperture ratio was determined from the following equation.

  The average hole diameter (diameter) of the through holes of the film (b3) provided with the through holes in the present invention is preferably 1.0 to 4.9 mmφ as an equivalent circle diameter, and is preferably 2.0 to 4.9 mmφ is more preferable, and 2.5 to 4.9 mmφ is more preferable. When the hole diameter of the through hole is less than 1.0 mmφ, the film acts as a reflector for the sound wave, so that there is a tendency that a desired sound absorption characteristic cannot be obtained. When the diameter of the through-hole exceeds 4.9 mmφ, the surface area of the surface material becomes smaller and the surface material floats, which causes problems of design and practical properties. Tend to occur.

  The equivalent circle diameter of the through hole is a diameter corresponding to the case where the through hole is a circle from the area of the through hole, and can be measured by determining the area of the through hole. For example, measurement can be performed by using the image analysis calculation function.

  In the present invention, as a method of providing a through-hole in the film, for example, a method of melting and opening by passing through a hot needle (roller), a method of opening mechanically by punching, it is more common to use a hot needle. It is.

Ventilation resistance of a film to have a breathability is provided a through-hole in the present invention (b3) is preferably from 50~700N · s · m ^-3, and more preferably 100~500N · s · m ^-3, 150~ 500 N · s · m ⁻³ is more preferable. When the airflow resistance is less than 50 N · s · m ⁻³ , sound waves are transmitted in the same manner as when there is no film, and thus there is a tendency that desired sound absorption characteristics cannot be obtained. When the airflow resistance exceeds 700 N · s · m ⁻³ , it tends to be unable to obtain desired sound absorption characteristics because it acts as a reflector for sound waves.

  As a material of the film (b3) provided with a through hole in the present invention and having air permeability, for example, when the laminate for interior material is disposed at a site to be processed, from the workability, It is preferable to use a film made of a plastic resin. Examples of the resin constituting the resin film include polyethylene resins, polypropylene resins, and polyolefin resins such as copolymers or modified products thereof, polystyrene resins, polyester resins, polyamide resins, and polycarbonate resins. Examples thereof include a resin, a polyvinyl chloride resin, a copolymer thereof, and a mixture of a thermoplastic elastomer. These films may be a single layer or a multilayer film in which a plurality of films are combined.

  Among these, from the viewpoint of low cost and moldability, a single-layer resin film made of a polyethylene resin, a polypropylene resin, a polyamide resin, a polyester resin, and a copolymer or a modified product thereof is preferable.

  As thickness of the film (b3) which provided the through-hole in this invention and gave air permeability, 10-200 micrometers is preferable and 20-40 micrometers is more preferable. If the thickness of the film (b3) provided with air permeability by providing a through-hole exceeds 200 μm, the lightness tends to decrease and the moldability tends to decrease. If the thickness is less than 10 μm, There is a tendency to break.

  The film (b3) provided with a through-hole in the present invention to have air permeability is composed of a skin material (b1) made of a knitted fabric or a non-woven fabric and a non-sound absorbing soft urethane (b2) from the viewpoint of practical characteristics and sound absorption. Need to be integrated.

  As a method of interposing and integrating the film (b3) provided with air permeability by providing a through hole in the present invention between the knitted fabric skin material or the nonwoven fabric skin material (b1) and the soft urethane (b2), Examples thereof include a method using an adhesive, a needle punching process generally used for processing a nonwoven fabric, a method by heat fusion of the film itself, and a method in which the above methods are combined.

  Examples of the adhesive include, for example, an epoxy adhesive, a silicone adhesive, a urethane adhesive, and a thermoplastic resin latex. It is also effective to improve the adhesion by applying corona treatment to the film (b3) provided with air permeability by providing through holes. When heat-sealing, it is preferable to heat-seal using a film made of polyethylene resin or polypropylene resin (including a copolymer or a modified product thereof).

The total air flow resistance of the multilayer skin material (B) in the present invention is preferably from 70~2500N · s · m ^-3, and more preferably 280~2000N · s · m ^-3. Outside this range, the air in the vicinity of the through-hole portion of the film cannot vibrate efficiently, and high sound absorption performance may not be expected. That is, if the total airflow resistance of the multilayer skin material (B) is less than 70 N · s · m ⁻³ , the sound wave tends to be attenuated because it passes without resistance, and if it exceeds 2500 N · s · m ⁻³ , Has a tendency that high sound absorption performance cannot be expected because it becomes difficult to penetrate into the material.

  The polypropylene resin foam laminated sheet (A) in the present invention has a high open cell ratio and is flexible (has a large tensile elastic gradient) on both sides of a flexible (small compression gradient) polypropylene resin foam layer (a1). By laminating the reinforcing layer (a2) with good moldability, while satisfying the lightness, rigidity, heat resistance, and thermoformability as the interior material base material, the laminated structure uses a plate / membrane vibration absorption mechanism. In particular, excellent sound absorbing performance can be expressed in the middle frequency range.

  As the polypropylene resin foam layer (a1) in the polypropylene resin foam laminate sheet (A) used in the present invention, for example, a linear polypropylene resin (hereinafter, this polypropylene resin is referred to as “raw material polypropylene resin”). Resin) (which may be referred to as “resin”) that has been introduced with a long chain branch by irradiation with an electron beam (for example, HMS-PP manufactured by Sun Allomer Co., Ltd.), or a raw material polypropylene resin, isoprene monomer The base resin is preferably a modified polypropylene resin obtained by melt-kneading a radical polymerizable monomer such as divinylbenzene and a radical polymerization initiator.

  Among these, a foamed sheet having a beautiful appearance and excellent heat moldability is obtained by using a modified polypropylene resin obtained by melting and kneading a raw material polypropylene resin, an isoprene monomer and a radical polymerization initiator as a base resin. Can be easily obtained.

  A modified polypropylene resin using an isoprene monomer used as a base resin for a polypropylene resin foam layer (primary foam sheet) (a1) used in the present invention is disclosed in, for example, JP-A-11-172016. , Etc. can be obtained by the method described in the above. Furthermore, a method for producing a polypropylene resin foam layer (a1) using a modified polypropylene resin obtained by melt-kneading a polypropylene resin, an isoprene monomer and a radical initiator is disclosed in, for example, JP-A-11-228726. No. 11, JP-A-11-349722, JP-A 2000-109591 and the like.

  In the present invention, the polypropylene-based resin foam layer (a1) has a high open cell ratio, so that the foam layer (a1) itself exhibits sound absorbing performance, and the flexibility is increased. The plate / membrane vibration of the stiffened reinforcing layer is likely to occur, and high sound absorption performance can be exhibited.

