JP5887976B2 - Molded interior material sheet and manufacturing method thereof - Google Patents

Description

  The present invention relates to a laminate sheet for molded interior materials such as molded ceiling materials for vehicles, molded door trims, rear package trays, tonneau boards, floor materials, etc., which have excellent strength and moldability and can be incinerated, The present invention relates to a reinforcing sheet used for a reinforcing layer of a molded interior material sheet.

  Conventionally, a reinforcing layer such as a glass fiber layer for reinforcing the base material layer is formed on both surfaces of the base material layer made of a thermoformable rigid foam or the like, and a skin layer and a back surface are formed on both surfaces having the reinforcing layer. Molded interior materials such as molded ceiling materials for vehicles provided with layers are known. As a method for producing these molded interior materials, a reinforcing sheet or a base material layer coated with a thermoplastic resin is prepared, and the skin, the reinforcing sheet, the base material layer, the reinforcing sheet, and the back material are stacked and heated. A plate-like laminate is prepared by pressing, and when necessary, this laminate is preheated and cold-pressed with a press mold at room temperature and a thermoset on the reinforcing sheet or substrate layer There is known a hot press method in which a resin-coated material is prepared, and a skin, a reinforcing sheet, a base material layer, a reinforcing sheet, and a back material are stacked and pressure-molded with a heated press mold.

  Glass fiber used as a reinforcing material in such molded interior materials has a very excellent reinforcing effect and good stability in molding dimensions, and thus is widely used as molded interior materials for vehicles (for example, patents). Literatures 1-3). However, glass fiber is useful but has problems. That is, since a very small amount of arsenic is generated when incinerated for processing a molding terminal or a used product generated at the time of product molding, there is a problem in environmental problems.

  On the other hand, as a sheet that does not use glass fibers, Patent Document 4 proposes a sheet that reinforces automobile interior materials by heat-treating a web obtained by mixing hemp fibers and thermoplastic resin fibers. . In this case, the reinforcing layer is made of plant fiber and thermoplastic resin, so it is superior to glass fiber in that it does not cause environmental problems when incinerated at the time of disposal, but handling rigidity is insufficient when assembling into the vehicle body. In addition, there is a problem that the thermoplastic resin is manufactured from a fossil raw material that is feared to be depleted in the future.

  Patent Document 5 discloses an automobile interior material using bamboo fiber, cotton, hemp fiber, or the like as a reinforcing material, and using a biodegradable resin as a component for adhering them. Neither bending elastic modulus nor bending strength is sufficient. In addition, polybutylene succinate and polylactic acid are exemplified as biodegradable resins to be used, but these are known to have low heat resistance, and the molded interior material may be deformed at high temperatures in summer. Concerned.

Japanese Patent No. 3842425 JP 2008-308768 A JP 2010-53503 A Japanese Patent Laid-Open No. 2001-122046 JP 2007-160742 A

  By using a sheet containing fine plant fibers as a reinforcing material, the present invention is a molded interior that has high strength, is flammable, can be incinerated as waste, and has excellent moldability It aims at providing the sheet | seat for materials, especially the sheet | seat for motor vehicle interior materials.

  The present inventor has made various studies on methods for supplementing the strength of the reinforcing layer, that is, deformation resistance, while taking advantage of the advantages of the plant fiber, and as a result, highly refined fine plant fiber as a material for the reinforcing layer. The present inventors have found that the above-mentioned problems can be solved by using a composite sheet containing resin and resin, and have completed the following invention.

(1) At least one reinforcing material layer in a laminate sheet obtained by laminating a surface material and a back material with a reinforcing material layer sandwiched between the front and back surfaces of the core material sheet and bonding and integrating them is fine with an average fiber width of 20 to 1000 nm. The sheet | seat for shaping | molding interior materials which is a reinforcing material layer which has a composite material sheet | seat of 20-1000 micrometers in thickness containing 55 mass% or more of plant fibers, and resin.
(2) The sheet | seat for shaping | molding interior materials as described in (1) which has a reinforcing material layer which has the said composite material sheet on both front and back surfaces of a core material sheet.
(3) The molded interior material sheet according to (1) or (2), wherein the content of fine plant fibers having an average fiber width of 20 to 1000 nm in the composite material sheet is 75% by mass or more.
(4) The fine plant fiber having an average fiber width of 20 to 1000 nm in the composite sheet has a weighted average fiber length of 0.6 mm or less, and the viscosity of the 0.5% aqueous dispersion of the fine plant fiber. The sheet | seat for shaping | molding interior materials of any one of (1) term-(3) term which is a fine plant fiber whose is 100 mPa * s or more.
(5) The sheet | seat for shaping | molding interior materials of any one of the (1) term-(4) term whose tensile strength of the said composite material sheet is 100 Mpa or more.

