JP5760230B2 - Cushioning sheet, sound absorbing material and filter, and method for producing the cushioning sheet - Google Patents

Description

  The present invention relates to a cushioning sheet used as a cushioning material for automobile seats, a cushioning material for floors, a sound absorbing material or a filter, and a method for producing the cushioning sheet, for example.

Conventionally, as a cushioning sheet used as a cushioning material for automobile seats or a cushioning material for floors, polyester-based short fibers, which are normal fibers, and low-melting-point fibers or core-sheath fibers are used. There are some which consist of the nonwoven fabric which bound the fiber with the melt of the core-sheath type fiber (refer patent documents 1-3). These cushioning sheets pay attention to the density in order to obtain an appropriate cushioning property, and the density of the nonwoven fabric is set to a predetermined value.
Furthermore, a cushioning sheet has been proposed in which a thermoplastic resin sheet is laminated on a highly elastic nonwoven fabric having a predetermined density, thereby providing sound absorption and sound insulation in addition to cushioning (see Patent Document 4). .
In addition to the cushioning sheet as described above, the binder resin containing the flame retardant is discontinuously adhered to at least one surface of the nonwoven fabric having a predetermined thickness and basis weight so as to exhibit suitable sound absorbing properties. A non-woven fabric sheet for sound absorbing material has been proposed (see Patent Document 5).

Japanese Patent Laid-Open No. 7-324268 JP-A-8-170259 JP-A-11-59251 JP-A-2005-14718 Japanese Patent Laid-Open No. 11-350363

However, the cushion sheet made of the above-mentioned conventional nonwoven fabric has a good cushioning property when used as a cushioning material because a gap is formed between the fibers bonded to each other by a melt of low melting point fibers. When used as a filter, it exhibits a smooth filter function. There is a problem that there is no sag, good cushioning properties cannot be maintained, and a smooth filter function cannot be maintained.
On the other hand, when the nonwoven fabric is impregnated with a binder resin like the conventional nonwoven fabric sheet for sound-absorbing material, the synthetic resin contained in the binder resin bonds the fibers to each other. The cushioning property is inhibited by the hardness due to the synthetic resin, and the filter property (breathability) is also inhibited because the synthetic resin fills the gaps between the fibers.
The present invention has been made by paying attention to such problems existing in the prior art, and an object of the present invention is to provide a cushioning sheet having good cushioning properties without sagging. The cushioning sheet is useful as a sound absorbing material and a filter. In this invention, the manufacturing method of the said cushioning sheet is provided further.

In order to achieve the above object, the invention of the cushioning sheet according to claim 1 is a thermoplastic resin having a melting point of 180 ° C. or less with respect to 100 parts by mass of a normal fiber which is a thermoplastic fiber having a melting point of 200 ° C. or more. Using mixed fibers in which low-melting fibers of fibers are mixed at a ratio of 10 to 65 parts by mass, the fibers are bonded to each other by a heated melt of low-melting fibers contained in the mixed fibers, and the thickness is 10 to A synthetic resin binder is applied to one or both sides of a fiber sheet which is set to 50 mm and the ventilation resistance is adjusted to 0.01 to 0.1 kPa · s / m by an air spray method. Set to m ² (Dry) and apply so that the thickness of the resin adhesion layer is within the range of 25% of the thickness of the fiber sheet from the upper or lower surface of the fiber sheet. 20-100 / M 2 by setting the thickness of the resin adhesion layer ^(Dry) is applied in the range of up to 50% of the thickness of said fiber sheet, the particle size of the resin in the resin adhesion layer is 0.05 to 1 and gist that by adhering so that the particulate .5mm.
The gist of the invention of claim 2 is that in the invention of the cushioning sheet of claim 1, the synthetic resin of the synthetic resin binder is a thermosetting resin and / or a pseudo thermoplastic resin.
The invention according to claim 3 is the invention of the cushioning sheet according to claim 1 or 2 , wherein the synthetic resin of the synthetic resin binder comprises a thermosetting resin and / or a pseudo thermoplastic resin, and a glass transition. The point is that it is a mixture with a thermoplastic resin having a point of 20 ° C. or higher.
The invention according to claim 4 is the invention of the cushioning sheet according to any one of claims 1 to 3 , wherein the normal fiber has a fineness of 1.0 dtex or more and a fiber length of 20 to 100 m. It is a summary that it is a thermoplastic fiber of m .
The invention according to claim 5 is the invention of the cushioning sheet according to any one of claims 1 to 4 , wherein the low melting point fiber has a fineness of 0.1 dtex or more and a fiber length of 20 to 20. The gist is that it is a thermoplastic fiber of 100 mm .
The invention of the sound absorbing material according to claim 6 is characterized in that the beating degree is 4 of JIS P 8121-1995 on one side or both sides of the cushioning sheet according to any one of claims 1 to 5 . Laminated with a fiber sheet on one or both sides of a paper sheet containing 90% by mass or more of a porous pulp fiber with a Canadian standard freeness specified by Canadian Standard Freeness in the range of 350 to 650 ml (CSF). The gist of the present invention is to laminate a sound-absorbing sheet having a ventilation resistance set in a range of 0.2 to 3.0 kPa · s / m.
The gist of the invention of the filter according to claim 7 is that it comprises the cushioning sheet according to any one of claims 1 to 5 .
Invention of the manufacturing method of the cushioning sheet of Claim 8 presses the web by which the low melting point fiber is normally mixed with the ratio of 10-65 mass parts with respect to 100 mass parts with a heating roll, A fiber made of a non-woven fabric having a thickness of 10 to 50 mm and a ventilation resistance of 0.01 to 0.1 kPa · s / m by melting the low melting point fiber and binding the normal fiber constituting the web. Spray the synthetic resin binder onto the fiber sheet by an air spray method, and attach the synthetic resin of the synthetic resin binder to the fiber sheet so that the particle size is 0.05 to 1.5 mm. Is the gist.
The invention according to claim 9 is the invention of the method for producing a cushioning sheet according to claim 8 , wherein the synthetic resin binder adheres in a range of from 25% to 25% of the thickness of the fiber sheet. And