The open cell ratio of the polypropylene resin foam layer (a1) in the present invention is preferably 55 to 98%, more preferably 70 to 95%. When the open cell ratio of the polypropylene resin foam layer (10) is less than 55%, the foam layer becomes rigid, and even if a high-strength reinforcing layer is laminated, a good plate / membrane vibration absorption mechanism does not appear and is good There is a tendency that the sound absorption performance is not obtained. On the other hand, when the open cell ratio exceeds 98%, the bending rigidity of the foam layer is extremely lowered, and even if a highly rigid reinforcing layer is laminated, there is a possibility that the practical properties as a base material for interior materials may not be satisfied. .
The open cell ratio of the polypropylene resin foamed layer in the present invention is measured and calculated according to ASTM D-2859, and then the open cell ratio (%) = 100−closed cell ratio (%). The value calculated by

  As a method of achieving an open cell ratio of 55 to 98% in the polypropylene resin foam layer (a1), for example, the following operation may be employed in the extrusion foaming process or the subsequent mechanical processing process. it can.

  In the extrusion foaming process, for example, (a) the temperature conditions in the extruder, (b) the amount of the foaming agent, and (c) the resin having lower heat resistance (lower glass transition temperature Tg or melting point Tm) than the polypropylene resin. The mixing amount may be adjusted. More specifically, regarding (A), by setting the resin temperature during extrusion to the high temperature side, an open cell layer can be provided as a whole in the thickness direction of the sheet. Regarding (b), if the foaming agent press-in amount is set to 5 to 10 parts by weight with respect to 100 parts by weight of the polypropylene resin, 1.5 to 2 times the normal closed cell polypropylene resin foam layer production time Good. However, if the foaming agent press-fitting amount is too large, plasticization proceeds and shear heat generation between the polymers is less likely to occur, so that the open cell ratio may decrease. Regarding (c), a low melting point polyolefin such as linear low density polyethylene (hereinafter sometimes referred to as LLDPE) may be mixed in an amount of 1 to 20 parts by weight with respect to 100 parts by weight of the polypropylene resin. In addition, you may combine these (A)-(C).

  Further, as the mechanical processing step after the extrusion foaming step, for example, operations such as a compression press, drilling, and slit processing are effective.

  The expansion ratio of the polypropylene resin foam layer (a1) in the present invention (sometimes referred to as “primary expansion ratio”) is preferably 10 to 20 times, more preferably 12 to 18 times. When the expansion ratio of the polypropylene resin foam layer is less than 10 times, the polypropylene resin foam layer becomes rigid, and even if a highly rigid reinforcement layer (a2) is laminated, a good plate / membrane vibration absorption mechanism is exhibited. Therefore, there is a tendency that good sound absorption performance cannot be obtained. On the other hand, when the foaming ratio exceeds 20 times, the bending rigidity of the foamed layer is extremely reduced, and even if a highly rigid reinforcing layer (a2) is laminated, the practical properties as a base material for interior materials may not be satisfied. . In addition, the expansion ratio in this invention is the value measured based on JISK7222.

The compression gradient of the polypropylene resin foam layer (a1) in the present invention is preferably 1000 to 30000 g / cm / cm ² , more preferably 1000 to 20000 g / cm / cm ² , and further preferably 2500 to 20000 g / cm / cm ^2. It is. When the compression gradient of the polypropylene resin foam layer (a1) is less than 1000 g / cm / cm ² , it tends to be difficult to maintain the structural rigidity as a base material for interior materials, while the compression gradient is 30000 g / cm ^2. When it exceeds cm / cm ² , it tends to be difficult to develop sufficient sound absorption.
The compression gradient in the present invention is one index indicating the magnitude of compression elasticity, but in the initial change portion of the stress-strain curve obtained when a compression test is performed in the thickness direction of the foam layer, a linear straight line is obtained. It is a value obtained by dividing the slope of the portion that can be regarded as the initial value, that is, the initial slope value by the cross-sectional area of the test sample (unit area, compressive load per 1 cm of strain).

  The thickness of the polypropylene-based resin foam layer (a1) in the present invention (hereinafter sometimes referred to as “primary thickness”) varies depending on the portion disposed as the interior material. -7 mm is preferable, and 3-6 mm is more preferable. When the thickness of the polypropylene resin foam layer (a1) is smaller than 3 mm, the handling property at the time of attachment to the automobile body is often deteriorated, and the bending rigidity is often lowered. On the other hand, when it is larger than 7 mm, the shape development property at the time of molding tends to be poor, or the small space property tends to be poor.

Basis weight of the foamed polypropylene resin layer (a1) in the present invention is preferably ^{150~350g / m 2, 150~250g / m} 2 is more preferable. When the basis weight of the polypropylene-based resin foam layer (a1) is less than 100 g / m ² , the bending rigidity of the foam layer tends to be lowered when trying to obtain the foaming ratio and thickness. When the weight is greater than 350 g / m ² Tends to be inferior in lightness.

  The reinforcing layer (a2) in the polypropylene resin foam laminated sheet (A) used in the present invention is used for the purpose of improving the dimensional stability, heat resistance, and rigidity of the molded article after molding, It also plays an important role in the mid-range sound absorption.

The tensile elastic gradient at 23 ° C. of the reinforcing layer (a2) in the polypropylene resin foam laminated sheet (A) in the present invention is preferably 100 to 500 MPa · mm, more preferably 100 to 400 MPa · mm, and 200 to 400 MPa · mm. mm is more preferable. If the tensile elastic gradient at 23 ° C. of the reinforcing layer (a2) is less than 100 MPa · mm, sufficient rigidity tends not to be developed, and if it exceeds 500 MPa · mm, good sound absorption tends not to be developed.
The tensile elastic gradient in the present invention is a portion that can be regarded as a linear straight line in an initial change portion of a stress-strain curve obtained when a general tensile test is performed, that is, a tensile elastic modulus Em obtained from the initial gradient. Is multiplied by the thickness d of the material.

  As the reinforcing layer (a2) in the polypropylene resin foam laminated sheet (A) in the present invention, for example, an inorganic fiber sheet in which inorganic fibers are partially bonded by a thermoplastic resin fiber binder, a thermoplastic resin film, Composite fiber sheet composed of inorganic fiber sheet, thermoplastic resin sheet containing inorganic particles such as talc and mica, composite fiber sheet composed of thermoplastic resin film and metal fiber sheet, thermoplastic resin sheet containing metal particles, etc. It is done.

  Among these, the composite fiber sheet which consists of a thermoplastic resin film and an inorganic fiber sheet is preferable from the point which is excellent in the adhesiveness with a polypropylene resin foam layer, and the dimensional stability at the time of high temperature.

  Examples of the inorganic fiber constituting the inorganic fiber sheet in the reinforcing layer (a2) in the present invention include glass fiber, carbon fiber, ceramic fiber, basalt fiber, alumina fiber, and the like. It may be used by mixing with different kinds or by stacking in multiple layers. Among these inorganic fibers, glass fibers are preferable from the viewpoint of processability, versatility, and cost.