(6) A method for producing a sheet for molded interior material according to any one of items (1) to (5), comprising fine plant fibers having an average fiber width of 20 to 1000 nm and a resin. A composite sheet forming step of forming a composite sheet containing the fine plant fibers by a sheet forming method using a turbid liquid, and a skin with a reinforcing material layer having the composite sheet sandwiched between the front and back surfaces of the core sheet A method for producing a sheet for molded interior material, comprising a laminate sheet forming step of laminating a material and a back material and bonding and integrating the whole.
(7) The molding according to (6), wherein the sheet forming method in the composite sheet forming step for forming the composite sheet containing the fine plant fibers is a sheet forming method selected from a papermaking method and a coating method. A method for producing a sheet for interior materials.

(8) A reinforcing material for molded interior material comprising a composite sheet having a thickness of 20 to 1000 μm and containing 55% by mass or more of fine plant fibers having an average fiber width of 20 to 1000 nm and a resin.

(9) The fine plant fiber having an average fiber width of 20 to 1000 nm, a weighted average fiber length of 0.6 mm or less, and a 0.5% aqueous dispersion having a viscosity of 100 mPa · s or more. The reinforcing material for molded interior material according to (8), which is a fiber.

  According to the present invention, a molded interior material capable of incinerating waste with high strength and flammability, particularly a molded interior material for automobiles, a molded interior material sheet excellent in moldability suitable for production thereof, and the A composite material sheet suitable for forming a reinforcing layer of a molded interior material sheet is provided.

It is the top view (a) of the press metal mold | die used for evaluation of the moldability of the shaping | molding interior material sheet of this invention in the curved surface, and the side view (b) of a pair of male-female metal mold | die.

Hereinafter, the present invention will be described in detail.
The type of plant fiber used as the raw material for the fine plant fiber in the present invention is not particularly limited, but chemical pulp fibers, refiners, grinders, etc., which are obtained by digesting conifers and hardwoods by craft method, sulfite method, soda method, polysulfide method, etc. Examples include mechanical pulp fiber pulped by mechanical force, semi-chemical pulp fiber pulped by mechanical force after pretreatment with chemicals, or waste paper pulp fiber, unbleached (before bleaching) or bleached (after bleaching), respectively. Can be used. Non-wood fibers produced from herbs include, for example, fibers obtained by pulping cotton, manila hemp, flax, straw, bamboo, pagas, kenaf and the like in the same manner as wood pulp.

  In order to obtain a molded interior material that is required to have high strength like an automobile interior material, the average fiber width of fine plant fibers needs to be 20 nm to 1000 nm. Preferably they are 50 nm to 800 nm, More preferably, they are 80 nm-500 nm. If it is less than 20 nm, it is not preferable because the drainage becomes worse when producing a composite sheet by the papermaking method, and if it exceeds 1000 nm, the cellulose fibers are insufficiently refined, so that only strength equivalent to that of ordinary paper can be obtained. The fine plant fiber in the range of the average fiber width defined in the present invention can be obtained, for example, by highly beating commercial pulp. Examples of machines used for beating include commonly used beating machines such as a beater, a conical refiner, a Jordan, a single disc refiner, and a double disc refiner.

