JPH0562652B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a sheet that cushions vibrations and shocks. That is, the impact cushioning sheet of the present invention can be used as containers for easily damaged items, protective materials for precision equipment, housings that require vibration damping, covering materials for piping such as ducts, base members for precision equipment, and audio-related products. Vibration and shock buffering sheet that can be applied to vibration damping materials for buildings, floor vibration damping members for buildings, vibration damping insulation materials, vibration damping members for vehicles and ships, damping members for preventing electromagnetic damage, vibration damping members for preventing static electricity, etc. It is related to. The vibration and impact cushioning sheet of the present invention has both a convex air chamber having a closed cell structure and a viscoelastic body filled in a recess formed between the convex parts, that is, the air chamber and the viscoelastic body. This is an impact cushioning sheet that not only takes advantage of the excellent vibration damping and shock mitigation performance of each, but also has excellent compression properties and compression recovery properties that can only be achieved by combining both. In recent years, technological progress has been remarkable, and various developments are being carried out in various fields, but in particular, the means to prevent vibrations are technically difficult, and a large amount of money is spent on prevention measures. At present, it is desired to have a means to perform vibration at low cost. In other words, in recent years, places that used to be relatively tolerant of vibrations have become more premium-oriented, and finally, equipment that is extremely sensitive to vibrations and buildings, vehicles, ships, etc. are now seeking quieter spaces. The demand for this is increasing. Therefore, the inventors of the present invention wanted to obtain a member with high vibration damping effect at low cost, and after much trial and error, they decided to use a viscoelastic material to fill the air chambers in the convex portions of the sheet and the concave portions as described above. As a result, the present invention was completed based on the knowledge that it is possible to obtain a shock-absorbing sheet that has both the characteristics of air and the characteristics of a viscoelastic material, and has excellent compression and restoring characteristics as a synergistic effect. In other words, the shock-absorbing sheet of the present invention utilizes the characteristics of air and the viscoelastic material to the fullest in one layer, which has excellent vibration damping properties, damping properties, and compression properties of air. It is something. As is conventionally known, examples of impact mitigation materials include foams such as styrofoam and urethane foam, cardboard, hollow plastic laminates, and air-containing plastic sheets, which are also a part of the present invention. It is known that even a small stress can easily cause compression deformation, and the impact can be easily alleviated. However, because these restoring forces or material strength are weak, once compressive deformation is applied, there are problems in that it is difficult to restore or break, and there is a major drawback in that the function is lost. There are also cushioning rubbers, anti-vibration rubbers, non-repulsion rubbers, etc., but these generally require a vulcanization process, making them expensive and difficult to use for general use, have a high specific gravity, which leads to an increase in weight, and have a high elastic modulus, making them difficult to use when impacting. It has drawbacks such as not being able to sufficiently absorb energy and vibrational energy. In addition, there are vibration damping materials such as insulators used in audio equipment, etc., but they have the disadvantage that they must be sufficiently tall to contain a large amount of air, and the structure is complex and expensive. ing. Additionally, the measures currently being taken to deal with floor impact noise are as follows:
Compressed glass wool, asbestos, particle board,
The floor can be constructed by combining several types of rubber boards, inorganic boards, plywood, etc., or by floating such combinations from the floor slab, and in addition, sound absorbing materials can be placed between the floor surface and the ceiling of the lower floor. Currently, the ceiling is made of vibration-proof rubber to create a suspended ceiling, and the overall effect of the floor and lower floor ceiling is used to alleviate floor impact noise. However, the above method requires a large number of raw materials,
Costs increase due to raw material costs, material loss during construction, and a large number of construction steps. In addition, the total thickness of the floor materials used to mitigate floor impact noise has become extremely thick, forcing the eaves of the building to be raised, the living space to be narrow, or the number of floors to be reduced. If the number of floors is secured and the living space is the same, the disadvantage is that the increased height of the eaves will add to the construction cost. The inventors of the present invention solved the above-mentioned drawbacks, and as a result of intensive research aimed at creating a restraining type impact cushioning sheet that is low cost, reduces impact energy with a thin film, and is easy to work with, the inventors found that a viscoelastic body and an air-filled part Each of these film base materials has excellent impact mitigation properties when used alone, and when both are used together, they not only exhibit the performance of repeatedly absorbing large impact energy, but also overcome the drawbacks of using them alone. As a result of various tests, we have completed the present invention. The impact cushioning sheet of the present invention has a configuration in which the concave portions of a film base material in which convex portions filled with air and concave portions made only of film are arranged alternately, and/or the entire surface thereof is filled with a viscoelastic substance. , the volume ratio of the air volume of the air-filled convex part to the viscoelastic body filled in the film-only concave part is convex part: concave part = 2:
The ratio is 8 to 8:2, and the height of the convex portion is 2 to 10 mm. In addition, the present invention provides a film substrate in which a viscoelastic body that fills the recesses and/or the entire surface of the film base material in which convex portions filled with air and recesses made only of the film are alternately arranged, undergoes a curing reaction, The substance after the curing reaction is 80