  As the glass fiber sheet in the present invention, after glass strands are cut into a predetermined length to obtain glass chopped strands, a large number of glass chopped strands are deposited so as to be uniformly dispersed on the conveyor, The glass fiber mat that is fixed by spraying a binder resin (fiber binder) made of a thermoplastic resin emulsion and then heating and cooling, and the heat that is the binder resin (fiber binder) when the glass fiber is defibrated Any glass fiber paper obtained by dispersing in water containing a plastic resin emulsion, scooping and drying it, or so-called papermaking can be used. In addition, for example, various glass fibers such as a glass fiber nonwoven fabric in which opened glass fibers are entangled by a mechanical method such as a needle-pung method, a surface mat and a continuous strand mat manufactured by continuous glass strands, etc. Nonwoven fabrics can also be used.

  5-20 micrometers is preferable and, as for the fiber diameter of the inorganic fiber which forms the inorganic fiber sheet in this invention, 8-15 micrometers is more preferable. If the fiber diameter is thinner than 5 μm, the mechanical strength of the obtained laminated foam sheet may be insufficient, and if it is thicker than 20 μm, it may be difficult to laminate and integrate with the polypropylene resin foam sheet. is there.

  30-100 mm is preferable and, as for the fiber length of the inorganic fiber which forms the inorganic fiber sheet in this invention, 30-50 mm is more preferable. If the fiber length is shorter than 30 mm, the reinforcing effect tends to be reduced, and if it is longer than 100 mm, it may be difficult to laminate and integrate with the foam sheet.

20-150 g / m < ² > is preferable and, as for the mass (unit weight) per inorganic fiber sheet unit surface property in this invention, 30-100 g / m < ² > is more preferable. When the basis weight is lighter than 20 g / m ² , the reinforcing effect tends to decrease. When the basis weight is heavier than 150 g / m ² , the manufacturing unit price increases, and the total basis weight of the obtained foamed laminated sheet increases, resulting in lightness. There is a tendency to be damaged. Here, when the basis weight is about ²⁰ to 50 g / m ² , it is realistic to use glass fiber paper, and when it is around 100 g / m ² or more, it is realistic to use a glass mat.

  The inorganic fiber sheet in the present invention is combined from a thermoplastic resin film. The thermoplastic resin film plays a role of improving the adhesion between the polypropylene resin foam layer (a1) and the inorganic fiber sheet and the appearance of the molded body, and at the same time, by combining with the inorganic fiber sheet, the dimensions of the molded body. It plays the role of improving stability, heat resistance, rigidity, and heat moldability.

  Examples of the base resin of the thermoplastic resin film in the present invention include resins such as polyethylene, polypropylene, polybutene, nylon, and polyester. Among these, polyolefin resin films such as polyethylene and polypropylene are particularly preferable from the viewpoint of good heat fusion with the polypropylene resin foam layer. Furthermore, a polyethylene resin is particularly preferable from the viewpoint of moldability.

  That is, in the present invention, as the base resin of the thermoplastic resin film constituting the composite fiber sheet, a polyethylene resin having a heat resistance, particularly a lower melting point, is used than the polypropylene resin that is the base resin constituting the foam sheet. By doing so, strong adhesiveness without any problem in practical characteristics of the automobile interior material can be obtained by heat fusion, and residual distortion can be applied to the composite sheet without damaging the polypropylene resin foam layer (a1). Heat molding that does not occur is possible, and the appearance of the molded body can be improved. Furthermore, by combining the polyethylene resin film and the inorganic fiber sheet, the rigidity and heat resistance are improved, and the dimensional change and movement of the foamed sheet can be suppressed. The dimensional stability, heat resistance, Stiffness can be improved.

  Examples of the polyethylene resin constituting the polyethylene resin film in the present invention include high density polyethylene (HDPE), low density polyethylene (LDPE), very low density polyethylene (VLDPE), very ultra low density polyethylene (ULDPE), straight Examples include linear low density polyethylene (LLDPE) and ultra high molecular weight polyethylene (UHMWPE).

  Among these polyethylene-based resins, linear low-density polyethylene (LLDPE) has good heat-fusability with a polypropylene-based resin foam sheet, and the melting point is lower than that of the polypropylene foam sheet in terms of moldability. Is preferred.

The melting point of the polyethylene resin constituting the polyethylene resin film of the present invention is preferably at least 20 ° C. and preferably at least 30 ° C. lower than the melting point of the polypropylene resin constituting the polypropylene resin foam layer (a1). More preferred. When the difference between the melting point of the polyethylene resin and the melting point of the polypropylene resin is smaller than 20 ° C., the fiber composite sheet is heated to a temperature at which the film layer is not distorted during lamination and thermoforming of the polypropylene resin foam sheet. When this is done, the polypropylene foam sheet is damaged, that is, the air bubbles in the vicinity of the surface layer of the foam sheet break, so the resulting automotive interior material has a rough surface on the fiber composite sheet surface side. Tend to be inferior.
The melting point of the resin in the present invention was measured by differential scanning calorimetry (DSC) according to JIS K 7121. When two or more resins were used in combination, the arithmetic average value was adopted. .

  The polyethylene resin film in the present invention is disposed and laminated on one or both sides of an inorganic fiber sheet.

  In the present invention, even when the polyethylene resin film is laminated only on one side of the inorganic fiber sheet, the film is used in the heating and pressurizing step at the time of lamination with the polypropylene resin foam sheet (a1) and the inorganic fiber sheet. The polyethylene-based resin constituting the resin is melted, passes through the inorganic fiber sheet, and oozes out to the opposite side of the inorganic fiber sheet, whereby the adhesion and the appearance of the molded body can be improved. Therefore, when the polyethylene resin film is laminated only on one side of the inorganic fiber sheet, the polyethylene resin film may be laminated between the inorganic fiber sheet and the polypropylene resin foam layer, and the outside of the inorganic fiber sheet. It may be laminated.

  However, from the viewpoint of ensuring the adhesion between the polypropylene resin foam layer and the composite fiber sheet, and making the appearance of the molded body more beautiful, the inorganic fiber sheet is sandwiched between a plurality of polyethylene resin films, A structure in which polyethylene resin films are arranged and laminated on both surfaces of the inorganic fiber sheet is preferable.

  Although the thickness of the polyethylene-type resin film in this invention is not specifically limited, When arrange | positioning and laminating | stacking on both surfaces of an inorganic fiber sheet, 30-200 micrometers is preferable normally and 50-150 micrometers is more preferable. When the thickness of the polyethylene resin film is less than 30 μm, the surface property of the sheet tends to deteriorate. When the thickness is greater than 200 μm, the strength of the foamed laminated sheet is improved, but the weight reduction tends to be impaired.

In the present invention, when the polyethylene resin film is laminated only on one side of the inorganic fiber sheet, it is necessary to melt the polyethylene resin film and pass the inorganic fiber sheet when laminating with the polypropylene resin foam layer. In view of the passing resin content, the thickness of the polyethylene resin film is preferably adjusted to be thick. At this time, the mel flow rate at a load of 2.16 kg / cm ² at 230 ° C. of the polyethylene resin constituting the polyethylene resin film becomes easier to pass through the inorganic fiber sheet, and is preferably 5 to 20 g / 10 min. 7 to 15 g / 10 min is more preferable.