[Action]
In the fiber sheet having a ventilation resistance of 0.01 to 0.1 kPa · s / m, an appropriate gap is formed between the fibers. Therefore, when the synthetic resin binder is sprayed, the synthetic resin binder is A predetermined depth can be reached from the surface of the fiber sheet. In a fiber sheet having a ventilation resistance of less than 0.01 kPa · s / m, the synthetic resin binder is impregnated throughout the fiber sheet, and good cushioning properties and filter properties cannot be obtained.
Since the synthetic resin of the synthetic resin binder has a particle size of 0.05 to 1.5 mm and is dispersed and adhered in the fiber sheet, the cushioning property and filter property of the fiber sheet are not inhibited, and the fiber The fibers in the sheet are firmly bound together to prevent sag.
To allowed to adhere dispersed within the fiber sheet with a grain size of the synthetic resin thus synthesized resin binder 0.05 to 1.5 mm, that apply the spray method according to an air spray system.
Furthermore, in order to give the fiber sheet a cushioning property without sagging, the synthetic resin binder is not only sprayed on the fiber sheet by an air spray method, but the fiber sheet is generally low with respect to 100 parts by mass of the fiber. the melting point fibers are mixed in a ratio of 10 to 65 parts by weight, and pressed by a heating roll, to use a nonwoven fabric bond the fibers constituting the fibrous sheet by a melt of the low-melting fibers. Since the nonwoven fabric manufactured by such a thermal bond method tends to have a uniform surface state, when the synthetic resin binder is sprayed by an air spray method, the synthetic resin of the synthetic resin binder is granular and uniform in the fiber sheet. To disperse.
Furthermore, the synthetic resin used for the synthetic resin binder is a thermosetting resin and / or a pseudo-thermoplastic resin, which has good heat resistance and does not have a bad feeling even when exposed to high temperatures (160 to 200 ° C.). It becomes the fiber sheet which has property.
The pseudo thermoplastic resin refers to a synthetic resin that behaves as a thermosetting resin at room temperature but exhibits plasticity when heated.
Furthermore, when a thermoplastic resin having a glass transition point of 20 ° C. or higher is added in addition to the thermosetting resin and / or pseudo thermoplastic resin, the elasticity is improved and the temperature is increased from a low temperature (about 15 ° C.). A fiber sheet with little shrinkage can be obtained even at high temperatures (about 200 ° C.).
Usually, in the above fiber sheet, a thermoplastic fiber having a fineness of 1.0 dtex or more, a fiber length of 20 to 100 mm, and a melting point of 200 ° C. or more is used as a normal fiber. A thermoplastic fiber having a length of 1 dtex or more, a fiber length of 20 to 100 mm, and a melting point of 180 ° C. or less is used.
The cushioning sheet of the present invention is also used as a sound absorbing material in addition to being used as a cushion material for a seat or a floor. In this case, the beating degree is JIS P 8121-1995 4. It is a laminated sheet in which a fiber sheet is laminated as a surface layer material on one or both sides of a paper sheet made of porous pulp fibers with a Canadian standard freeness specified by Canadian Standard Freeness in the range of 350 to 650 ml (CSF). Thus, a sound-absorbing material having sound-absorbing performance obtained by laminating a sound-absorbing sheet having a ventilation resistance in the range of 0.2 to 3.0 kPa · s / m on the cushioning sheet is obtained.
Furthermore, the cushioning sheet of the present invention is used as a filter having a low pressure loss, excellent dust collection, and excellent heat resistance. Such a filter is used for high-frequency air (160 to 200 ° C.) used for hot air drying. Useful as an air filter.

〔effect〕
ADVANTAGE OF THE INVENTION According to this invention, the cushioning sheet | seat which has favorable cushioning properties without a sag can be provided. Furthermore, the cushioning sheet can be provided as a useful sound absorbing material and filter.

Sectional drawing which shows the cushioning sheet | seat of embodiment. Sectional drawing which shows the sound-absorbing material of embodiment. Schematic explaining the measuring method of ventilation resistance.

Hereinafter, an embodiment embodying the present invention will be described.
[Cushioning sheet]
As shown in FIG. 1, the cushioning sheet 10 of the present embodiment includes a fiber sheet 11 and a resin adhesion layer 12 provided on a surface layer portion of the fiber sheet 11.
The said fiber sheet 11 consists of a nonwoven fabric using a mixed fiber, and is comprised by using the fiber 14 contained in this mixed fiber as a core material.
The resin adhesion layer 12 applies a synthetic resin binder to both the upper surface and the lower surface of the fiber sheet 11, and a synthetic resin 13 (hereinafter abbreviated as “resin 13”) of the synthetic resin binder is applied to the fibers 14. It is provided by adhering. In the resin adhesion layer 12, the resin 13 becomes spherical and adheres to the surface of the fibers 14 constituting the fiber sheet 11. Further, the resin 13 of the resin adhesion layer 12 is different from a normal one in which a fiber sheet is impregnated with a synthetic resin binder, for example, and does not soak into the entire fiber sheet 11 and within a predetermined range of the thickness of the fiber sheet 11. It adheres to the surface of the fiber 14.
In the cushioning sheet 10 of the present embodiment, the resin adhesion layer 12 is provided on both the upper surface and the lower surface of the fiber sheet 11. However, the present invention is not limited thereto, and only the upper surface or the lower surface of the fiber sheet 11 is used. Thus, it may be provided only on one side, that is, the resin adhesion layer 12 is provided on one side or both sides of the fiber sheet 11.
Hereinafter, each material of the cushioning sheet 10 will be described in detail.

