JP5524592B2 - Reinforcing sheet and sheet-like structural material using the same - Google Patents

Description

  The present invention relates to a reinforcing sheet for reinforcing a sheet material by adhering to one or both sides of a sheet material such as a ceiling interior material for automobiles or a building material, and a sheet-like structural material using the same.

  In general, ceiling interior materials and building materials for automobiles are required to have heat insulation, sound absorption, strength, dimensional stability, and the like. On the other hand, in recent years, for ceiling interior materials for automobiles, in addition to such demands for heat insulation, etc., in addition to the human and resource environment such as light weight, workability in manufacturing process, reduction of industrial waste, etc. Consideration is strongly demanded.

As a conventional automotive ceiling interior material, for example, an automotive molded ceiling material has been developed in which glass chopped strand mats are bonded to both surfaces of a polyurethane foam sheet with a binder (see Japanese Patent No. 4026455). This glass chopped strand mat is formed by bonding glass chopped strands with a basis weight of 80 to 200 g / m ² .

  However, the above-mentioned conventional molded ceiling material for automobiles uses a glass chopped strand mat as a reinforcing material for the polyurethane foam sheet, and is excellent in strength, dimensional stability, heat insulation, productivity, etc. Therefore, environmental problems such as workability in the manufacturing process and reduction of industrial waste cannot be cleared. Further, in the above conventional molded ceiling material for automobiles, since a large amount of adhesive is used for bonding the glass chopped strand mat to the foamed polyurethane sheet, there is a disadvantage that workability is deteriorated due to equipment contamination. There is a tendency to inhibit the sound-absorbing property.

  Thus, there is currently no reinforcing sheet that can impart strength and is excellent in environmental suitability.

Japanese Patent No. 4026455

  The present invention has been made in view of these disadvantages, and is excellent in tensile strength with respect to a sheet material by adhering to one or both surfaces of a sheet material such as an automobile interior material or a building material via an adhesive. An object of the present invention is to provide a reinforcing sheet that imparts bending strength and is excellent in lightness, sound absorption, and environmental suitability, and a sheet-like structural material using the same.

The invention made to solve the above problems is
A reinforcing sheet that can be impregnated with adhesive on one or both sides of the sheet material,
It is obtained by papermaking a composition containing natural fibers,
A reinforcing sheet having a plurality of through holes.

  This reinforcing sheet is solidified in a state in which an adhesive is impregnated between natural fibers by adhering to one or both sides of the sheet material via an adhesive depending on the type or application of the sheet material, Tensile strength and bending strength can be imparted to. Moreover, the said reinforcement sheet | seat can implement | achieve the reduction | decrease etc. of an industrial waste, providing a tensile strength, bending strength, and lightweight property with a sufficient balance by containing a natural fiber. Furthermore, this reinforcing sheet has a plurality of through-holes, so that the weight of the reinforcing sheet can be significantly reduced, and the amount of adhesive used for bonding with the sheet material can be efficiently reduced. When the sheet material has the through-hole portion, the sound absorption can be improved.

  The surface shape of the through-hole is elliptical, the opening shape on the reinforcing sheet surface is flattened in a certain direction, and the flatness ratio is preferably 0.01 or more and 0.8 or less. Since the opening shape of the through hole in the reinforcing sheet surface is flattened in a certain direction and the flatness ratio is in the above range, the reinforcing effect such as strength can be made different between the flat direction and the substantially vertical direction. That is, anisotropy can be imparted to the reinforcing effect.

  As described above, the long diameter direction of the through hole flattened in a certain direction is preferably substantially perpendicular to the paper making direction of the natural fiber, that is, substantially the same as the paper making width direction (MD direction). Normally, when pulp-based natural fiber is made into a sheet, the paper making direction (longitudinal strength) becomes high and the strength in the width direction becomes weak. By making the major axis direction of the through hole in the reinforcing sheet substantially the same as the width direction like this means, the reinforcing effect such as tensile strength and bending strength is relatively small in the fiber direction and relatively large in the vertical direction. As a result, the isotropy of the reinforcing effect can be improved.

  The composition may further include thermoplastic synthetic fibers and / or non-thermoplastic chemical fibers. By including the thermoplastic synthetic fiber in the composition of the reinforcing sheet, the thermoplastic synthetic fiber melts and penetrates between the natural fibers during the hot pressing of the reinforcing sheet to the sheet material, and the reinforcing sheet material The tensile strength, bending strength, and dimensional stability can be imparted to the reinforcing sheet material. In addition, by including non-thermoplastic chemical fibers in the composition of the reinforcing sheet, the non-thermoplastic chemical fibers are present without being softened by heat bonding to the sheet material of the reinforcing sheet, and the fiber spacing of the reinforcing sheet is maintained. Therefore, a large amount of adhesive infiltrates into the gaps of the fibers, and as a result, it is possible to impart good strength adhesion ease to the sheet material.