  The fiber width of the fine plant fiber is measured by electron microscope observation as follows. An aqueous suspension of fine fibers having a concentration of 0.05 to 0.1% by mass was prepared, and the suspension was cast on a carbon membrane-coated grid subjected to a hydrophilic treatment and dried, followed by negative staining with uranyl acetate. A sample for TEM observation. When a wide fiber is included, an SEM image of the surface cast on the sample stage may be observed. Observation with an electron microscope image is performed at a magnification of 1000 times, 5000 times, 10000 times, or 50000 times depending on the width of the constituent fibers. However, the sample, observation conditions, and magnification are adjusted to satisfy the following conditions.

(1) One straight line X is drawn at an arbitrary location in the observation image, and 20 or more fibers intersect the straight line X.
(2) A straight line Y perpendicular to the straight line is drawn in the same image, and 20 or more fibers intersect the straight line Y.
The width of the fiber that intersects with the straight line X and the straight line Y is visually read from the observation image that satisfies the above conditions. In this way, at least three sets of images of the surface portion that do not overlap each other are observed, and the width of the fiber intersecting with the straight line X and the straight line Y is read for each image. Thus, at least 20 × 2 × 3 = 120 fiber widths are read. The fine fiber width of the present invention is an average value of the fiber widths read in this way.
In general, the viscosity increases as the fiber width decreases and the fiber aspect ratio increases. In the case of fine plant fibers used in the present invention, when the paper length is shorter and the fiber width is narrower, a dense paper layer is formed when paper is made, and the resulting paper sheet tends to have high tensile strength.

  The fine plant fiber used in the present invention preferably has a length weighted average fiber length of 0.60 mm or less and a 0.5% aqueous dispersion having a viscosity of 100 mPa · s or more. In the case of fine plant fibers having a length-weighted average fiber length of more than 0.60 mm and a viscosity of 0.5% aqueous dispersion of less than 100 mPa · s, only a bulky sheet can be obtained when paper is produced. Tensile strength tends to be low. When used as a reinforcing material for a molded interior material, a higher sheet tensile strength is preferable because the sheet is less likely to be torn during molding. The sheet tensile strength is preferably 100 MPa or more, and more preferably 120 MPa or more.

  Chemical additives such as fillers, sizing agents, paper strength enhancers, yield improvers, etc. necessary for the purpose and purpose can be added to the suspension containing fine plant fibers, and polymer emulsions are mixed. You may do it. In particular, the use of a polymer emulsion having a low melting point is preferable because it easily adheres to a core material such as urethane foam at the time of heat press molding in the process of producing a molded interior material. Further, when a polymer emulsion having a small particle diameter is used, a sheet having a higher strength can be formed in order to uniformly mix with fine plant fibers than when a fibrous polymer is used.

Here, the polymer emulsion is an emulsion of a natural or synthetic polymer, and is a milky white liquid dispersed in water with fine polymer particles having a particle diameter of about 0.001 to 10 μm. These polymer emulsions are usually produced by emulsion polymerization, but are sometimes called polymer latexes. Emulsion polymerization is a kind of radical polymerization and is basically a polymerization method in which a monomer and an emulsifier that are hardly soluble in a medium are mixed in an aqueous medium, and a polymerization initiator that is soluble in the medium is added. The polymer emulsion is not particularly limited, but polystyrene, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, ethylene-vinyl acetate copolymer, poly (meth) acrylic acid alkyl ester polymer, (meth) acrylic. Acid alkyl ester copolymer, poly (meth) acrylonitrile, polyester, polyurethane resin emulsion, natural rubber, styrene-butadiene copolymer, (meth) acrylonitrile-butadiene copolymer, polyisoprene, polychloroprene, styrene-butadiene -Methyl methacrylate copolymer, styrene- (meth) acrylic acid alkyl ester copolymer and the like.
Further, a polymer resin such as polyethylene, polypropylene, polyurethane, ethylene-vinyl acetate copolymer and the like may be emulsified by a post-emulsification method.

  In the present invention, in consideration of the yield and dehydration property when mixing an aqueous suspension of fine plant fibers and a polymer emulsion to form a sheet, the particle size of the polymer emulsion should be large, but if it is too large, the sheet Therefore, the range of 0.001 to 10 μm which is an appropriate size suitable for the purpose is preferable. Among these, when the surface charge is cationic, the polymer emulsion is advantageous in terms of dispersion stability and yield.