[Mixed fiber]
As described above, mixed fibers are used as the material for the fiber sheet 11.
The mixed fibers are obtained by mixing normal fibers that are fibers 14 that serve as the core material of the fiber sheet 11 and low melting point fibers that bind the fibers of the normal fibers. And when the fiber 14 which consists of this normal fiber exhibits the elasticity and rigidity, the cushioning sheet | seat 10 exhibits cushioning properties, such as a strain and a beam.

(Normal fiber)
The normal textiles, for example polyester fibers, polyethylene fibers, polypropylene fibers, polyamide fibers, acrylic fibers, polyurethane fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, a thermoplastic fiber such as acetate fibers 200 ° C. above the melting point fiber der of Ru. Among these, polyester fibers such as polyethylene terephthalate (PET) fibers are preferable as the fibers 14 that become the core material of the fiber sheet 11 because they are excellent in heat resistance, strength, and dyeability.
The above normal fibers such as carbon fibers, glass fibers, ceramic fibers, inorganic fibers may be used in combination, such as asbestos fibers. Among these, carbon fibers are preferable as the fibers 14 that serve as the core material of the fiber sheet 11 because they are excellent in wear resistance and heat resistance and can impart flame retardancy.
More the normal fiber, biodegradable fiber made of starch extracted from plants such as corn and sugar cane, pulp, cotton, palm fiber, hemp fiber, bamboo fiber, natural fibers such as kenaf fibers or synthetic fibers or inorganic fibers, Recycled fibers obtained by defibrating scraps of fiber products using fibers such as natural fibers or the like may be used in combination .
As the normal fiber, one or more selected from those listed above are used . Further , at least one kind of thermoplastic fiber and at least one kind of inorganic fiber are mixed, or at least one kind of thermoplastic fiber and at least one kind of inorganic fiber, and at least one of biodegradable fiber, natural fiber and regenerated fiber. You may mix and use a seed.
Thermoplastic fibers for use in the above SL through normal fiber fineness of more than 1.0 dtex, fiber length 20 to 100 mm, preferably has a melting point of 200 ° C. or higher. When the fineness is less than 1.0 dtex or the fiber length is less than 20 mm, sufficient elasticity and rigidity cannot be exhibited as a core material of the fiber sheet 11, and good cushioning properties may not be obtained. . When the fiber length exceeds 100 mm, it becomes difficult for the fibers to be entangled with each other, and the fiber sheet 11 having a good texture may not be obtained. When the melting point is less than 200 ° C., even when the fibers are heated to bind the fibers, even the normal fibers may be melted.

(Low melting point fiber)
Examples of the low melting point fiber include polyolefin fibers such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, and ethylene-ethyl acrylate copolymer having a melting point of 180 ° C. or less, polyvinyl chloride fibers, polyurethane fibers, polyester fibers, and polyesters. Examples thereof include thermoplastic fibers such as copolymer fibers, polyamide fibers, and polyamide copolymer fibers. These low melting point fibers are used alone or in combination of two or more.
Further, as the low melting point fiber, for example, the core-sheath type fiber having the thermoplastic fiber mentioned as the normal fiber as a core part and the low melting point thermoplastic resin having a melting point of 100 to 180 ° C. which is a material resin of the low melting point fiber as a sheath. May be used. When the core-sheath fiber is used, the rigidity and heat resistance of the obtained fiber sheet 11 are not easily lowered.
The fineness of the low melting point fiber is preferably 0.1 dtex or more, and more preferably in the range of 0.1 to 60 dtex. If the fineness is less than 0.1 dtex, the fibers may not be sufficiently bound to each other. If the fineness exceeds 60 dtex, the fiber sheet 11 is impregnated with the melt of the low melting point fiber and becomes hard. There is a risk that a good texture cannot be obtained. The fiber length of the low melting point fiber is preferably in the range of 20 to 100 mm. When the fiber length is less than 20 mm, the above-mentioned normal fibers may not be sufficiently bound to each other. When the fiber length exceeds 100 mm, the fibers are usually bound excessively and the cushioning property of the fiber sheet 11 is increased. There is a risk of damage. The melting point of the low-melting fiber is preferably 180 ° C. or lower. When the melting point exceeds 180 ° C., the low melting point fiber may not be melted when heated to bind the fibers.

(Mixing ratio)
In the mixed fiber, the mixing ratio of the normal fiber and the low-melting fiber is preferably in the range of 10 to 65 parts by mass of the low-melting fiber with respect to 100 parts by mass of the normal fiber. When the low melting point fiber is less than 10 parts by mass with respect to 100 parts by mass of the normal fiber, there is a possibility that the normal fiber, which is the fiber 14 serving as the core material, cannot be sufficiently bound, and exceeds 65 parts by mass. The melt of the low-melting fiber becomes a lump and hardens the fiber sheet 11, so that a good texture may not be obtained.