The opening area ratio by the through holes is preferably 10% or more and 70% or less. Also, 1 mm or more 10mm or less the average diameter of the through hole, preferably 50/100 cm ² or more 400/100 cm ² or less as the density of arrangement. By setting the opening area ratio, average diameter, and arrangement density of these through-holes within the above ranges, a high tensile strength bending strength, reduced adhesive, and lighter weight can be well balanced against the reinforcing sheet infiltrated with the adhesive. It is possible to impart sound absorption.

The density of the reinforcing sheet is preferably 0.1 g / cm ³ or more and 0.8 g / cm ³ or less. By setting the density of the reinforcing sheet within the above range, the reinforcing sheet can be more easily impregnated with the adhesive, the adhesion to the sheet material can be further facilitated, and the tensile strength that can sufficiently withstand the bonding operation to the sheet material. In addition, the bending strength can be exhibited.

  The reinforcing sheet may have a fiber structure that can be impregnated with an adhesive in a portion excluding the through hole. By sufficiently impregnating the gap in the fiber structure of the reinforcing sheet with the adhesive, the reinforcing sheet and the sheet material can be firmly bonded and fixed. As a result, the structure material to which the reinforcing sheet is bonded has high tensile strength and bending. Strength can be imparted.

  Another invention for solving the above-mentioned problems is a sheet-like structural material comprising a sheet material and a reinforcing sheet bonded to one or both surfaces of the sheet material via an adhesive. Since this sheet-like structural material uses the reinforcing sheet of the present invention as a reinforcing material, it can exhibit high tensile strength, bending strength, and lightness as described above.

  The sheet-like structural material is suitably used as an automobile interior material. Since such a sheet-like structural material is a ceiling interior material for automobiles, it is possible to reliably and effectively exhibit heat insulation, sound absorption, strength, dimensional stability, etc. as an interior ceiling material for automobiles, and an adhesive. Can be used greatly.

  Here, the “non-thermoplastic chemical fiber” means a synthetic fiber that has characteristics similar to those of a thermoplastic resin but does not exist at a temperature equal to or lower than the thermal decomposition temperature. The “average diameter of the through holes” represents an average value of the maximum inner dimension and the minimum inner dimension among arbitrary inner dimensions of the through holes.

  As described above, the reinforcing sheet of the present invention satisfies environmental problems through reducing the amount of adhesive used while satisfying the lightness, high tensile strength, ease of processing, etc. required as a reinforcing material for the sheet material. It can respond sufficiently. In addition, since the sheet-like structural material reinforced with such a reinforcing sheet can exhibit high bending strength and the like, it can be applied to various uses such as automobile interior materials and building materials.

It is a schematic plan view which shows the reinforcing sheet which concerns on one Embodiment of this invention. It is a schematic plan view which shows the reinforcing sheet of a form different from the reinforcing sheet of FIG. It is a general | schematic sectional drawing which shows the sheet-like structure using the reinforcement sheet | seat of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

(Reinforcement sheet)
The reinforcing sheet 1 in FIG. 1 is obtained by papermaking a composition containing natural fibers, and has a plurality of through holes 2.

  The reinforcing sheet 1 is a member that adheres to a sheet material (described later) via an adhesive, and imparts tensile strength, bending strength, and the like to the sheet material. Such a reinforcing sheet 1 can be adhered to one or both sides of the sheet material according to the type and use of the sheet material.

  The reinforcing sheet 1 is obtained by papermaking a composition containing natural fibers. Natural pulp is preferably used as the natural fiber material. By including natural pulp in the composition constituting the reinforcing sheet 1, strength and light weight can be imparted to the reinforcing sheet 1 in a well-balanced manner, and a reduction in industrial waste can be achieved.

  The type of the natural pulp is not particularly limited, and examples thereof include waste paper pulp, chemical pulp, mechanical pulp, sisal hemp, manila hemp, sugar cane, cotton, silk, bamboo, and kenaf. Among them, bamboo that exhibits high tensile strength and bending strength, kenaf and manila hemp with high fiber strength are preferably used, and softwood bleached kraft pulp (NBKP) described later, which is easy to obtain and process and has relatively high paper strength, is used. It is particularly preferable to do this.

  Waste paper pulp, for example, corrugated waste paper, tea waste paper, craft envelope waste paper, magazine waste paper, newspaper waste paper, flyer waste paper, office waste paper, Kami white waste paper, Kent waste paper, structured waste paper, ground waste waste paper, etc. Examples include disaggregation / deinked waste paper pulp, deinking / bleached waste paper pulp, and the like.

  Examples of chemical pulp include hardwood bleached kraft pulp (LBKP), softwood bleached kraft pulp (NBKP), hardwood unbleached kraft pulp (LUKP), conifer unbleached kraft pulp (NUKP), hardwood semi-bleached kraft pulp (LSBKP), conifer Semi-bleached kraft pulp (NSBKP), hardwood sulfite pulp, coniferous sulfite pulp and the like.