  A mixed solution containing fine plant fibers containing a polymer emulsion is prepared by adding the polymer emulsion to an aqueous suspension of fine plant fibers while stirring. As an agitation device, an agitator, a homomixer, a pipeline mixer or the like is used for uniform mixing and agitation.

  The composite sheet constituting the reinforcing layer in the molded interior sheet of the present invention preferably has a content of fine plant fibers of 55% by mass or more. 75 mass% or more is more preferable, and the range of 90-99 mass% is the most preferable. It is expected that various functions can be expressed by combining fine plant fibers and the above polymer emulsion by papermaking. However, if the proportion of fine plant fibers is less than 55% by mass, hydrogen bonding in the sheet is inhibited. As a result, sufficient strength cannot be obtained. In addition, it is not preferable from the viewpoint of environmental protection to increase the proportion of the polymer mainly using fossil raw materials.

  The fine plant fiber-containing suspension is dehydrated and then formed into a sheet through a pressing process and a drying process in the same manner as ordinary papermaking. The wet paper sheet is dried by general drying equipment such as a Yankee dryer, a cylinder dryer, a through dryer, and an oven. Further, if necessary, the surface can be smoothed by a machine calendar or a super calender and densified to improve the strength.

Moreover, the composite material sheet which comprises the reinforcement layer in the sheet | seat for molded interior materials of this invention can be produced also by the coating method using the fine plant fiber containing suspension. In this coating method, a fine plant fiber-containing suspension, which is a fine plant fiber-containing suspension, is coated on a base material and dried to peel the fine plant fiber-containing layer formed from the base material. This is a method for obtaining a paper sheet made of fibers. By using a continuous coating apparatus and a long substrate, a composite material sheet can be continuously produced as a paper sheet made of fine plant fibers.
As the base material used in the coating method, it is preferable that the wettability with respect to the suspension containing fine plant fibers is high because the shrinkage of the sheet during drying is suppressed. It is necessary to select a layer having good releasability when the layer is peeled from the base sheet.

  As the substrate, a resin plate or a metal plate having both of the above required characteristics is suitable. For example, an acrylic plate, a polyfluorinated ethylene plate, a polyethylene phthalate plate, a vinyl chloride plate, a polystyrene plate, a resin plate such as a polyvinylidene chloride plate, a metal plate such as an aluminum plate, a zinc plate, a copper plate, and an iron plate, and those metal plates A metal plate such as a surface-treated metal plate having a surface oxidized, a stainless steel plate, or a brass plate can be used.

In order to apply the raw material pulp slurry, which is a fine vegetable fiber-containing suspension, onto the base material, various coaters that can apply a predetermined amount of slurry to the base material may be used.
As the coating apparatus, for example, a roll coater, a gravure coater, a die coater, a curtain coater, a spray coater, a blade coater, a rod coater, an air doctor coater, etc. can be used, among which a die coater, a curtain coater, a spray coater, an air coater, etc. A coating method such as a doctor coater is particularly effective in forming a uniform coating layer.

For drying the coating layer, hot air drying, infrared drying, vacuum drying, or the like can be employed. A continuous composite sheet can be manufactured by applying a fine vegetable fiber suspension with a coater using a long winding plate on the substrate and drying to form a sheet containing fine plant fibers. Become. The fine plant fiber-containing sheet formed on the long substrate may be wound together with the substrate and peeled off from the substrate at the time of use, or the fine plant fiber-containing sheet is peeled off before winding the substrate, And paper sheets may be formed as separate windings.
The viscosity of the fine plant fiber suspension at the time of coating is preferably 10,000 mPa · s or less, and more preferably 100 to 5000 mPa · s.

  The film thickness of the composite material sheet containing fine plant fibers used as the reinforcing material layer of the sheet for molded interior material of the present invention is preferably 20 μm to 1000 μm, more preferably 30 to 300 μm, and most preferably 50 μm to 200 μm. . When it is used as a reinforcing material when the thickness is less than 20 μm, the cross-sectional secondary moment of the obtained laminate sheet becomes small and the rigidity becomes small, which is not preferable as a sheet for molded interior material. When used as a sheet for molded interior material, workability during molding deteriorates, which is not preferable.