[Fiber sheet]
As the fiber sheet 11, it is desirable to use a nonwoven fabric produced by the thermal bond method using the mixed fiber.
The thermal bond method is a method in which the low melting point fibers contained in the mixed fibers are melted by heating, and the fibers (synthetic fibers and inorganic fibers) serving as the core material are bonded to each other. Moreover, in the nonwoven fabric of the thermal bond method, when forming the fiber into a thin sheet-like web, by using a carding method in which the web is formed while mechanically combing the fiber lump, and randomly using an air flow There is an airlaid system in which a web is formed by entanglement of fibers, but any system may be used.
The fiber sheet 11 desirably has a thickness of 10 to 50 mm. When the thickness is less than 10 mm, sufficient cushioning properties as the cushioning sheet 10 cannot be obtained, and the resin adhesion layer 12 is kept within a predetermined range (within 25% of the thickness) of the fiber sheet 11. There is a risk that it will not be possible. When the thickness exceeds 50 mm, it becomes impossible to suppress the sag of the cushioning property even if the resin adhesion layer 12 is provided.
The fiber sheet 11 has a ventilation resistance of 0.01 to 0.1 kPa · s / m. When the airflow resistance is less than 0.01 Pa · s / m, the synthetic resin binder is excessively soaked and impregnated in the fiber sheet 11, so that the resin adhesion layer 12 is within a predetermined range of the thickness of the fiber sheet 11 (thickness). Within 25% of the total). When the airflow resistance exceeds 0.1 kPa · s / m, the synthetic resin binder cannot enter the fiber sheet 11 and hardens into a film shape on the surface of the fiber sheet 11, so that the texture becomes worse.
The fiber sheet 11 preferably has a weight per unit area of 100 to 500 g / m ² . When the weight per unit area is less than 100 g / m ² , the obtained cushioning sheet 10 may be inferior in strength. When it exceeds 500 g / m ² , the handling property is inferior and difficult to handle. There is a risk of becoming.
The fiber sheet 11 desirably has a density of 2 to 50 kg / m ³ . When the density is less than 2 kg / m ³ , the ventilation resistance may not be within the range of 0.01 to 0.1 kPa · s / m, and the obtained cushioning sheet 10 is excessively soft and cushioning. If the density exceeds 50 kg / m ³ , the ventilation resistance may not be in the range of 0.01 to 0.1 kPa · s / m, and the obtained cushioning sheet 10 It may be too hard and inferior in cushioning properties .

[Ventilation resistance]
The ventilation resistance R (Pa · s / m) is a scale representing the degree of ventilation of the breathable material. The measurement of the ventilation resistance R is performed by a steady flow differential pressure measurement method. As shown in FIG. 3, the test piece T is arranged in the cylindrical air passage W, and the pressure in the air passage W on the start point side of the arrow in the figure in a state of a constant air flow V (the direction of the arrow in the figure). By measuring the pressure difference between P1 and the end point P2 of the arrow in the figure, the ventilation resistance R can be obtained from the following equation.
R = ΔP / V
Here, ΔP (= P1−P2): Pressure difference (Pa), V: Air flow rate per unit area (m ³ / m ² · s). The ventilation resistance R (Pa · s / m) is in a relationship of air permeability C (m / Pa · s) and C = 1 / R.
The ventilation resistance can be measured by, for example, an air permeability tester (product name: KES-F8-AP1, manufactured by Kato Tech Co., Ltd., steady flow differential pressure measurement method).

[Resin adhesion layer]
As described above, in the cushioning sheet 10 according to the present embodiment, the synthetic resin binder applied to both the upper surface and the lower surface of the fiber sheet 11 enters the fiber sheet 11, and the resin 13 of the synthetic resin binder is the above. It has the resin adhesion layer 12 provided by hardening on the surface of the fiber 14. The synthetic resin (resin 13) contained in the synthetic resin binder is mainly a thermosetting resin and / or a pseudo thermoplastic resin.
In the resin adhesion layer 12, the resin 13 is granular and adhered to the surface of the fibers constituting the fiber sheet 11, that is, the fibers 14 (the normal fibers) serving as the core material. Then, the resin 13 which is granular and adhered to the surface of the fiber 14 reinforces the fiber 14 without hindering the elasticity of the fiber 14, thereby sufficiently increasing the rigidity of the fiber 14 itself. The resin adhesion layer 12 suppresses cushioning sag due to long-term use of the cushioning sheet 10 and the like.
The thickness of the resin adhesion layer 12 is preferably within a range from the surface of the fiber sheet 11 to 25% of the thickness of the fiber sheet 11. When the thickness of the resin adhesion layer 12 is more than 25% of the thickness of the fiber sheet 11, the hardness due to the resin adhesion layer 12 is superior to the softness due to the fiber sheet 11, The cushioning property of the cushioning sheet 10 is impaired.
In the present embodiment, the resin adhesion layers 12 are provided on both the upper surface and the lower surface of the fiber sheet 11, but the thickness of each resin adhesion layer 12 is determined from the upper surface or the lower surface of the fiber sheet 11, respectively. The thickness is within a range of up to 25% of the thickness of the fiber sheet 11. That is, when the resin adhesion layers 12 are provided on both surfaces of the fiber sheet 11, the total thickness of the resin adhesion layers 12 is within a range of up to 50% of the thickness of the fiber sheet 11.
In the resin adhesion layer 12, the resin 13 preferably has a particle size of 0.05 to 1.5 mm. When the particle size is less than 0.05 mm, the resin 13 attached to the surface of the fiber 14 cannot sufficiently reinforce the fiber 14, and the cushioning properties such as strain and beam are inferior. There is a risk that it will not be possible to obtain a good texture. When the particle diameter exceeds 1.5 mm, the hardness of the resin 13 attached is superior to the rigidity exhibited by the fibers 14, and the elastic deformation of the fibers 14 is hindered. There is a risk that the property will be impaired.
The coating amount of the resin 13 when the resin adhesion layer 12 is provided on one side of the fiber sheet 11 is 10 to 50 g / m ² (Dry) . The coating amount of the resin 13 in the case where the resin adhesion layer 12 on both sides of the fiber sheet 11 shall be the 20~100g ^/ m 2 (Dry). When the coating amount is less than 10 g / m ² (Dry) on one side and 20 g / m ² (Dry) on both sides, it becomes difficult to provide the resin adhesion layer 12 that can reinforce the fibers 14. amount on one side ^50g / m 2 (Dry), if it exceeds 100g ^/ m 2 (Dry) on both sides, there is a possibility that the thickness of the resin adhesion layer 12 exceeds 25% of the thickness of the fiber sheet 11.