  Examples of the method for laminating the polypropylene resin foam layer (a1) and the reinforcing layer (a2) in the present invention include laminating by heat fusion, laminating via an adhesive, and the like.

  Furthermore, in the present invention, examples of a method for laminating the polypropylene resin foam layer, the polyethylene resin film, and the inorganic fiber sheet include the following methods. For example, [1] a polypropylene resin foam layer, a polyethylene resin film alone, and a laminate of inorganic fiber sheets are heated at a temperature equal to or higher than the melting point of the polyethylene resin film and then compressed by a press, a roll, etc. By cooling, a polypropylene resin foam laminated sheet can be obtained. [2] After a composite fiber sheet is obtained by heating a laminate of an inorganic fiber sheet and a polyethylene resin film at a temperature equal to or higher than the melting point of the polyethylene resin film and compressing and cooling with a press, a roll or the like. By laminating with a polypropylene resin foam layer, a polypropylene resin foam laminate sheet can be obtained by the same process thereafter. [3] A polyethylene resin in a molten state is extruded into a film on an inorganic fiber sheet by an extrusion lamination method, and the polyethylene resin film, the inorganic fiber sheet, and the polypropylene resin foam layer are rolled with a roll at a temperature equal to or higher than the melting point of the film. A polypropylene resin foamed laminated sheet can be obtained by compounding while applying pressure and cooling. [4] By extrusion lamination, a polyethylene resin is extruded into a film on an inorganic fiber sheet, and the polyethylene resin film and the inorganic fiber sheet and the polyethylene resin film are preliminarily laminated at a temperature equal to or higher than the melting point of the film. A polypropylene resin foam laminate sheet can be obtained by forming a composite while pressing and cooling the polypropylene resin foam layer with a roll. [5] Polyethylene resin is extruded into a film form on a composite fiber sheet in which an inorganic fiber sheet and a polyethylene resin film are laminated in advance by an extrusion laminating method, and the composite fiber sheet and the polyethylene system are heated at a temperature equal to or higher than the melting point of the film. A polypropylene resin foam laminate sheet can be obtained by forming a composite while pressing and cooling the resin film and the polypropylene resin foam layer with a roll.

  Among these laminating methods, the extrusion laminating method [3], [4] and [5] reduces the damage caused by heat of the polypropylene resin foam sheet because the molten polyethylene resin is cooled simultaneously with pressurization. It is possible and preferable.

  In the present invention, by laminating the multilayer skin material B and the polypropylene-based resin foam laminated sheet (A), it is excellent in lightness, rigidity, heat resistance, thermoformability, designability, and in a medium to high frequency range. A base material for interior material having excellent sound absorption can be obtained.

  As a method of laminating the polypropylene resin foam laminated sheet (A) and the multilayer skin material (B) of the present invention, for example, a method of pre-adhering with an adhesive or the like before shaping, a hot melt film before shaping Non-sound-absorbing soft urethane which is the surface to be bonded of the multi-layer skin material B by the anchor effect by melting and softening the polyethylene-based resin film layer which is the outermost layer of the polypropylene-based resin foam laminated sheet before or during molding Examples thereof include a method of bonding to the layer (b2).

Among these, the method of melt-softening the polyethylene-based resin film layer, which is the outermost layer of the polypropylene-based resin foam laminated sheet (A), and joining with the non-sound absorbing soft urethane layer (b2) simplifies the cost and production process. From the point of view, it is preferable.
At that time, a polyethylene-based resin film is previously pressure-bonded to the adherend surface of the non-sound-absorbing soft urethane layer (b2) with a heat roll or the like, and the soft urethane layer (b2) and the polypropylene-based foamed laminated sheet (A) The method of melt-softening and adhering polyethylene resin films is preferable in terms of enhancing the adhesive strength and the reliability of adhesion.

  The specific example of embodiment of the base material for interior materials in this invention described above is demonstrated anew based on drawing. However, the base material for interior materials of the present invention is not limited by these.

  FIG. 1 shows a configuration of a base material for interior material (30) according to one embodiment of the present invention, in which a multilayer skin material (5) is laminated on one side of a polypropylene-based resin foam laminated sheet (28). It will be. Here, the multi-layer skin material (5) has a film (3) provided with air permeability by providing a through hole between the non-woven skin material (1) and the non-sound absorbing soft urethane (2). A multilayer skin material. The polypropylene resin foam laminate sheet (28) is composed of inorganic fiber sheets (12, 14) sandwiched between polyethylene resin films (16, 18, 20, 22) on both sides of the polypropylene resin foam layer (10). It is a polypropylene resin foam laminated sheet in which a composite fiber sheet (24, 26) is formed, and the polypropylene resin foam sheet (28) and the multilayer skin material (5) are interposed via a polyethylene resin film (18). It is laminated.

  FIG. 2 shows a configuration of a base material for interior material (32) according to one embodiment of the present invention, in which a multilayer skin material (6) is laminated on one side of a polypropylene resin foam laminate sheet (28). It will be. Here, in the multilayer skin material (6), a film (3) provided with air permeability by providing a through hole is interposed between the knitted fabric skin material (4) and the non-sound absorbing soft urethane (2). A multilayer skin material (6). The polypropylene resin foam laminated sheet (28) is formed by forming composite fiber sheets of inorganic fiber sheets (12, 14) and polyethylene resin films (16, 18) on both sides of the polypropylene resin foam layer (10). It is a polypropylene resin foam laminate sheet, and the polypropylene resin foam sheet (28) and the multilayer skin material (6) are laminated via a polyethylene resin film (18).

  As a method of molding a shaped interior material from the interior material base material of the present invention, for example, an interior material base material (multilayer skin material and polypropylene resin (1) is provided in the center of a heating furnace having upper and lower heaters. Next) Method of clamping and guiding a laminate with a foamed laminated sheet), heating it to a temperature suitable for molding, secondary foaming, press-cooling with a temperature-controlled mold, and shaping Is mentioned.

  Specific examples of the molding method in the present invention include, for example, plug molding, free drawing molding, plug and ridge molding, ridge molding, matched mold molding, straight molding, drape molding, reverse draw molding, air Examples include slip molding, plug assist molding, and plug assist reverse draw molding.

  The molding temperature region of the interior material base material in the present invention is set to a temperature higher than the melting point of the polyethylene resin film combined with the inorganic fiber sheet and lower than the melting point of the constituent resin of the polypropylene resin foam layer. As a result, it is possible to obtain a favorable automotive interior material in which the secondary foamed laminated sheet is not torn even in deep drawing, and there is no appearance defect due to foam breakage of the foamed layer. Specifically, the molding temperature region is preferably 135 to 155 ° C, more preferably 140 to 150 ° C.