  The composite material sheet containing fine plant fibers thus obtained can be used as a sheet material for forming a reinforcing layer of a molded interior material, in particular, an automotive molded interior material sheet. For example, it can be used for a reinforcing layer of a molded interior material sheet produced by press molding of molded ceiling materials for automobiles, molded door trims, rear package trays, floor materials and the like. Moreover, it is applicable not only for a motor vehicle but also for a reinforcing layer of a molded interior sheet for other vehicles.

  As a method for producing a sheet for molded interior material, a sheet in which a thermosetting adhesive is applied to a fine plant fiber-containing sheet is prepared, this is laminated on both surfaces of urethane foam, and a skin material and a back material are further arranged. Alternatively, pressure molding may be performed in a heated mold. When used as a molded ceiling material, a core material layer made of urethane foam has a thickness of 3 mm or more and 15 mm or less. In addition, a thermosetting adhesive is applied to both sides of the urethane foam (for example, spray coating), a fine vegetable fiber sheet is stacked on both sides, and a skin material or back surface material is further stacked on the heating mold. A method may be used in which the molded product is taken out from the mold after being put and pressurized to cure the adhesive.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited to these examples. Moreover, unless otherwise indicated, the part and% in an example show a mass part and mass%, respectively.

(Preparation of fine plant fiber)
Softwood bleached kraft pulp (manufactured by Oji Paper Co., Ltd., moisture 50%, Canadian standard freeness (CSF) measured according to JIS P8121 is 550 ml) is added with water to a concentration of 2% and disaggregated with a disintegrator. A pulp suspension was obtained. This pulp suspension was refined with a refiner (trade name: “KRK High Concentration Disc Refiner”, manufactured by Kumagai Riki Kogyo Co., Ltd.) and a high-pressure collision type disperser (trade name: “Ultimizer”, manufactured by Sugino Machine, Inc.) Using defibration. At this time, six types of dispersion liquids (defibration fibers A to F) having different treatment levels were prepared by changing the number of passes between the refiner and the high-pressure collision type disperser.
About the obtained defibrated fibers A to F, the length-weighted average fiber length, the B-type viscosity (rotor No. 4, rotation speed 60 rpm) at a temperature of 25 ° C. and 0.5% fine plant fiber, average cellulose fiber The width was measured.

The fiber width of the fine plant fiber was measured by electron microscope observation as follows.
An aqueous suspension of fine fibers having a concentration of 0.05 to 0.1% by mass is prepared, and the suspension is cast on a sample stage to obtain a sample for SEM observation. A high-resolution SEM (S-5000, Inc.) More than 20 (pieces) were selected from photographs taken by Hitachi Science Systems, and the average value was defined as the fiber width. The measured values are shown in Table 1.

(Preparation of fine plant fiber-containing sheet)
Composite sheet 1 (sheet 1):
After mixing 2 parts of polypropylene emulsion (trade name: “P-9018” (average particle size: 0.058 μm), manufactured by Toho Chemical Co., Ltd.) with 98 parts of defibrated fiber A, 0.2 part of cation A coagulant (trade name: “Fixage 621”, manufactured by Kurita Kogyo Co., Ltd.) was added and stirred for 1 minute. The obtained dispersion was cast on a filtration bottle having a 2.5-mesh plastic wire LL70-E (manufactured by Nippon Filcon Co., Ltd.) placed on a 40-mesh wire mesh, and filtered while sucking with an aspirator. The paper sheet in a wet paper state was dried while being pressurized to 0.2 MPa with a cylinder dryer at 70 ° C. to prepare a sheet 1 having a basis weight of 29 g / m ² and a thickness of 24 μm.

Composite sheet 2 (sheet 2):
Except for mixing 1 part of polypropylene emulsion (trade name: “P-5800” (average particle size: 0.058 μm), manufactured by Toho Chemical Industry Co., Ltd.) with 99 parts of defibrated fiber B, the same as Sheet 1 A sheet 2 having a basis weight of 290 g / m ² and a thickness of 286 μm was prepared.