(Thermosetting resin)
Examples of the thermosetting resin include urethane resin, melamine resin, thermosetting acrylic resin, particularly thermosetting acrylic resin that cures by forming an ester bond by heating, urea resin, phenol resin, epoxy resin, thermosetting type Polyester or the like is used, but urethane resin prepolymer, urea resin prepolymer (initial condensate), phenol resin prepolymer (initial condensate), diallyl phthalate prepolymer, acrylic oligomer, polyisocyanate that produce the synthetic resin. Synthetic resin precursors such as prepolymers such as narate, methacrylic ester monomers and diallyl phthalate monomers, oligomers and monomers may be used.
When the fiber sheet 11 is applied and impregnated, the thermosetting resin is used in a liquid state by being in the form of an aqueous solution, an aqueous emulsion, an aqueous dispersion, or in the form of an organic solvent solution. The If desired, a certain amount of thermoplastic resin may be mixed and used. Further, two or more of the above thermosetting resins or synthetic resin precursors may be used in combination.

(Pseudo thermoplastic resin)
The pseudo thermoplastic resin is
(A) 5 to 100% by weight of a polymer obtained by radical polymerization consisting of an ethylenically unsaturated acid anhydride or an ethylenically unsaturated dicarboxylic acid in which a carboxylic acid group can form an acid anhydride group;
(B) an alkanolamine having at least two hydroxyl groups;
A phosphorus-containing reaction accelerator less than 1.5% by mass with respect to the sum of (A) + (B);
An aqueous binder containing no formaldehyde.
The aqueous binder is generally provided in the form of an aqueous emulsion, an aqueous solution, a water-soluble organic solvent solution such as isopropanol, ethanol, or glycol, or a mixed solvent solution of water and the water-soluble organic solvent. It hardens | cures by esterification reaction of the acid contained in A) and the hydroxyl group contained in alkanolamine (B), water solubility changes to water insolubility, and thermoplasticity changes to pseudo thermoplasticity.
The pseudo thermoplastic resin is currently marketed by BASF under the trade name Acrodur, and there are 950L, DS3530 as an aqueous solution type, and 958D as an aqueous emulsion type.
The above acrodure starts crosslinking by the esterification reaction at a temperature of about 120 ° C. or higher and cures at a temperature of 160 ° C. or higher. However, it has sufficient hardness even in a thermoplastic state before crosslinking and is easy to handle. Moreover, during thermoforming, the hardness is reduced by heating and becomes temporarily thermoplastic (pseudo-thermoplastic), exhibits good moldability, and high molding accuracy is obtained. Moreover, since the cross-linking of the acrodure is based on an esterification reaction, there is an advantage that only water is by-produced and no harmful substances such as formaldehyde are by-produced.
Two or more of the above-mentioned pseudo thermoplastic resins, for example, an aqueous solution type and an aqueous emulsion type may be mixed, or other thermoplastic resin aqueous emulsions and the like may be mixed.
The details of the pseudo thermoplastic resin are described in, for example, JP 2000-506940 A.

[Additives, mixtures]
In the cushioning sheet 10, the following additives and mixtures may be added and mixed as desired.

(Flame retardants)
A flame retardant may be added to the fiber sheet 11. Examples of the flame retardant include phosphorus flame retardant, nitrogen flame retardant, sulfur flame retardant, boron flame retardant, bromine flame retardant, guanidine flame retardant, phosphate flame retardant, phosphate ester flame retardant, amino acid Resin-based flame retardant, expanded graphite, etc.
In the present invention, it is particularly desirable to use a powdery solid flame retardant which is hardly soluble or insoluble in water. The powdery solid flame retardant which is hardly soluble or insoluble in water gives the cushioning sheet 10 flame resistance excellent in water resistance and durability.

(Other)
The synthetic resin of the synthetic resin binder is not only mainly a thermosetting resin and / or a pseudo-thermoplastic resin, but for the purpose of modification, for example, an acrylate resin, a vinyl acetate resin, a styrene resin Alternatively, a mixture of a thermoplastic resin having a glass transition point of 20 ° C. or higher, such as vinyl acetate / ethylene resin, and the like, and a thermosetting resin and / or a pseudo thermoplastic resin may be used.
The synthetic resin binder further includes calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, calcium sulfite, calcium phosphate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, magnesium oxide, titanium oxide, iron oxide, zinc oxide. , Alumina, silica, colloidal silica, mica, diatomite, dolomite, gypsum, talc, clay, asbestos, mica, calcium silicate, bentonite, white carbon, carbon black, iron powder, aluminum powder, glass powder, stone powder, blast furnace slag, Inorganic fillers such as fly ash, cement, zirconia powder; natural rubber or derivatives thereof; styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, isoprene rubber, isoprene Synthetic rubber such as N-isobutylene rubber; water-soluble polymers such as polyvinyl alcohol, sodium alginate, starch, starch derivatives, glue, gelatin, blood powder, methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, polyacrylate, polyacrylamide, and natural gum Organic fillers such as wood powder, walnut powder, coconut powder, wheat flour and rice flour; higher fatty acids such as stearic acid and palmitic acid; higher alcohols such as palmityl alcohol and stearyl alcohol; butyryl stearate and glycerin monostearate Esters of fatty acids such as: fatty acid amides; natural waxes such as carnauba wax, synthetic waxes; separation of paraffins, paraffin oil, silicone oil, silicone resin, fluororesin, polyvinyl alcohol, grease, etc. Agents; organic foaming agents such as azodicarbonamide, dinitrosopentamethylenetetramine, P, P'-oxybis (benzenesulfonylhydrazide), azobis-2,2 '-(2-methylgropionitrile); sodium bicarbonate, Inorganic foaming agents such as potassium bicarbonate and ammonium bicarbonate; hollow particles such as shirasu balloon, pearlite, glass balloon, foam glass and hollow ceramics; plastic foam and foam particles such as foamed polyethylene, foamed polystyrene and foamed polypropylene; pigments , Dye, antioxidant, antistatic agent, crystallization accelerator, phosphorus compound, nitrogen compound, sulfur compound, boron compound, bromine compound, guanidine compound, phosphate compound, phosphate ester compound, Flame retardants such as amino resins, flame retardants, water repellents, oil repellents, insect repellents, preservatives, Add, mix phthalates plasticizers such as DBP, DOP, dicyclohexyl phthalate, and other plasticizers such as tricresyl phosphate, etc. Also good.
Examples of the water and oil repellents include natural wax, synthetic wax, fluororesin, and silicon resin.