  Examples of the mechanical pulp include stone ground pulp (SGP), pressurized stone ground pulp (PGW), refiner ground pulp (RGP), chemi-ground pulp (CGP), thermo grand pulp (TGP), ground pulp (GP), and thermo. Examples include mechanical pulp (TMP), chemisermo mechanical pulp (CTMP), refiner mechanical pulp (RMP), and the like.

  The content of the natural pulp in the composition is not particularly limited and may be 100% by mass, but the upper limit of the content of the natural pulp is preferably 95% by mass, more preferably 93% by mass, 90% by mass is particularly preferred. Moreover, as a minimum of content of natural pulp, 70 mass% is preferable, 75 mass% is more preferable, and 80 mass% is especially preferable. Thus, by setting the upper limit and the lower limit of the content of natural pulp, it is possible to reliably exhibit good tensile strength and bending strength while improving the lightness of the reinforcing sheet 1. When the content of such natural pulp exceeds 95% by mass, the natural pulp fiber is not preferable because the fiber length is shorter than that of synthetic / chemical fiber, sufficient strength cannot be obtained, and the fiber may break. Moreover, it is not preferable that the content of the natural pulp is less than 70% by mass because the cost is high and it is not economical.

  As described above, the reinforcing sheet 1 obtained by papermaking a composition containing natural pulp has a gap that can be impregnated with an adhesive. By sufficiently impregnating the gap between natural pulp constituting the reinforcing sheet 1 with an adhesive, the reinforcing sheet 1 and the sheet material can be firmly bonded and fixed. As a result, the structural material to which the reinforcing sheet 1 is bonded High strength can be imparted to (described later).

  The composition may further include thermoplastic synthetic fibers and / or non-thermoplastic chemical fibers. This thermoplastic synthetic fiber does not melt in the state before the reinforcing sheet 1 is bonded to the sheet material. However, when the reinforcing sheet 1 is bonded to the sheet material by a hot press, the thermoplastic synthetic fiber is melted by the heat and is natural fiber. It penetrates in between and improves the adhesion of the reinforcing sheet 1 to the sheet material. Moreover, since such an adhesive agent is then cooled and solidified, high tensile strength and bending strength can be imparted to the structural material to which the reinforcing sheet 1 is bonded. In addition, as a result of heat-bonding the reinforcing sheet 1 to the sheet material, it is possible to realize a reduction in the amount of adhesive used. The melting point of the thermoplastic synthetic fiber may be in the range of about 100 ° C to 140 ° C.

  The type of the thermoplastic synthetic fiber is not particularly limited. For example, polyolefin fibers such as polyethylene, polypropylene, and copolymerized polypropylene; polyester systems such as polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polyethylene naphthalate, and copolyester. Fibers: Polyamide fibers such as nylon-4, nylon-6, nylon-46, nylon-66, copolymer nylon; biodegradable fibers such as polylactic acid, polybutylene succinate, and polyethylene succinate. Among them, it is preferable to use a polyolefin fiber because it is easy to handle and imparts good strength to the reinforcing sheet.

  As an upper limit of content of the thermoplastic synthetic fiber in the said composition, 15 mass% is preferable and 10 mass% is more preferable. Moreover, as a minimum of content of a thermoplastic synthetic fiber, 2 mass% is preferable and 4 mass% is more preferable. Thus, by setting the upper limit and the lower limit of the content of the thermoplastic synthetic fiber, the thermoplastic synthetic fiber melted under heating in the paper making process efficiently penetrates between the fibers of the natural pulp, and the tensile strength of the reinforcing sheet 1 In addition, the bending strength can be effectively realized. When the content of this thermoplastic synthetic fiber exceeds 15% by mass, the blending amount of natural pulp fibers decreases, the absorbability of the adhesive in the reinforcing sheet 1 decreases, and the bending strength is insufficient when used as a sheet structural material. It is not preferable because there is a risk of doing so. Further, if the content of the thermoplastic synthetic fiber is less than 2% by mass, the adhesion effect between the natural pulp fibers of the reinforcing sheet 1 is lowered, and the reinforcing sheet 1 is easily broken, which is not preferable.

  Non-thermoplastic chemical fibers are fiber bodies that do not melt during hot pressing. This non-thermoplastic chemical fiber partially inhibits hydrogen bonding between pulp fibers of the reinforcing sheet 1 without being melted or softened by the heat when the reinforcing sheet 1 is bonded to the sheet material by hot press. As a result, the fiber spacing of the pulp is maintained, and a large amount of the adhesive is infiltrated into the gaps of the fibers. As a result, it is possible to impart a good strength to the sheet material.

  Although it does not specifically limit as a kind of the said non-thermoplastic chemical fiber, For example, regenerated cellulose fibers, such as a vinylon fiber, an acrylic fiber, an aramid fiber, a rayon fiber, etc. are mentioned. Among these, a vinylon fiber having a substantially circular cross section perpendicular to the fiber direction is preferable because it can impart high strength to the reinforcing sheet 1.