  Here, when the primary laminated foam sheet is subjected to secondary foaming by heating, the thickness of the secondary foam sheet is 1.1 to 4 times the thickness of the primary foam sheet before and after heating. Secondary foaming is preferable, and secondary foaming is preferably performed 1.2 to 3 times.

  As mentioned above, although the embodiment of the base material for interior materials which concerns on this invention was demonstrated variously, this invention is not limited to the above-mentioned aspect. In addition, the present invention can be implemented in a mode in which various improvements, changes, and modifications are added based on the knowledge of those skilled in the art without departing from the spirit of the present invention.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereby.

  In addition, about the numerical value used by this invention, it measures with the following measuring methods.

(Reverberation room method sound absorption rate)
In accordance with JIS A1409 “Measurement method of sound absorption coefficient of reverberation room method”, a sample of size 0.7m × 0.7m was installed on the floor with a back air layer of 0mm in a 9m ³ reverberation room manufactured by Nittobo Acoustic Engineering Co., Ltd. The reverberation time was measured at five microphone positions and three repetitions at each point. From the average value of the obtained reverberation time, the sound absorption rate was obtained by the following formula, and was set as the reverberation chamber method sound absorption rate.

In the formula, V: reverberation chamber volume = 9 m ³ , S: sample surface area = 0.49 _m ² , T _m : reverberation time (seconds) when sample is inserted, T ₀ : reverberation time (seconds) when sample is not inserted .

(Tensile elastic gradient)
Three test pieces each having a width of 50 mm and a length of 150 mm were cut out from the composite sheet used in the examples or comparative examples, and the autograph DSS-2000 manufactured by Shimadzu Corporation was used, according to JIS K7127, at 23 ° C. A tensile test was performed at a distance between chucks of 100 mm and a tensile speed of 2 mm / min to obtain a tensile elastic modulus Em (MPa).
On the other hand, the thickness d (mm) of the composite sheet was measured using a micro dial gauge (Peacock Co., Ltd.).
The tensile modulus gradient of the composite sheet was calculated by the following formula.

Measurement was performed on each test piece, and an arithmetic average value of the obtained measurement values was calculated.

(Compression gradient)
A test piece having a width of 30 mm and a length of 30 mm was cut out from the polypropylene resin foam layer obtained in the examples or comparative examples, and the compression rate was 2 mm / min using an autograph DSS-2000 manufactured by Shimadzu Corporation. A compression test was performed in the thickness direction of the foam layer. In the initial change portion of the obtained stress-strain curve, the value of the slope of the portion that can be regarded as a linear line, that is, the value of the initial slope divided by the area of the test sample (unit area, compressive load per 1 cm of strain) A compression gradient was used.
The test was conducted using three test pieces in each example and comparative example, and the arithmetic mean value of the obtained measured values was calculated.

(Bending elastic gradient)
The bending elastic gradient was evaluated as an index of bending stiffness.
In the obtained polypropylene-based foamed laminated sheet, three pieces were cut out in the length direction (MD direction) and the width direction (TD direction), respectively, and a 150 mm × 50 mm foamed laminated sheet test piece was cut out, and Auto made by Shimadzu Corporation Using graph DSS-2000, according to JIS K7171, a load is applied at a speed of 50 mm / min with a R3.2 mm wedge at the center of a span length of 100 mm with free support at both ends, and the relationship between the load and strain A curve showing was obtained.
In the initial change portion of the obtained stress-strain curve, the gradient of the portion that can be regarded as a linear line, that is, the value of the initial gradient (bending load per 1 cm of strain) was defined as the bending elastic gradient.
Measurement was performed on each test piece, and an arithmetic average value in the length direction and the width direction was calculated.

(Thickness)
For the sample, 20 thicknesses in the width direction were measured using a micro dial gauge (Peacock Co., Ltd.), and the average value of the measured values was calculated.

(Foaming ratio)
The density df of the obtained primary raw fabric was measured according to JIS K7222, and the density dp of the polypropylene-based resin was separately measured according to JIS K7112, and calculated by the formula of foaming ratio = dp / df.

(Open cell ratio)
The obtained primary material was measured according to ASTM D-2859 using a multi-pycnometer (manufactured by Beckman), and the closed cell ratio (%) was determined. It was calculated by the formula of open cell ratio (%) = 100−closed cell ratio (%).

(Ventilation resistance)
The air permeability was measured using a fragile tester specified in JIS L1096, and the air resistance was calculated by the following equation. Here, ΔP represents the pressure difference before and after the target material at the time of measurement.

(Aperture ratio)
Since all the through holes were provided in a circle, the average value of the diameters of the through holes in the 30 mm × 30 mm film (all used in the examples are circles) and the number of through holes were measured, and the following formula Thus, the aperture ratio was obtained.

  In Table 1, the structure and physical-property list | surface of the base material for interior materials of an Example and a comparative example were shown.

In addition, the description regarding each code | symbol shown in Table 1-Table 2 is as follows.
PP: Polypropylene resin PPE: Polyphenylene ether resin PE: Polyethylene resin.

Example 1
<Production of multilayer skin material>
As a nonwoven fabric skin material (b1), a nonwoven fabric (b1) manufactured by Otsuka Co., Ltd. having a thickness of 1 mm mainly composed of PET fibers, a basis weight of 130 g / m ² and a ventilation resistance of 76.2 (N · s · m ⁻³ ) -1) was used. As the flexible urethane (b2), a flexible urethane (Nisshinbo Co., Ltd., Peach Urethane C24H) having a thickness of 5 mm, a basis weight of 75 g / m ² and a ventilation resistance of 39.2 (N · s · m ⁻³ ) was used. As a film (b3) provided with air permeability by providing a through-hole, a double-sided corona treatment is applied to a 30 μm-thick linear low-density polyethylene film (TUX L-LDPE TCS # 25, manufactured by Tosero Co., Ltd.). A film having a hole diameter of 3 mmφ and a pitch of 10 mm (opening ratio of 8.2%) and a ventilation resistance of 154.7 (N · s · m ⁻³ ) is used by passing through a hot needle roll. It was. As the adhesive layer (b4), a linear low density polyethylene film having a thickness of 25 μm (TuX L-LDPE TCS # 25, manufactured by Tosero Co., Ltd.) was used.
The above materials cut out to 430 mm × 430 mm are laid in the order of (b1-1), (b3), (b2), (b4), sandwiched between metal flat plates, and weighted so that the pressure becomes 0.05 MPa. By standing in a thermostatic bath in a mounted state, the temperature in the thermostatic bath is raised from 100 ° C. to 150 ° C. at a heating rate of 5 ° C./min, and then naturally cooled (b1-1). , (B3), (b2), (b4) A multilayer skin material (B-1) was obtained in which the layers were integrated. The total ventilation resistance of the (b1-1), (b3) and (b2) layers in the multilayer skin material (B-1) was 541.3 (N · s · m ⁻³ ).