[Production method of cushioning sheet]
In producing the cushioning sheet 10 of the present embodiment, first, after obtaining a web composed of mixed fibers obtained by mixing low-melting fibers at a ratio of 10 to 65 parts by mass with respect to 100 parts by mass of normal fibers, The low melting point fiber is melted by pressing with a heating roll, and the thickness is 10 to 50 mm and the airflow resistance is 0.01 to 0.1 kPa by a thermal bond method for binding the normal fibers constituting the web. -The fiber sheet 11 which consists of a nonwoven fabric of s / m is manufactured.
Thereafter, a synthetic resin binder composed of an aqueous solution and / or an aqueous emulsion of the thermosetting resin and / or the pseudo thermoplastic resin is applied to both surfaces of the fiber sheet 11 by spray coating, and the synthetic resin is applied to the fiber sheet 11. The binder resin 13 is adhered within a range from the surface of the fiber sheet 11 to 25% of the thickness of the fiber sheet 11.
And after making the said resin 13 adhere to the said fiber sheet 11, this fiber sheet 11 is heated, this resin 13 is hardened, and the cushioning sheet | seat 10 is obtained.
The spray application includes an air spray method in which a resin liquid is sprayed together with air, and an airless spray method in which only the resin liquid is sprayed in a mist form. In the present invention, the air spray method is used. That is, in the case of the airless spray method, since only the resin is sprayed in a fine mist form, the sprayed resin is not almost granular and covers the surface of the fiber 14 so as to be painted. The elastic deformation of 14 is hindered, and even if it becomes granular, it becomes a particle having a very small particle size, so that it is difficult to adjust the particle size.
On the other hand, in the case of the air spray method, the air contained in the resin to be sprayed rounds the resin to make it granular, so that the resin attached to the surface of the fiber 14 tends to be spherical. Further, in the case of the air spray method, the amount of air can be adjusted at the time of spraying. Therefore, by adjusting the amount of air, the resin liquid is sprayed so that the particle size becomes 0.05 to 1.5 mm.

[Use of cushioning sheet]
The cushioning sheet 10 is not particularly limited. For example, the cushioning sheet 10 may be, for example, a car seat cushion material, a floor cushion material, a household chair cushion material, or a packing cushion material. Can be mentioned. When the cushioning sheet 10 is used as a cushioning material for automobile seats or chairs, a plurality of cushioning sheets 10 are usually laminated and used in a predetermined shape. When a cushion material for an automobile floor is used, a fiber material such as felt or velor is laminated on the upper surface of the cushioning sheet 10.

[Sound absorbing material]
As shown in FIG. 2, the cushioning sheet 10 can be made the sound absorbing material 20 by laminating a sound absorbing sheet 21 on one side thereof.
The sound absorbing sheet 21 is configured by laminating a fiber sheet as a surface layer material 23 on one side of a paper material sheet 22.
Further, the paper material sheet 22 and the surface layer material 23 are bonded via a breathable adhesive layer (not shown) so that noise can pass through without being inhibited.
When the noise passes through the sound absorbing sheet 21, the sound absorbing sheet 21 vibrates fibers constituting the paper material sheet 22 and the surface layer material 23, particularly the porous pulp fibers of the paper material sheet 22, respectively. Thus, the buffer sound absorbing performance can be exhibited.
The thickness of the sound absorbing sheet 21 is preferably in the range of 0.2 to 2.0 mm from the viewpoint of being attachable to various objects of use and satisfying a predetermined strength. If the thickness is less than 0.2 mm, the sound-absorbing sheet 21 may be easily broken and may not satisfy the predetermined strength. If the thickness exceeds 2.0 mm, it may not be attached depending on the object of use. There is a possibility that the target of use will be limited.
The air-permeable adhesive layer is, for example, a hot melt adhesive powder spread, a spider web-like hot melt adhesive layer interposed, a solution or aqueous emulsion spray coating, a point application by silk printing or offset printing, or the like. It is formed by a linear coating method or the like.
Further, the sound absorbing material 20 shown in FIG. 2 has the sound absorbing sheet 21 laminated on only one side of the cushioning sheet 10, but the present invention is not limited thereto, and the sound absorbing sheet 21 may be laminated on both sides of the cushioning sheet 10. .

[Paper sheet]
The paper material sheet 22 is a main member for the sound absorbing sheet 21 to exhibit a buffer sound absorbing performance, and includes only porous pulp fibers or porous pulp fibers and normal fibers (nonporous pulp fibers). Made of mixed fibers. When mixed fibers are used for the paper sheet 22, the mixing ratio of the porous pulp fibers in the mixed fibers is 90% by mass or more from the viewpoint of making the sound absorbing material 20 lightweight and exhibiting excellent buffer sound absorbing performance. Yes, desirably 95% by mass or more.
The paper material sheet 22 is obtained by applying a papermaking method, a needle punching method, or the like to porous pulp fibers or mixed fibers.

The mass per unit area (weight per unit area) of the paper material sheet 22 is desirably 10 to 50 g / m ² from the viewpoint of satisfying the required strength while maintaining the required air permeability. When the basis weight is less than 10 g / m ² , the strength of the paper material sheet 22 is reduced, and the paper material sheet 22 is easily broken during molding. When the weight per unit area exceeds 50 g / m ² , the air permeability decreases and the buffer sound absorption performance deteriorates, and the moldability decreases and wrinkles easily occur.