  As an upper limit of content of the non-thermoplastic chemical fiber in the said composition, 20 mass% is preferable and 15 mass% is more preferable. Moreover, as a minimum of content of a non-thermoplastic chemical fiber, 2 mass% is preferable and 8 mass% is more preferable. Thus, by setting the upper limit and the lower limit of the content of the non-thermoplastic chemical fiber, the reinforcing sheet 1 can exhibit good tensile strength and bending strength without reducing the absorbability of the adhesive. When the content of the non-thermoplastic chemical fiber exceeds 20% by mass, the blended amount of natural pulp fibers with respect to the entire reinforcing sheet 1 is reduced, and the absorbability of the adhesive with respect to the reinforcing sheet 1 is lowered, which is not preferable. Further, when the content of the non-thermoplastic chemical fiber is less than 2% by mass, the fiber length of the natural pulp fiber is shorter than that of the non-thermoplastic chemical fiber. Since there exists a tendency for intensity | strength to fall, it is not preferable. Furthermore, if the content of the non-thermoplastic chemical fiber is reduced, hydrogen bonding between the pulp fibers of the reinforcing sheet 1 cannot be sufficiently inhibited, the adhesive cannot be infiltrated into the gaps of the fibers, and the bending strength may be reduced. is there.

  The reinforcing sheet 1 has a plurality of through holes 2. As described above, the reinforcing sheet 1 having the plurality of through holes 2 can achieve a significant weight reduction and can efficiently reduce the amount of the adhesive used for bonding with the sheet material. . Specifically, the reinforcing sheet 1 has a fiber structure in which a portion excluding the through hole 2 can be impregnated with an adhesive. The shape of the through-hole 2 is exemplified by a circle in the figure, but is not particularly limited, and may be, for example, an ellipse, a quadrangle (square, rectangle), or the like. It is preferable from the viewpoint of workability. In addition, the through-hole here means what has an opening part with a diameter of 1 mm or more that penetrates from the front surface of the reinforcing sheet 1 to the back surface.

  The upper limit of the opening area ratio (measured with a Luzex image analyzer manufactured by Nireco) through the through hole 2 is preferably 70%, and more preferably 60%. Moreover, as a minimum of the opening area ratio by the through-hole 2, 10% is preferable and 50% is more preferable. Thus, by setting the upper limit and the lower limit of the opening area ratio by the through-hole 2, high bending strength and light weight can be imparted to the reinforcing sheet 1 infiltrated with the adhesive. If the upper limit of the opening area ratio due to the through-holes 2 exceeds 70%, the tensile strength is lowered and the adhesion area is lowered, so that the bending strength of the reinforcing sheet 1 impregnated with the adhesive is also significantly lowered. Moreover, it is not preferable that the lower limit of the opening area ratio by the through-hole 2 is less than 10% because the workability of the reinforcing sheet 1 infiltrated with the adhesive is extremely reduced.

The upper limit of the average diameter of the through holes 2 is preferably 10 mm, and more preferably 8 mm. Moreover, as a minimum of the average diameter of the through-hole 2, 1 mm is preferable and 6 mm is more preferable. Preferably 400/100 cm ² as the upper limit of the density of arrangement of the through-holes 2, and more preferably 350/100 cm ^2. Moreover, as a minimum of the arrangement | positioning density of the through-hole 2, 50 piece / 100cm < ² > is preferable and 250 piece / 100cm < ² > is more preferable. If the average diameter of the through-holes 2 exceeds 10 mm or the arrangement density exceeds 400/100 cm ² , the non-through-hole portions become thin and may break during thermoforming, which is not preferable. Further, if the average diameter of the through holes 2 is less than 1 mm or the arrangement density is less than 50/100 cm ² , the openings are clogged with an adhesive, and the sound absorbing property of the sheet material is hindered. Because there is a fear, it is not preferable. By setting the upper limit and lower limit of the average diameter / arrangement density of the through holes 2 in this way, the reinforcing sheet 1 infiltrated with the adhesive can exhibit high strength, light weight, and sound absorption, The amount of adhesive used can be minimized.

Preferably 0.6 g / cm ³ as the upper limit of the density of the reinforcing sheet 1, 0.5g / cm ³ is more preferable. Moreover, as a minimum of the density of the reinforcement sheet 1, 0.2 g / cm < ³ > is preferable and 0.3 g / cm < ³ > is more preferable. By setting the upper limit and the lower limit of the density of the reinforcing sheet 1 in this way, the reinforcing sheet 1 can be more easily impregnated with the adhesive and can be more easily bonded to the sheet material, and can be bonded to the sheet material. It is possible to exhibit strength that can sufficiently withstand. If the density of the reinforcing sheet 1 is less than 0.2 g / cm ³ , the tensile strength and bending strength of the reinforcing sheet 1 are remarkably lowered, which is not preferable. Further, when the density of the reinforcing sheet 1 exceeds 0.6 g / cm ³ , it becomes difficult to impregnate the reinforcing sheet 1 with an adhesive, the bending strength is lowered, and an extra adhesive that cannot be completely impregnated is formed in the through holes. It is not preferable because it exudes to the exposed portion of the sheet material, and machine stains and sound absorption are reduced. In addition, this density is a value based on JISP-8118 (test method for thickness and density).