Composite sheet 3 (sheet 3):
Sheet 1 except that 3 parts of ethylene-vinyl acetate emulsion (trade name: “S-401HQ” (average particle size: 0.7 μm), manufactured by Sumitomo Chemitech Co., Ltd.) was mixed with 97 parts of defibrated fiber C. Similarly, a sheet 3 having a basis weight of 85 g / m ² and a thickness of 72 μm was produced.

Composite sheet 4 (sheet 4):
Sheet 1 except that 1 part of ethylene-vinyl acetate emulsion (trade name: “S-752” (average particle size: 0.5 μm), manufactured by Sumitomo Chemitech Co., Ltd.) is mixed with 99 parts of defibrated fiber D. Similarly, a sheet 4 having a basis weight of 180 g / m ² and a thickness of 162 μm was produced.

Composite sheet 5 (sheet 5):
Sheet 1 except that 3 parts of ethylene-vinyl acetate emulsion (trade name: “S-401HQ” (average particle size: 0.7 μm), manufactured by Sumitomo Chemitech Co., Ltd.) was mixed with 97 parts of defibrated fiber E. Similarly, a sheet 5 having a basis weight of 115 g / m ² and a thickness of 105 μm was produced.

Composite sheet 6 (sheet 6):
It is the same as Sheet 1 except that 10 parts of anionic polyethylene emulsion (trade name: “E-2213” (average particle size: 0.07 μm), manufactured by Toho Chemical Industry Co., Ltd.) are mixed with 90 parts of defibrated fiber A. Thus, a sheet 6 having a basis weight of 107 g / m ² and a thickness of 105 μm was produced.

Composite sheet 7 (sheet 7):
Same as sheet 1 except that 20 parts of anionic polyethylene emulsion (trade name: “E-2213” (average particle size: 0.07 μm), manufactured by Toho Chemical Industry Co., Ltd.) are mixed with 80 parts of defibrated fiber B. Thus, a sheet 7 having a basis weight of 280 g / m ² and a thickness of 270 μm was produced.

Composite sheet 8 (sheet 8):
Except for mixing 10 parts of anionic acrylic emulsion (trade name: “VONCOAT CP-6190”, manufactured by DIC Corporation, solid content 40%, Tg: 43 ° C., particle size 100 nm) with 90 parts of defibrated fiber C In the same manner as Sheet 1, Sheet 8 having a basis weight of 170 g / m ² and a thickness of 145 μm was produced.

Composite sheet 9 (sheet 9):
Except for mixing 25 parts of anionic acrylic emulsion (trade name: “VONCOAT CP-6190”, manufactured by DIC Corporation, solid content 40%, Tg: 43 ° C., particle size 100 nm) with 75 parts of defibrated fiber E In the same manner as Sheet 1, Sheet 9 having a basis weight of 220 g / m ² and a thickness of 215 μm was produced.

Composite sheet 10 (sheet 10):
Same as Sheet 1, except that 30 parts of anionic polyethylene emulsion (trade name: “E-2213” (average particle size: 0.07 μm), manufactured by Toho Chemical Industry Co., Ltd.) are mixed with 70 parts of defibrated fiber A. Thus, a sheet 10 having a basis weight of 108 g / m ² and a thickness of 104 μm was produced.

Composite sheet 11 (sheet 11):
Sheet except that 45 parts of acrylic emulsion (trade name: “VONCOAT CP-6190”, manufactured by DIC Corporation, solid content 40%, Tg: 43 ° C., particle size 100 nm) is mixed with 55 parts of defibrated fiber A. In the same manner as in Example 1, a sheet 11 having a basis weight of 109 g / m ² and a thickness of 106 μm was produced.

Composite sheet 12 (sheet 12):
The same as Sheet 1 except that 99 parts of defibrated fiber A was mixed with 1 part of a polypropylene emulsion (trade name: “P-9018” (average particle size: 0.058 μm), manufactured by Toho Chemical Industry Co., Ltd.). A sheet 13 having a basis weight of 340 g / m ² and a thickness of 330 μm was produced.

Composite material sheet 13 (sheet 13):
Same as Sheet 1 except that 1 part of anionic polyethylene emulsion (trade name: “E-2213” (average particle size: 0.07 μm), manufactured by Toho Chemical Industry Co., Ltd.) is mixed with 99 parts of defibrated fiber F. Thus, a sheet 13 having a basis weight of 102 g / m ² and a thickness of 99 μm was produced.