  Specific examples of the paper material sheet 22 include flat paper having no wrinkles or irregularities on the surface, creped paper having crimped wrinkles formed on the surface, embossed paper having many irregularities formed on the surface, Examples include crepe embossed paper on which both wrinkles and irregularities are formed. Among these, creped paper and crepe-embossed paper are desirable from the viewpoint of excellent buffer sound-absorbing performance and excellent formability due to excellent stretchability.

(Porous pulp fiber)
The porous pulp fiber is made of non-wood plant fiber and / or wood plant fiber, and is made of softwood or hardwood chips, and the beating degree is JIS P 8121-1995. Canadian standard freeness specified by Canadian Standard Freeness and having a range of 350 to 650 ml (CSF).
The beating is performed by a conical refiner, a disc refiner, or the like. When the beating degree of the pulp fiber exceeds 650 ml (CSF), the pulp fiber is not sufficiently crushed or concentrically loosened, and the porous structure due to the large number of pores opening on the surface of the pulp fiber becomes insufficient. The porosity is reduced, and the sound absorbing performance of the sound absorbing material 3 is adversely affected. On the other hand, if it is less than 350 ml (CSF), the pulp fibers are fibrillated and fragmented, and the number of fine fibers increases. Therefore, the density of the paper sheet made of such pulp fibers increases, and the sound absorbing properties of the sound absorbing material 3 are adversely affected. It is.

(Normal fiber)
Examples of the normal fibers (nonporous pulp fibers) include, for example, polyester fibers, polyethylene fibers, polypropylene fibers, polyamide fibers, acrylic fibers, urethane fibers, polyvinyl chloride fibers, polyvinylidene chloride fibers, and organic synthetic fibers such as acetate fibers, Biodegradable fiber (polylactic acid fiber) made of starch extracted from plants such as corn and sugarcane, natural fiber such as pulp, cotton, palm fiber, hemp fiber, bamboo fiber, kenaf fiber, glass fiber, carbon fiber, ceramic fiber Inorganic fibers such as asbestos fibers, or one type or two or more types of recycled fibers obtained by defibrating scraps of fiber products using these fibers are used. Desirable fibers include recycled polyester fibers regenerated from polyester product waste such as PET bottles.

[Surface material]
The surface layer material 23 is provided mainly for the purpose of reinforcing the paper material sheet 22, and the surface layer material 23 improves the buffer sound absorption performance of the sound absorbing sheet 21 by using a fiber material. ing.
As the material of the surface layer material 23, a sheet having air permeability such as a nonwoven fabric made of fibers or a knitted fabric, that is, a fiber sheet (hereinafter also referred to as “fiber material”) is used.
As the fiber used for the fiber material, those mentioned in the normal fiber of the paper material sheet can be used, and in addition, for example, a melting point such as ceramic fiber, asbestos fiber, stainless steel fiber, aramid fiber, etc. If one having a temperature of 250 ° C. or higher is used, heat resistance can be imparted. Further, since the fiber material is a fiber sheet, the fiber sheet 11 shown by the cushioning sheet 10 can be used.
The mass per unit area (weight per unit area) of the fiber material used for the surface layer material 23 is preferably in the range of 15 to 200 g / m ² . When the mass per unit area is less than 15 g / m ² , the surface material 23 may not be able to reinforce the paper material sheet 22 appropriately. When the mass per unit area exceeds 200 g / m ² , the weight increases and the sound absorbing sheet 21 may become heavy.

[Apply or impregnate synthetic resin]
At least one of the paper material sheet 22 and the surface layer material 23 may be coated and / or impregnated with a synthetic resin or the like for the purpose of imparting rigidity, formability, or adjusting airflow resistance, Further, a synthetic resin or the like may be mixed at the time of manufacturing the fiber material used for the surface layer material 23. Examples of the synthetic resin include an existing thermoplastic resin and / or an existing thermosetting resin.

[Ventilation resistance]
The ventilation resistance of the sound absorbing material 20 is desirably set to 0.4 to 5.0 kPa · s / m. When the ventilation resistance is less than 0.4 kPa · s / m, the sound absorbing material 20 cannot exhibit sufficient buffer sound absorbing performance against noise. When the airflow resistance exceeds 5.0 kPa · s / m, noise is increased by reflecting the sound absorbing material 20 without entering the sound absorbing material 20.
The ventilation resistance of the sound absorbing sheet 21 is desirably set to 0.2 to 3.0 kPa · s / m. When the ventilation resistance is less than 0.2 kPa · s / m, it becomes difficult to make the ventilation resistance of the sound absorbing material 20 within the range of 0.4 to 5.0 kPa · s / m. There is a possibility that sufficient buffer sound absorbing performance against noise may not be exhibited. When the ventilation resistance exceeds 3.0 kPa · s / m, it becomes difficult to make the ventilation resistance of the sound absorbing material 20 within the range of 0.4 to 5.0 kPa · s / m, and the inside of the sound absorbing sheet 21. There is a risk that noise will increase due to reflection without noise entering.
The airflow resistance of the paper material sheet 22 is appropriately set so that the airflow resistance when the surface layer material 23 is laminated to form the sound absorbing sheet 21 is in the range of 0.2 to 3.0 kPa · s / m. It is preferably in the range of 0.1 to 2.5 kPa · s / m. When the ventilation resistance of the paper sheet 22 is less than 0.1 kPa · s / m, the ventilation resistance of the sound absorbing sheet 21 may not be less than 0.2 kPa · s / m, and exceeds 2.5 kPa · s / m. In such a case, the airflow resistance of the sound absorbing sheet 21 may exceed 3.0 kPa · s / m.
In addition, adjustment of this ventilation resistance can be adjusted with the entanglement of fibers, a fabric weight, and a density, and it can adjust with the application quantity or impregnation quantity of a synthetic resin besides these.