Preferably 100 g / ^{m 2} as the upper limit of the basis weight of the reinforcing sheet 1, 90g / ^{m 2} is more preferable. Moreover, as a minimum of the basic weight of the said reinforcement sheet, 70 g / m < ² > is preferable and 80 g / m < ² > is more preferable. Thus, by setting the upper limit and the lower limit of the basis weight of the reinforcing sheet 1, the balance between lightness and strength imparted to the reinforcing sheet 1 is further improved, and the adhesive has an efficient and reliable absorbability. Can be secured. Moreover, the basic weight of the reinforcement sheet 1 can be adjusted according to a use. In addition, this basic weight is a value based on JIS-P8124 (basis weight measuring method).

  The arrangement pattern of the through holes 2 in the reinforcing sheet 1 is not particularly limited, and examples thereof include a lattice pattern, a regular triangle lattice pattern, a wave pattern, a concentric pattern, and a random pattern. Among these, a lattice pattern is preferable from the viewpoint that the through hole forming process is easy.

  The upper limit of the interval between the plurality of through holes 2 (the shortest distance between a pair of adjacent holes) is preferably 10 mm, more preferably 7 mm. Moreover, as a minimum of the space | interval of the several through-hole 2, 2 mm is preferable and 4 mm is more preferable. As described above, by setting the interval between the plurality of through holes 2 within the above range, it is possible to achieve a good balance between improving the bending strength and strength of the structural material to which the reinforcing sheet 1 is bonded and reducing the amount of adhesive used. . If the interval between the plurality of through-holes 2 is less than 2 mm, the non-through-hole portion becomes thin and may break at the time of thermoforming, which is not preferable. Further, if the interval between the plurality of through holes 2 exceeds 10 mm, the opening is clogged with an adhesive, which is not preferable because the sound absorbing property of the sheet material may be hindered.

  The reinforcing sheet 11 in FIG. 2 is obtained by papermaking a composition mainly containing natural pulp, as with the reinforcing sheet 1 in FIG. 1, and has a plurality of through holes 12. The shape of the opening in the reinforcing sheet surface of the through hole 12 is different from the through hole 2 of the reinforcing sheet 1 in FIG.

  The shape of the opening in the reinforcing sheet surface of the through hole 12 is flat in a certain direction. The planar shape of the through-hole 12 flattened in a certain direction is exemplified by an ellipse in the drawing, but is not particularly limited, and examples thereof include a rhombus, a rectangle, and those whose corners are rounded. The arrangement pattern of the through holes 12 in the reinforcing sheet 11 and the distance between the through holes 12 are the same as those of the through holes 2 described above.

About the flatness of the through-hole 12, as an upper limit in the case of using the reinforcement sheet | seat 11 for the ceiling interior material for motor vehicles, 0.7 is preferable and 0.6 is more preferable. Moreover, as a minimum of this flatness rate, 0.3 is preferable and 0.4 is more preferable. Thus, by setting the upper limit and the lower limit of the flatness ratio of the through hole 12, the reinforcing effect such as strength in the reinforcing sheet 11 impregnated with the adhesive is made different between the flat direction of the through hole 12 and the substantially vertical direction thereof. be able to. That is, anisotropy can be imparted to the reinforcing effect of the reinforcing sheet 11 impregnated with the adhesive. If the flatness ratio of the through-hole 12 exceeds 0.7, the strength in the direction perpendicular to the fiber direction is lowered, and if it is less than 0.3, there is a risk of breakage during thermoforming. The flatness f is calculated by the following formula (1) where r _{1 is} the major axis of the elliptical shape of the through-hole 12 and r ₂ is the minor axis: f = 1− (r ₂ / r ₁ ). (1)

  The major axis direction X of the through hole 12 is substantially perpendicular to the papermaking direction Y of natural pulp. As described above, the reinforcing sheet 11 is obtained by papermaking a composition containing natural pulp. Normally, when natural pulp is made into a sheet, the fiber direction (average direction) of the natural pulp is the paper making direction, and the resulting paper material is strong against the external force in the fiber direction, and the external force in the direction substantially perpendicular to it. become weak. Like this means, by making the major axis direction of the through-hole 12 in the reinforcing sheet 11 substantially the same as the paper width direction (MD direction), the tensile strength is relatively small in the fiber direction and relatively large in the vertical direction. Further, a reinforcing effect such as bending strength can be imparted, and as a result, the isotropy of the reinforcing effect can be improved.