<Preparation of foam laminated sheet>
As a radical initiator for 100 parts of propylene homopolymer (linear homopolypropylene, F113G manufactured by Mitsui Chemicals, Inc., melting point 158 ° C., Mel flow rate (MFR) 0.5 g / 10 min at 230 ° C.) 0.6 parts of 2,5-dimethyl-2,5-di (t-butylperoxy) hexane was blended and mixed and stirred for 5 minutes using a ribbon blender. This mixture is supplied from a hopper of a twin-screw extruder (manufactured by Nippon Steel Works, Ltd., TEX44) at a supply rate of 50 kg / hr, and isoprene monomer is supplied from an introduction part provided in the middle of the extruder using a metering pump. A modified polypropylene resin obtained by feeding at a rate of 0.5 kg / hr (a ratio of 1.0 part per 100 parts of propylene homopolymer), extruding into a strand, and chopping the strand after water cooling. Got.
The biaxial extruder was of the same direction biaxial type, the screw diameter was 44 mmφ, and the maximum screw effective length (L / D) was 38. The set temperature of the cylinder part of this twin-screw extruder was 200 ° C. after the isoprene monomer injection, and the screw rotation speed was set to 150 rpm.
As a foam nucleating agent, 0.05 part of blend oil and 100 parts by weight of mixed resin composed of 80% of the obtained modified polypropylene resin and 20% of polypropylene resin (F113G, manufactured by Mitsui Chemicals, Inc.) 0.1 parts by weight of talc (manufactured by Nippon Talc Co., Ltd., Talcan Powder PK-S) was stirred and mixed using a ribbon blender to obtain a blend. The obtained blend was supplied to a 65-90 mmφ tandem extruder and melted in a first stage extruder (65 mmφ) set at 230 ° C., and then a blowing agent containing iso-butane as a main component <iso- Butane / n-butane = 85/15 (weight ratio)> was press-mixed with 6 parts of a total of 100 parts by weight of the modified propylene-based resin and the propylene-based resin, and the second bullet extruder (set at 190 ° C.) 90 mmφ), extruded at atmospheric pressure with a circular die at a pressure of 10 MPa, wound in a roll form on a take-up roll through a take-up roll, primary thickness 3.7 mm, primary foaming ratio 18 times, open cell ratio A polypropylene resin foam sheet having 74% and a basis weight of 195 g / m ² was obtained.

On the other hand, a glass mat with a basis weight of 100 g / m ² (manufactured by Nippon Electric Glass Co., Ltd., glass chopped strand mat 100-SH / G) and two 50 g / m ² linear low-density polyethylene films (Tosero Co., Ltd.) ), TUX L-LDPE TCS # 50, melting point 103 ° C., 115 ° C.), both rolls are heated rolls heated to 160 ° C., with clearance of 2.0 mm The glass mat / polyethylene film composite sheet was obtained by passing between rolls pressed at a pressure of 0.2 MPa.

Next, the polypropylene resin foam sheet and the glass mat / polyethylene composite sheet are respectively unrolled and superposed, and the linear low density polyethylene film surface side is used as a heat roll heated to 160 ° C. A polypropylene-based resin foam laminated sheet in which a fiber composite sheet was laminated on one side was obtained by passing the sheet surface between unrolled rolls with a clearance of 3.5 mm and a pressure of 0.2 MPa. Moreover, the same operation was repeated and the polypropylene resin foaming laminated sheet (A-1) by which the fiber composite sheet was laminated | stacked on both surfaces was obtained. The obtained polypropylene resin foam laminated sheet (A-1) had a thickness of 3.5 mm and a basis weight of 595 g / m ² .

<Preparation of interior material base material>
The multilayered skin material (B-1) and the polypropylene resin foam laminated sheet (A-1) cut out to 430 mm × 430 mm are superposed so that the polyethylene film surfaces are in contact with each other, and clamped on all sides, in a thermostatic bath at 150 ° C. For 10 minutes, take out the clamp from the thermostat, and press and mold it under the conditions of a clearance of 8.0 mm and a pressure of 0.5 MPa using a flat plate mold adjusted to 23 ° C., and the thickness is about 8.5 mm. A base material for interior material (C-1) having a thickness of 5.0 mm for the multilayer skin material (B-1) and a thickness of 3.5 mm for the polypropylene resin foam laminate sheet (A-1) was obtained.

  About the obtained base material for interior materials (C-1), the results of the tensile elastic gradient at 23 ° C. of the reinforcing layer (fiber composite sheet), the compression gradient of the foam layer, and the bending elastic gradient of the foam laminate sheet are shown in Table 1. The results of the reverberation chamber method sound absorption coefficient measurement of the interior base material are shown in Table 2 and FIG.

(Example 2)
<Production of multilayer skin material>
In the same manner as in Example 1, a multilayer skin material (B-1) was obtained.
<Preparation of foam laminated sheet>
In the same manner as in Example 1, a polypropylene resin foam laminated sheet (A-1) was obtained.
<Preparation of interior material base material>
Clamp only four sides of the polypropylene resin foam laminated sheet (A-1) cut out to 430 mm x 430 mm, heat in a thermostatic bath at 150 ° C for 10 minutes, take out from the thermostatic bath, and multilayer skin material at the time of molding Using a flat plate mold temperature-controlled at 23 ° C. by a method in which the polyethylene film surface of (B-1) and the polyethylene film surface of the polypropylene resin foam laminate sheet (A-1) are in contact with each other. By forming and pressing under conditions of a clearance of 8.0 mm and a pressure of 0.5 MPa, a thickness of about 8.7 mm [multilayer skin material (B-1) thickness 5.2 mm, polypropylene resin foam laminated sheet (A-1) Of 3.5 mm in thickness] was obtained.
Table 1 shows the results of the tensile elastic gradient of the reinforcing layer (fiber composite sheet) at 23 ° C., the compression gradient of the foamed layer, and the bending elastic gradient of the foamed laminated sheet for the obtained interior material base material (C-2). Table 2 and FIG. 3 show the results of the reverberation chamber method sound absorption coefficient measurement of the interior base material.
(Example 3)
<Production of multilayer skin material>
Instead of the non-woven skin (b1-1), the thickness is 1 mm, the basis weight is 100 g / m ^2, and the ventilation resistance is 140.2 (N · s · m), which is mainly composed of a knitted fabric skin material (b1-2). ⁻³ ) The layers (b1-2), (b3), (b2), and (b4) were integrated in the same manner as in Example 1 except that the first knit manufactured by Knit Corporation was used. A multilayer skin material (B-2) was obtained. The total ventilation resistance of the (b1-2), (b3) and (b2) layers in the multilayer skin material (B-2) was 530.2 (N · s · m ⁻³ ).
<Preparation of foam laminated sheet>
In the same manner as in Example 1, a polypropylene resin foam laminated sheet (A-1) was obtained.
<Preparation of interior material base material>
Clamping the four sides of the polypropylene resin foamed laminated sheet (A-1) and heating it in a thermostatic bath at 150 ° C. for 10 minutes, then taking it out of the thermostatic bath, and forming the multilayer skin material (B-2) with a molded attachment In a method in which the film surface and the polyethylene film surface of the polypropylene resin foam laminated sheet (A-1) are in contact with each other, a flat plate mold temperature-controlled at 23 ° C. is used to provide a clearance of 8.0 mm and 0.5 MPa. Was pressed at a pressure of By forming and pressing at a mold clearance of 8.0 mm, the thickness is about 8.7 mm [multilayer skin material (B-2) thickness 5.2 mm, polypropylene resin foam laminated sheet (A-1) thickness 3.5 mm]. The base material for interior materials (C-2) was obtained.
Table 1 shows the measurement results of the tensile elastic gradient of the reinforcing layer (fiber composite sheet) at 23 ° C, the compression gradient of the foamed layer, and the bending elastic gradient of the foamed laminated sheet for the obtained base material for interior material (C-2). Table 2 and FIG. 3 show the results of the reverberation chamber method sound absorption coefficient measurement of the interior substrate.