[Filter sheet]
The cushioning sheet 10 can be used as a filter sheet.
When the cushioning sheet 10 is used as a filter sheet, the cushioning sheet 10 may be used as it is, or the paper material sheet 22 or the surface layer shown in the sound absorbing material 20 on one side or both sides of the cushioning sheet 10. The material 23 may be laminated for the purpose of improving and reinforcing the shock absorbing performance.

[Manufacture of cushioning sheets]
[Example 1]
Polyethylene terephthalate fiber (fineness: 2.2 dtex, fiber length: 75 mm) as normal fiber is 80% by mass, and low melting point fiber (fineness: 2.0 dtex, fiber length: 75 mm) made of polyethylene terephthalate having a melting point of 160 ° C. is 20% by mass, The fiber sheet 11 which is the nonwoven fabric by the thermal bond method was manufactured using the mixed fiber which consists of. The fiber sheet 11 had a thickness of 20 mm, a basis weight of 174 g / m ² , a density of 8.7 kg / m ³ , and a ventilation resistance of 0.024 kPa · s / m.
Next, a resin solution prepared by adding water to a mass of 20% by mass of Acrodure 950L, which is a pseudo-thermoplastic resin, is 25 g / m in terms of solid content on one side of the fiber sheet 11. ² was applied by an air spray method and dried by heating at 150 ° C. to cure the acrodure 950 L, thereby producing a cushioning sheet 10. In this cushioning sheet, the thickness of the resin adhesion layer 12 from the surface layer was 3 to 5 mm, and the ventilation resistance was 0.033 kPa · s / m. In the resin adhesion layer 12, the resin adhered in a spherical shape to the fiber surface, and the particle size of the spherical resin was approximately 0.1 to 1.0 mm.
The cushioning sheet 10 produced as described above has good cushioning properties, and when used as a filter sheet in a paint drying furnace booth, the filter hangs even at a high temperature (about 180 ° C.) during paint heating and drying. There was no dust collection property.

  The cushioning sheet of the present invention, the sound-absorbing sheet comprising the cushioning sheet, or the filter sheet is easy to manufacture, has good cushioning properties, and does not easily sag even when used for a long time. Industrially available.

DESCRIPTION OF SYMBOLS 10 Cushion sheet | seat 11 Fiber sheet 12 Resin adhesion layer 13 Resin 14 Fiber 20 Sound absorption sheet 21 Sound absorption material 22 Paper material sheet 23 Surface layer material

Claims (9)

Uses mixed fibers in which low-melting fibers of thermoplastic fibers having a melting point of 180 ° C. or less are mixed at a ratio of 10 to 65 parts by mass with respect to 100 parts by weight of normal fibers which are thermoplastic fibers having a melting point of 200 ° C. or more. Then, the fibers are bonded to each other by heating melt of low melting point fibers contained in the mixed fiber, the thickness is set to 10 to 50 mm, and the ventilation resistance is adjusted to 0.01 to 0.1 kPa · s / m . was the air spray method on a synthetic resin binder on one side or both sides of the fiber sheet, in the case of one-sided upper surface of the thick the fiber sheet to set the coating amount to 10~50g / m 2 ^(Dry) and resin adhesion layer or The fiber sheet is applied from the lower surface to the range of 25% of the thickness of the fiber sheet. In the case of both surfaces, the coating amount is set to ²⁰ to 100 g / m ² (Dry), and the thickness of the resin adhesion layer is the fiber. 50% of sheet thickness Was applied in the range of up to, cushioning sheet having a particle size of the resin in the resin adhesion layer is characterized in that by adhering so that the granular 0.05 to 1.5 mm. The cushioning sheet according to claim 1, wherein the synthetic resin of the synthetic resin binder is a thermosetting resin and / or a pseudo thermoplastic resin. The cushion according to claim 1 or 2 , wherein the synthetic resin of the synthetic resin binder is a mixture of a thermosetting resin and / or a pseudo thermoplastic resin and a thermoplastic resin having a glass transition point of 20 ° C or higher. Sex sheet. The cushioning sheet according to any one of claims 1 to 3 , wherein the normal fiber is a thermoplastic fiber having a fineness of 1.0 dtex or more and a fiber length of 20 to 100 mm . The cushioning sheet according to any one of claims 1 to 4 , wherein the low melting point fiber is a thermoplastic fiber having a fineness of 0.1 dtex or more and a fiber length of 20 to 100 mm . On one side or both sides of the cushioning sheet according to any one of claims 1 to 5 ,
The beating degree is JIS P 8121-1995. Laminated with a fiber sheet on one or both sides of a paper sheet containing 90% by mass or more of a porous pulp fiber with a Canadian standard freeness specified by Canadian Standard Freeness in the range of 350 to 650 ml (CSF). A sound-absorbing sheet having a ventilation resistance set in a range of 0.2 to 3.0 kPa · s / m.
A sound-absorbing material characterized by being laminated. A filter comprising the cushioning sheet according to any one of claims 1 to 5 . A web in which low-melting fibers are mixed in a ratio of 10 to 65 parts by mass with respect to 100 parts by mass of normal fibers is pressed with a heating roll to melt the low-melting fibers and constitute the web. Usually, fibers are bound to form a fiber sheet made of a nonwoven fabric having a thickness of 10 to 50 mm and a ventilation resistance of 0.01 to 0.1 kPa · s / m, and a synthetic resin binder is sprayed on the fiber sheet by an air spray method. to, any one of claims 1 to 5, characterized in that allowed to adhere to the fiber sheet to a particle size of synthetic resin of the synthetic resin binder is granulated 0.05~1.5mm The manufacturing method of the cushioning sheet of description. The said synthetic resin binder is a manufacturing method of the cushioning sheet | seat of Claim 8 made to adhere in the range to 25% of thickness from the both surfaces of the said fiber sheet.