  The major axis direction X of the through hole 12 may be substantially parallel to the fiber direction Y of the natural fiber. In this case, it is relatively large in the fiber direction and can exert a reinforcing effect.

  About the said reinforcing sheet 1 and the reinforcing sheet 11, it is preferable that the tensile strength in the state of the base paper before impregnating the below-mentioned adhesive agent is 20N or more and 30N or less. When the tensile strength of the reinforcing sheet 1 and the reinforcing sheet 11 in the base paper is in the above range, workability can be sufficiently realized while exhibiting good strength. If the tensile strength is less than 20 N, the reinforcing sheet 1 and the reinforcing sheet 11 tend to break easily, which is not preferable. Moreover, when this tensile strength exceeds 30 N, since workability | operativity may fall when sticking the reinforcement sheet 1 or the reinforcement sheet 11 to a urethane sheet, it is unpreferable.

(Reinforcing sheet manufacturing method)
As a manufacturing method of the reinforcing sheet 1 and the reinforcing sheet 11, a method generally used for papermaking can be used. Specifically, it can be manufactured by making a paper slurry of natural pulp as a main raw material through a wire part, a press part, a dryer part, and a reel part, and winding it. In such a dryer part, heat treatment is performed at about 110 degrees, and the above-mentioned thermoplastic synthetic fiber melts. Further, the calendar processing method of the reinforcing sheet 1 and the reinforcing sheet 11 is not particularly limited, and a machine calendar, a super calendar, a gloss calendar, a mat calendar, a brush calendar, a soft calendar, etc. that are set on machine can be used. it can. In addition, the reinforcing sheet 1 and the reinforcing sheet 11 can be made into a multi-layer paper by this manufacturing method. By making the reinforcing sheet 1 and the reinforcing sheet 11 into a multi-layer paper, there is an effect of increasing the mechanical strength.

  In addition to the natural pulp, the thermoplastic synthetic fiber, and the non-thermoplastic chemical fiber, an arbitrary component can be appropriately used for the raw material slurry as long as the object effects of the present invention are not impaired. As this optional component, for example, light calcium carbonate, heavy calcium carbonate, magnesium carbonate, barium carbonate, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, zinc hydroxide, clay, calcined kaolin, deramikaolin, titanium dioxide, oxidation Fillers such as zinc, silicon oxide, amorphous silica, urea-holimarin resin, polystyrene resin, phenol resin, fine hollow particles; alkyl ketene dimer sizing agent, alkenyl succinic anhydride sizing agent, neutral rosin sizing agent, etc. Sizing agent; polyacrylamide polymer, polyvinyl alcohol polymer, cationized starch, urea / formalin resin, melamine / formalin resin and other paper strength enhancer; acrylamide / aminomethylacrylamide copolymer salt, cationized starch , Polyethylene immi Yield improver such as polyethylene oxide, acrylamide / sodium acrylate copolymer; paper powder fall-off preventing agent; sulfuric acid band; wet paper strength agent; paper thickness improver; bulking agent, cationizing agent; The kind and blending amount thereof can be appropriately adjusted and added.

  About the opening means of the through-hole of the reinforcement sheet 1 and the reinforcement sheet 11, it can open using a pinch cutter, a rotary die cutter, a heat seal cutter, an ultrasonic cutter, a water jet cutter etc., for example.

(Sheet-like structural material)
3 includes a sheet material 13 and a pair of reinforcing sheets 1 laminated on both surfaces of the sheet material 13 via an adhesive 14.

  The type of sheet material 13 is not particularly limited. For example, polyurethane sheet, ABS sheet, polyamide sheet, polycarbonate sheet, polyethylene sheet, polypropylene sheet, polymethyl methacrylate sheet, polystyrene sheet, polytetrafluoroethylene sheet, polyvinyl butyral sheet, A polyvinyl chloride sheet, an acetal sheet, etc. are mentioned. In this way, the reinforcing sheet 1 can be used for various types of sheet material 13, and good bending strength can be imparted in any type.

  Although it does not specifically limit as a kind of adhesive agent 14, For example, Polyolefin type, such as polyethylene; Vinyl acetate copolymer system, such as ethylene-vinyl acetate copolymer; Acrylic acid copolymer, such as ethylene-ethyl acrylate and ethylene-isobutyl acrylate System: Polyamides such as nylon-6, nylon-66, nylon-10, nylon-12, N-methoxymethylated nylon; polyesters such as terephthalic acid; polyvinyl butyral; polyvinyl acetates; acetate, methylcellulose, Cellulose derivative systems such as acetate butyrate; Polymethacrylate systems such as polymethyl methacrylate; Polyvinyl ether systems such as polyvinyl methyl ether; Polyurethane systems; Polycarbonate systems; Styrene-ethylene-butyl Len - styrene block copolymer such as styrene; styrene-butadiene, isoprene, synthetic rubber or the like, such as butyl rubber. Among these adhesives, polyvinylacetate, polyamide, and polyester adhesives that have a low environmental burden and are thermoplastic are preferable. In addition, this adhesive agent can be used individually by 1 type or in mixture of 2 or more types.