(Comparative Example 1)
<Production of multilayer skin material>
As a nonwoven fabric skin material (b1), a nonwoven fabric (b1) manufactured by Otsuka Co., Ltd. having a thickness of 1 mm mainly composed of PET fibers, a basis weight of 130 g / m ² and a ventilation resistance of 76.2 (N · s · m ⁻³ ) -1) was used. As the flexible urethane (b2), a flexible urethane (Nisshinbo Co., Ltd., Peach Urethane C24H) having a thickness of 5 mm, a basis weight of 75 g / m ² and a ventilation resistance of 39.2 (N · s · m ⁻³ ) was used. Double-sided corona treatment was applied to a 30 μm-thick linear low-density polyethylene film (TUX L-LDPE TCS # 25, manufactured by Tosero Co., Ltd.) as a non-breathable film (b3 ′) without through holes. The film was used.
The materials are laid out in the order of (b1-1), (b3 ′) and (b2), and the (b1), (b3 ′) and (b2) layers are integrated by the same operation as in Example 1. In addition, a multilayer skin material (B-3) having a total ventilation resistance of 4300 (N · s · m ⁻³ ) was obtained.
<Preparation of foam laminated sheet>
Modified PPE resin <manufactured by Nippon GE Plastics, Noryl EFN4230: PPE component / PS component = 70/30 (weight ratio)> so that the PPE resin component is 40 wt% and the PS resin component is 60 wt%> 57. 1 part by weight and PS resin <A & M Styrene Co., Ltd., Polystyrene G8102: PS component 100%> 42.9 parts by weight of mixed resin mixed with 100 parts by weight of talc (Nippon Talc Co., Ltd., Talcan powder PK-S) 0.32 parts by weight was stirred and mixed with a ribbon blender. The obtained blend was supplied to a 65-90 mmφ tandem type extruder, melted in a first stage extruder (65 mmφ) set at 290 ° C., and then a blowing agent iso-butane containing iso-butane as a main component. 6 parts by weight of a foaming agent <iso-butane / n-butane = 85/15 (weight ratio)> 3.6 parts by weight with respect to a total of 100 parts by weight of the mixed resin, and heated to 195 ° C. Cooled in the set second bullet extruder (90 mmφ), extruded at atmospheric pressure with a circular die at a pressure of 16 MPa, wound into a roll on a take-up roll via a take-up roll, a primary thickness of 2.3 mm, primary A modified PPE resin foam layer having an expansion ratio of 16 times, an open cell ratio of 10%, an average cell diameter of 0.15 mm, and a basis weight of 150 g / m ² was obtained.
Next, while feeding out the modified PPE foam layer from a take-up roll, methacrylic acid-modified polystyrene <A & M Styrene Co., Ltd., polystyrene G9001: PS component / methacrylic acid = 92/8 (weight ratio)> 50 parts by weight, High impact polystyrene (HIPS) <A & M Styrene Co., Ltd., polystyrene H8117: PS component / rubber component = 87.5 / 12.5 (weight ratio)> Mixed resin mixed with 50 parts by weight is melted in an extruder. Kneading (resin temperature is 245 ° C.) and extruding into a film using a T-die. On the other hand, as a nonwoven fabric for preventing abnormal noise, a water needle punch nonwoven fabric with a basis weight of 25 g / m ² <Corres from Yuho Co., Ltd. S8020), the film-like non-foamed layer in a molten state is removed from the PPE foamed layer and the water needle punch In the form of sandwich cloth laminated by binder roll to form a heat-resistant PS system having a basis weight of 150 g / m ² resin chamber outer non-foamed layer.
Further, PPE resin <Nippon GE Plastics Co., Ltd. Noryl EFN4230: PPE component / PS component so as to be 20% by weight of PPE resin component and 80% by weight of PS resin component on the back side of the laminated surface. = 70/30 (weight ratio)> 28.6 parts by weight, PS resin <A & M Styrene Co., Ltd., polystyrene G8102: PS component 100%> 66.4 parts by weight and HIPS resin <A & M Styrene Co., Ltd., H8117 > 5.0 parts by weight of the mixed resin was melt-kneaded (resin temperature 250 ° C.) with an extruder, extruded into a film using a T-die, and the weight of the modified PPE-based resin room with a basis weight of 120 g / m ² A foam layer was formed.
As described above, a modified PPE-based resin foam laminated sheet (A-3) was obtained.

<Preparation of interior material base material>
A weight ratio of 4: 6 of acrylonitrile-styrene latex (solid content 50%) and styrene-butadiene resin latex is added to the modified PPE resin indoor non-foamed layer of the modified PPE resin foam laminated sheet (A-3). Apply a polystyrene resin latex adhesive mixed at a rate of 40 g / m ² at the time of WET, and bond the coated surface and the urethane foam layer surface of the multilayer skin material (B-3) together to dry the latex. By solidifying, the modified PPE resin foam laminate sheet (A-3) and the multilayer skin material (B-3) were adhered.
This was clamped on all sides, heated for 10 minutes in a constant temperature bath at 150 ° C., taken out from the constant temperature bath, and molded at a pressure of 0.5 MPa with a clearance of 8.0 mm using a flat plate mold controlled to 23 ° C. Pressed. By forming and pressing with a mold clearance of 10.0 mm, the thickness is about 10.7 mm [the thickness of the multilayer skin material (B-3) is 4.7 mm, the thickness of the modified PPE-based resin foam laminate sheet (A-3) is 6.0 mm] The base material for interior materials (C-4) was obtained.
With respect to the obtained interior material base material (IX), the results of the tensile elastic gradient at 23 ° C. of the indoor non-foamed layer, the compression gradient of the foamed layer, and the bending elastic gradient of the foamed laminated sheet are shown in Table 1. Table 2 and FIG. 3 show the measurement results of the sound absorption coefficient of the reverberation chamber.