Composite sheet 14 (sheet 14):
Same as sheet 1 except that 45 parts of defibrated fiber A were mixed with 55 parts of an anionic polyethylene emulsion (trade name: “E-2213” (average particle size: 0.07 μm), manufactured by Toho Chemical Co., Ltd.). Thus, a sheet 14 having a basis weight of 115 g / m ² and a thickness of 102 μm was produced.

Composite material sheet 15 (sheet 15):
Same as sheet 1, except that 60 parts of anionic polyethylene emulsion (trade name: “E-2213” (average particle size: 0.07 μm), manufactured by Toho Chemical Industry Co., Ltd.) are mixed with 40 parts of defibrated fiber A. Thus, a sheet 15 having a basis weight of 120 g / m ² and a thickness of 105 μm was produced.

Composite material sheet 16 (sheet 16):
The same as Sheet 1 except that 99 parts of defibrated fiber A was mixed with 1 part of a polypropylene emulsion (trade name: “P-9018” (average particle size: 0.058 μm), manufactured by Toho Chemical Industry Co., Ltd.). A sheet 16 having a basis weight of 18 g / m ² and a thickness of 15 μm was produced.

Composite material sheet 17 (sheet 17):
The same as Sheet 1 except that 99 parts of defibrated fiber A was mixed with 1 part of a polypropylene emulsion (trade name: “P-9018” (average particle size: 0.058 μm), manufactured by Toho Chemical Industry Co., Ltd.). A sheet 17 having a basis weight of 1150 g / m ² and a thickness of 1005 μm was produced.

Example 1 (Reference Example)
A foamed urethane sheet having a thickness of 5 mm and a mass of 170 g / m ² is used as a core material, and a polyisocyanate adhesive is applied to both sides of the sheet 1, and then the skin (inside the vehicle interior), sheet 1, foamed urethane sheet, adhesive The sheet 1 and the back material (polyester woven fabric) were superposed in this order. Next, this laminate was placed in a press mold and subjected to press molding at 130 ° C. for 1 minute to prepare a sample. Moreover, press molding was performed with a press mold in which the molding surface shown in FIG. 1 was formed into a curved surface, and the moldability of the sample was evaluated.

Example 2
A sample was prepared in the same manner as in Example 1 except that the sheet 2 was used.

Example 3
A sample was prepared in the same manner as in Example 1 except that the sheet 3 was used.

Example 4
A sample was prepared in the same manner as in Example 1 except that the sheet 4 was used.

Example 5
A sample was prepared in the same manner as in Example 1 except that the sheet 5 was used.

Example 6
A sample was prepared in the same manner as in Example 1 except that the sheet 6 was used.

Example 7
A sample was prepared in the same manner as in Example 1 except that the sheet 7 was used.

Example 8
A sample was prepared in the same manner as in Example 1 except that the sheet 8 was used.

Example 9
A sample was prepared in the same manner as in Example 1 except that the sheet 9 was used.

Example 10 (Reference Example)
A sample was prepared in the same manner as in Example 1 except that the sheet 10 was used.

Example 11 (Reference Example)
A sample was prepared in the same manner as in Example 1 except that the sheet 11 was used.

Example 12
A sample was prepared in the same manner as in Example 1 except that the sheet 12 was used.

Comparative Example 1
A sample was prepared in the same manner as in Example 1 except that the sheet 13 was used.

Comparative Example 2
A sample was prepared in the same manner as in Example 1 except that the sheet 14 was used.

Comparative Example 3
A sample was prepared in the same manner as in Example 1 except that the sheet 15 was used.

Comparative Example 4
A sample was prepared in the same manner as in Example 1 except that the sheet 16 was used.

Comparative Example 5
A sample was prepared in the same manner as in Example 1 except that the sheet 17 was used.

[Evaluation method]
(Tensile elastic modulus and tensile strength of sheet)
Measured according to JIS P 8113, and the strength per unit area was expressed in MPa.