  The sheet-like structural material 21 can exhibit high bending strength by the reinforcing sheet 1 bonded to the sheet material 13. Further, as will be described later, the sheet-like structural material 21 is used to adhere the reinforcing sheet 1 to the sheet material 13 using an adhesive 14, and the thermoplastic synthetic fiber contained in the reinforcing sheet 1 is heated. Therefore, the amount of adhesive used can be effectively reduced. In particular, when the sheet material 13 is a soundproof material, for example, the soundproof material is exposed without being covered by the reinforcing sheet 1 in the through hole 2 portion of the reinforcing sheet 1, and exhibits high sound absorption in the through hole 2 portion. For this reason, the sheet-like structural member 21 can exhibit excellent soundproofing properties.

  Moreover, the sheet-like structural material 21 sticks the reinforcement sheet 1 on both surfaces of the sheet material 13 as shown in FIG. 3, and the bending strength of the sheet-like structural material 21 is 14.3 N or more and 30 N or less. There should be. Thus, the sheet-like structural material 21 exhibits sufficient strength and durability by setting the bending strength of the sheet-like structural material 21 in which the reinforcing sheet 1 is adhered to both surfaces of the sheet material 13 within the above range. Can do. If the bending strength is less than 14.3 N, the sheet-like structural material 21 is liable to be broken by bending, which is not preferable. Moreover, when this bending strength exceeds 30 N, since it may become difficult to implement | achieve the shaping | molding ease of the sheet-like structure material 21, it is unpreferable.

(Method for producing sheet-like structural material)
As a method of manufacturing the sheet-like structural material 21 by bonding the reinforcing sheet 1 to the sheet material 13, for example, a method of bonding the reinforcing sheet 1 impregnated with the adhesive 14 to the sheet material 13 using a hot roll or the like. A binder lamination method in which the reinforcing sheet 1 is bonded to the sheet material 13 coated with the adhesive 14 using a hot roll, etc., and the adhesive 14 formed in a film shape is sandwiched between the reinforcing sheet 1 and the sheet material 13. In addition, a heat lamination method in which bonding is performed using a hot roll or the like, a method in which the reinforcing sheet 1 is temporarily fixed to the sheet material 13 via an adhesive 14, and molding and adhesion are performed simultaneously at the time of heat forming, and the like. In particular, in order to effectively impart strength and the like to the sheet-like structural material 21 to which the reinforcing sheet 1 is bonded, the reinforcing sheet 1 impregnated with the adhesive 14 is bonded to the sheet material 13 using a hot roll or the like. The method is particularly preferred.

  Examples of the method for impregnating the reinforcing sheet 1 with the adhesive 14 include dipping, spraying, kiss roll, applicator, knife coater, reverse roll coater, gravure coater, flow coater, rod coater, brush coating, and the like. Further, for the reinforcing sheet 1 impregnated with the adhesive 14, the amount of the adhesive 14 applied to the sheet material 13 by squeezing an excessive amount of the adhesive 14 using, for example, a mangle, a coating knife or the like ( (Adhesion amount) can be adjusted.

  About the said heating temperature, it can adjust arbitrarily according to the kind and application of the sheet | seat material 13. FIG. For example, when the sheet material 13 is foamable polyurethane, the heating temperature is preferably adjusted to 130 ° C. or higher. When this heating temperature is adjusted to 130 ° C. or higher, the foamable polyurethane stretches softly during heating, and the reinforcing sheet 1 also stretches following the foamable polyurethane and is set after cooling, so from the viewpoint of dimensional stability. Particularly preferred.

  In addition, the reinforcing sheet of this invention and a sheet-like structural material using the same are not limited to the said embodiment. For example, the sheet-like structural material of the present invention can be suitably used as an automobile interior material. Such automotive interior materials can reliably and effectively exhibit heat insulation, sound absorption, tensile strength and bending strength, and in recent years lightness, workability in the manufacturing process, industrial waste reduction, etc. Can fully meet the considerations and requirements of the human and resource environment. Moreover, it can use suitably especially as a reinforcement sheet | seat of a building material by making the flatness of a through-hole into 0.01, for example.

  EXAMPLES Hereinafter, although this invention is explained in full detail based on an Example, this invention is not interpreted limitedly based on description of this Example.

[Examples 1 to 33]
(Manufacture of reinforcing sheets)
As natural fiber materials constituting the reinforcing sheet, in Examples 1 to 33, NBKP which is natural pulp, polyolefin fiber which is a thermoplastic synthetic fiber (“SWP-E400” of Mitsui Chemicals), non-thermoplastic chemical fiber A vinylon (“VPB303” manufactured by Kuraray Co., Ltd.) was adjusted according to the content shown in Table 1 below to obtain a raw material slurry. In addition, this raw material slurry separately contained a sulfuric acid band, a wet paper strength agent, and polyethylene oxide as optional components.