(Reference Example 1)
Table 2 and FIG. 3 show the measurement results of the reverberation chamber method sound absorption coefficient for the multilayer skin material A-1 alone.

(Reference Example 2)
<Production of multilayer skin material>
In the same manner as in Example 1, a multilayer skin material (B-1) was obtained.
<Preparation of foam laminated sheet>
In the same manner as in Comparative Example 1, a modified polyphenylene ether-based resin foamed laminated sheet (A-3) was obtained.
<Preparation of interior material base material>
Interior material having a thickness of about 10.7 mm [multilayer skin material (B-1) thickness 4.7 mm, modified PPE resin foam laminate sheet (A-3) thickness 6.0 mm] by the same method as Comparative Example 1. A base material (C-5) was obtained.
With respect to the obtained base material for interior material (C-5), the results of the tensile elastic gradient at 23 ° C. of the indoor non-foamed layer, the compression gradient of the foamed layer, and the bending elastic gradient of the foamed laminated sheet are shown in Table 1. The measurement results of the reverberation chamber method sound absorption coefficient of the substrate are shown in Table 2 and FIG.

  As can be seen from Table 1 and FIG. 3, the interior material base material (Example) of the present invention is more air-permeable than the conventional interior material base material composed of a modified PPE resin foam layer having a low open cell ratio. Compared to a system using a multi-layer skin material in which a film that does not have a property is not interposed between a knitted fabric or a non-woven skin material and a non-sound-absorbing soft urethane (Comparative Example 1), Sound absorption performance for ensuring quietness, that is, excellent sound absorption performance in the vicinity of 1000 to 2000 Hz in reverberation room method sound absorption coefficient measurement. Polypropylene with a high open cell ratio is also used when using a multi-layer skin material in which a film provided with air permeability by providing a through hole is interposed between a knitted fabric or non-woven skin material and a non-sound absorbing soft urethane. By using a foamed laminated sheet having a resin-based resin foam layer, compared to a system using a base material for interior materials made of a modified PPE resin foam layer having a low open cell ratio (Reference Example 2), the sound absorption performance is improved. In particular, the sound absorbing performance for ensuring the quietness of the room, that is, the sound absorbing performance in the vicinity of 1000 to 2000 Hz in the reverberation chamber method sound absorption coefficient measurement.

It is a partial section explanatory view showing one embodiment of a base material for interior materials concerning the present invention. It is a partial section explanatory view showing one embodiment of a base material for interior materials concerning the present invention. It is a graph which shows the measured value of the reverberation room method sound absorption coefficient of the base material for interior materials which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nonwoven fabric skin material 2 Non-sound-absorbing soft urethane 3 Film which provided the air permeability by providing the through-hole 4 Knitted fabric skin material 5 Multilayer skin material 6 Multilayer skin material 10 Polypropylene-type resin foam layer 12 Inorganic fiber sheet 14 Inorganic fiber sheet 16 Polyethylene Resin Film 18 Polyethylene Resin Film 20 Polyethylene Resin Film 22 Polyethylene Resin Film 24 Composite Fiber Sheet 26 Composite Fiber Sheet 28 Polypropylene Resin Foam Laminated Sheet 30 Interior Material Base Material 32 Interior Material Base Material

Claims (15)

  A base material for interior material in which a multilayer skin material B is laminated on one side of a polypropylene resin foam laminated sheet (A), wherein the multilayer skin material (B) is provided with air permeability by providing a through hole. A multilayer skin material in which the film (b3) is interposed between a skin material (b1) made of a knitted fabric or a nonwoven fabric and a non-sound absorbing soft urethane (b2), and the polypropylene resin foam laminated sheet ( A) is a polypropylene resin foam laminate sheet in which a reinforcing layer (a2) is laminated on both surfaces of a polypropylene resin foam layer (a1) having an open cell ratio of 55 to 98%. Substrate for use.   The base material for interior materials according to claim 1, wherein the polypropylene resin foam layer (a1) in the polypropylene resin foam laminate sheet (A) has an expansion ratio of 10 to 20 times. The compression gradient at 23 ° C of the polypropylene resin foam layer (a1) in the polypropylene resin foam laminate sheet (A) is 1000 to 30000 g / cm ² / cm ² , The base material for interior materials according to 2.   The tensile elastic gradient at 23 ° C of the reinforcing layer (a2) in the polypropylene resin foam laminated sheet (A) is 100 to 500 MPa · mm, according to any one of claims 1 to 3. The base material for interior materials as described.   The interior material according to any one of claims 1 to 4, wherein the reinforcing layer (a2) in the polypropylene resin foam laminated sheet (A) is a composite sheet comprising an inorganic fiber sheet and a thermoplastic resin film. Substrate for use.   The interior material according to any one of claims 1 to 5, wherein the reinforcing layer (a2) in the polypropylene resin foam laminated sheet (A) is a composite sheet comprising an inorganic fiber sheet and a polyethylene resin film. Substrate for use.   In the polypropylene resin foam laminated sheet (A), the composite sheet comprising the inorganic fiber sheet and the polyethylene resin film as the reinforcing layer (a2) has a structure in which the inorganic fiber sheet is sandwiched between a plurality of polyethylene resin films. The base material for interior materials according to claim 6, wherein   The interior according to any one of claims 6 and 7, wherein the resin constituting the polyethylene resin film in the polypropylene resin foam laminated sheet (A) is a linear low density polyethylene resin. Base material for materials. The non-absorbing soft urethane (b2) in the multilayer skin material (B) has a ventilation resistance of 100 N · s · m ⁻³ or less and a density of 0.03 g / cm ³ or less. The interior material base material according to any one of claims 1 to 8.   The base material for interior materials according to any one of claims 1 to 9, wherein the thickness of the non-sound absorbing soft urethane (b2) in the multilayer skin material (B) is 2 mm or more.   The opening ratio of the film (b3) provided with a through hole and having air permeability in the multilayer skin material (B) is 0.9 to 25%, any one of claims 1 to 10, The base material for interior materials described in 1.   The average pore diameter of the film (b3) provided with a through hole in the multilayer skin material (B) and having air permeability is an equivalent circle diameter of 1.0 to 4.9 mmφ. The base material for interior materials in any one of -11. The multilayer skin material (B) has a ventilation resistance of 50 to 700 N · s · m ⁻³ , and the total ventilation of the multilayer skin material B. The base material for interior materials according to any one of claims 1 to 12, wherein the resistance is 70 to 2500 N · s · m ^-3 . The base material for interior materials according to any one of claims 1 to 13, wherein the basis weight of the multilayer skin material (B) is 290 g / m ² or less.   In the multilayer skin material (B), a film (b3) provided with air permeability by providing a through hole, a skin material (b1) made of a knitted fabric or a nonwoven fabric, and a non-sound absorbing soft urethane (b2) are adhesives. The base material for interior materials according to any one of claims 1 to 14, which is integrated through a layer and / or by heat fusion.

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