(Maximum bending load of specimen, bending elastic gradient)
Measurement was performed according to JIS K 6911.

(Formability of sample)
When molding was performed with the press mold shown in FIGS. 1A and 1B, it was visually evaluated whether the sample skin could be molded without wrinkles. After molding, the back material was peeled off to evaluate whether the sheet was torn.
(Double-circle): It was able to shape | mold without a wrinkle and not tearing a sheet | seat.
○: Although the wrinkles slightly changed, the sheet could be formed without tearing.
Δ: The sheet was torn slightly from the wrinkles.
▲: Although the wrinkles were large, the sheet could be formed without tearing.
X: The sheet was torn because the wrinkles were large.
The above evaluation results are shown in Tables 2 and 3.

  As is clear from Tables 2 and 3, in Examples 1 to 12, samples having strong maximum bending strength and bending elastic gradient and good moldability were obtained. On the other hand, in Comparative Examples 1 and 3, the maximum bending strength was low, the sheet was torn, and the molded interior material was wrinkled. Although Comparative Examples 2 and 4 were relatively good in terms of formability, the maximum bending strength was low and the bending elastic gradient was also low. In Comparative Example 5, the maximum bending strength was high and the sheet was not torn, but the wrinkles were close.

  The sheet for molded interior material of the present invention is required to have high strength and excellent formability, and is flammable and capable of incineration treatment as waste with high strength. It is useful as an interior material. In particular, it can be applied not only to automobiles as interior materials such as molded ceiling materials, molded door trims, rear package trays, tonneau boards and floor materials, but also to molded interior materials for other vehicles.

Claims (4)

In the sheet for molded interior material, in which the reinforcing material layer is sandwiched between the front surface and the back surface of the core sheet, and the skin material and the back material are laminated and integrated .
At least one reinforcing material layer has an average fiber width of 20 to 1000 nm, a weighted average fiber length of 0.6 mm or less, and a 0.5% concentration aqueous dispersion having a viscosity of 100 mPa · s or more of 75 % by mass or more. and containing a resin, thickness 50 ～1000Myuemu, tensile strength of the reinforcing material layer of a composite sheet is more than 100 MPa, the sheet molding interior material. The sheet | seat for shaping | molding interior materials of Claim 1 which has a reinforcing material layer which has the said composite material sheet in the front and back both surfaces of a core material sheet. In the manufacturing method of the sheet for molded interior material, in which the surface material and the back material are laminated and bonded and integrated with the reinforcing material layer sandwiched between the front surface and the back surface of the core material sheet,
An aqueous suspension and a polymer emulsion containing fine plant fibers having an average fiber width of 20 to 1000 nm, a weighted average fiber length of 0.6 mm or less, and a 0.5% concentration aqueous dispersion having a viscosity of 100 Pa · s or more. , A sheet forming step of obtaining a composite sheet having a thickness of 50 to 1000 μm and a tensile strength of 100 MPa or more by a sheet forming method by mixing with fine plant fibers to be 75 mass% or more (solid content), and a core material For a molded interior material, comprising a laminate sheet forming step of laminating a skin material and a back surface material by sandwiching a reinforcing material layer having the composite sheet between the front surface and the back surface of the sheet, and bonding and integrating the whole Sheet manufacturing method . In the manufacturing method of the sheet for molded interior material, in which the surface material and the back material are laminated and bonded and integrated with the reinforcing material layer sandwiched between the front surface and the back surface of the core material sheet,
An aqueous suspension and a polymer emulsion containing fine plant fibers having an average fiber width of 20 to 1000 nm, a weighted average fiber length of 0.6 mm or less, and a 0.5% concentration aqueous dispersion having a viscosity of 100 Pa · s or more. , A sheet forming step for obtaining a composite material sheet having a thickness of 50 to 1000 μm and a tensile strength of 100 MPa or more by a sheet forming method by a coating method by mixing so that fine plant fibers are 75% by mass or more (solid content), and a core material For a molded interior material, comprising a laminate sheet forming step of laminating a skin material and a back surface material by sandwiching a reinforcing material layer having the composite sheet between the front surface and the back surface of the sheet, and bonding and integrating the whole Sheet manufacturing method .

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