  Subsequently, the raw material slurry was passed through a wire part, a press part, a dryer part, and a calendar part to obtain a sheet body. The drying temperature in this dryer part was adjusted to 110 ° C. Paper was made using a gap former for the wire part, a straight-through type without an open draw for the press part, and a single deck dryer for the dryer part. In the calendar part, a flattening process was performed using a multi-nip calendar. The density and basis weight were changed as shown in Table 1 by adjusting the paper making process and the flattening process.

  A substantially circular through hole was formed on the sheet body that had been subjected to the above-described planarization treatment using a die cutter. By adjusting the number and shape of the through holes, the opening area ratio and the flatness ratio were changed as shown in Table 1.

(Manufacture of sheet-like structural materials)
The reinforcing sheet obtained by the manufacturing process described above was impregnated with a polyvinyl acetate adhesive. Next, the reinforcing sheet impregnated with the adhesive was adhered to both surfaces of the foamable polyurethane sheet using a hot roll to produce a sheet-like structural material.

[Example 34]
It is the same as Examples 1-33 except that the thermoplastic synthetic fiber is polyester ("Melty" from Unitika) and the raw material slurry is adjusted based on the blending amount shown in Table 1.

[Example 35]
The same as in Examples 1 to 33 except that the non-thermoplastic chemical fiber was acrylic (Toyobo's “Bipal”) and the raw slurry was adjusted based on the blending amount in Table 1.

[Example 36]
It is the same as that of Examples 1-33 except having used natural fiber as the bamboo and adjusting the raw material slurry based on the blending amount shown in Table 1.

[Example 37]
It is the same as those in Examples 1 to 33 except that natural fiber is kenaf and the raw slurry is adjusted based on the blending amount shown in Table 1.

[Comparative example]
A glass chopped strand mat (filament diameter: 11 μm, strand count: 20 tex, convergence number: 80, strand length: 50 mm, mat basis weight: 120 g / m ² ) is heated on both sides of the foamable polyurethane sheet via an adhesive. The sheet-like structural material of the comparative example was manufactured by bonding using a roll.

(Measurement of tensile strength)
In the examples, the tensile strength of the reinforcing sheet in the state of the base paper before impregnating the adhesive was measured. Moreover, in the comparative example, the tensile strength in the state of the glass chopped strand mat before impregnating with an adhesive agent was measured. This tensile strength (N) is a value measured when the width of the test sample is 30 mm. In addition, by dividing the measured value by the sample width (30 mm), it can be converted into a unit (kN / m) described in JIS-P8113 (paper and paperboard—a test method for tensile properties). In addition, the flow direction of the tensile strength in the examples was the papermaking direction.

(Measurement of bending strength)
The bending strength (maximum load) is 50 mm / min from the upper surface using a tensile tester by taking five 50 × 150 mm test pieces from the lengthwise direction of the original fabric under constant humidity conditions of a temperature of 23 ° C. and a humidity of 50%. A load deflection was applied in a downward direction at a speed, and a deflection curve of the load was plotted to obtain the maximum load (N) required for breaking.

(Evaluation)
As shown in Table 1, Examples 1 to 37 showed a tendency to show the same tensile strength and bending strength as the comparative examples.

As described above, the reinforcing sheet of the present invention is paper-made using a composition containing natural fibers as a raw material, and is excellent in material procurement and processing, improving workability in the manufacturing process, reducing costs, Industrial waste reduction can be realized and it can be used widely and suitably.

Claims (7)

A reinforcing sheet that can be impregnated on one or both sides with an adhesive for adhering to the sheet material,
It is obtained by papermaking a composition containing natural fibers,
Have a plurality of through holes,
The reinforcing sheet is characterized in that the surface shape of the through hole is elliptical, the shape of the opening in the reinforcing sheet surface is flattened in a certain direction, and the flatness ratio is 0.01 or more and 0.8 or less . The reinforcing sheet according to claim 1 , wherein a major axis direction of the through hole is substantially perpendicular to a paper making direction of the natural fiber. The reinforcing sheet according to claim 1 or 2 , wherein the composition further comprises a thermoplastic synthetic fiber and / or a non-thermoplastic chemical fiber. The reinforcing sheet according to any one of claims 1 to 3 , wherein an opening area ratio by the through holes is 10% or more and 70% or less. The average diameter of the through holes is 1 mm or more and 10 mm or less,
Reinforcing sheet according to any one of claims 1 to 4 arrangement density of the through hole is 50/100 cm ² or more 400/100 cm ² or less. The reinforcing sheet according to any one of claims 1 to 5 , wherein the density is 0.1 g / cm ³ or more and 0.8 g / cm ³ or less. Sheet material,
A sheet-like structural material comprising: the reinforcing sheet according to any one of claims 1 to 6 , which is bonded to one or both surfaces of the sheet material via an adhesive.

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