It is characterized by retaining its shape even when heated to ℃, and has a hardness of 80 or less on a JIS-A hardness tester at 20℃. Furthermore, the present invention provides that the viscoelastic body fills the recesses and/or the entire surface of the film base material, in which the convex portions filled with air and the recesses made only of the film are arranged alternately, and It is characterized by being a crosslinked viscoelastic body obtained by subjecting a main ingredient having a telechelic polymer as a basic component and a curing agent having two or more isocyanate groups per molecule to a curing reaction at room temperature. Furthermore, in the present invention, the crosslinked viscoelastic material filled in the recesses of the film base material, in which the convex parts enclosing air and the recessed parts containing only the film are arranged alternately, and/or the entire surface thereof, It is characterized by being a crosslinked viscoelastic body obtained by subjecting a main ingredient consisting of liquid polybutadiene, asphalt, and a plasticizer to a curing reaction at room temperature with a curing agent having two or more isocyanate groups per molecule. In other words, conventionally, when viscoelastic materials are used alone, they are expensive and unsuitable for general-purpose impact cushioning sheets, and in order to achieve thickness accuracy after solidification or curing, manufacturing The drawback was that there were many restrictions and the cost was high when equipment was taken into account. On the other hand, when a protrusion sheet base material with an air-enclosed portion is used alone, as there is no material to protect the protrusion thin film as described above, pressure may be applied locally or even over a large area. It has the disadvantage that it is easily damaged when subjected to a small impact force, and it no longer functions as an impact cushioning sheet. or,
A protrusion sheet whose convex portions are covered with a thin film has a slightly higher load capacity than a protrusion sheet, but it will break even with a relatively small impact force, and once it is damaged, it will not have any impact mitigation properties and will not have sufficient performance. It's hard to say what I did. As a result of repeated trial and error in order to solve both of the above-mentioned drawbacks, the present inventors have found that by filling the recesses and/or the entire surface of a plastic film having independent convex air chambers with a viscoelastic substance, the impact can be reduced. It was found that a product with excellent elasticity and compression properties can be obtained. In other words, the reason for the excellent impact mitigation properties is that the air-filled portion becomes an air bag and is easily compressed and deformed, and the viscoelastic material filled in the recesses adheres closely to the convex portions of the film base material.
Because it is three-dimensionally restrained, in addition to the impact energy absorption performance of the viscoelastic material itself, the deformation of the convex part of the film that forms the air bag and the displacement of the viscoelastic material increase, which further reduces the impact energy. It is thought that the energy absorption performance has increased. In addition, in terms of compression characteristics, when an impact is applied, the air bladder, which is a convex part of the film, is compressed, and the viscoelastic body is compressed even more. Although it easily deforms under very small displacements, For compression, the stress of the compressed air in the convex air bag and the compressive stress of the viscoelastic body act, and in order to increase the deformation, a larger force is required, so the displacement is larger than necessary. You can avoid doing that. Furthermore, it has been found that when the compressive load is released, the restoring force of the viscoelastic body and the restoring force of the compressed air are integrated, and a very quick restoration is possible. In addition, although viscoelastic materials are generally susceptible to changes in hardness due to temperature and are crosslinked, they tend to be more susceptible to changes in hardness due to temperature changes, but at high temperatures, air expansion causes a decrease in compressive force due to a decrease in the hardness of the viscoelastic material. Conversely, at low temperatures, air contraction suppresses the increase in compressive strength due to increased hardness of the viscoelastic material, and it also has the advantage of being used as a shock absorbing sheet in that it reduces changes in performance due to temperature changes. In addition, in terms of cost, since one side is a film, when processing the sheet of the present invention, the handling work is very easy and it is very effective in shortening the processing time or working time. However, in manufacturing the sheet of the present invention, it is possible to process the sheet into a long length, which is advantageous in terms of cost. In addition, in the pasting process, functions such as impact resistance, vibration damping properties, and heat insulation properties can be imparted to the impact surface by simply pasting it with the adhesive force of the viscoelastic body itself or with an adhesive. The air-filled section does not require a viscoelastic body, so it is suitable for cost reduction. Next, the cross-sectional structure of the impact cushioning sheet of the present invention will be described. As shown in FIGS. 1 and 3, a plastic sheet is filled with a viscoelastic material in the concave portions between the convex portions of a plastic film having independent convex air chambers, and/or the entire surface is filled with a vibrating surface. Alternatively, as shown in Figure 2, there is a method of directly bonding to the impact surface and using this bonded surface as a restraining material, and a method of laminating metal foil, plastic sheet, paper, non-woven fabric, etc. as a restraining material in advance to prevent vibrations. There are two ways to use it: by attaching it to a surface or an impact surface. In this case, choose whichever is more convenient for practical use, either exposing the film side of the viscoelastic film base material to the surface or having the restraining material on the surface. However, in order to improve the vibration damping properties, the sheet of the present invention may be
It is preferable to attach the upper and lower surfaces to the restraining material as shown in the figure. Furthermore, if a very soft contact surface is required, a flocked base material, a rubber sheet, or the like may be used as a restraining material or may be attached to the restraining material surface. Next, the viscoelastic substance will be explained. There are four types of viscoelastic bodies: a hot melt type, a type obtained by drying an aqueous or solvent-based diffusion polymer, a type obtained by subjecting a reactive liquid to a curing reaction, and a type obtained by dispersing an oil-swellable polymer powder in a plasticizer to obtain an elastomer. However, any type can be applied to achieve the present invention. Each of them has its own characteristics, but among them, the crosslinked viscoelastic material obtained by curing a reactive liquid material can respond to temperature changes over a wide temperature range, and in particular uses polymers that are reactive at room temperature. The viscoelastic material obtained by this process not only requires no energy for heating or drying during the manufacturing process, but also eliminates the need for equipment for recovering solvents during the drying process, and prevents corrosion of manufacturing equipment due to moisture. It is excellent in that it does not have any problems. Furthermore, among crosslinked viscoelastic bodies, substances that meet the following conditions are particularly desirable as viscoelastic bodies to be applied to the present invention. In other words, the viscoelastic body referred to in the present invention is a substance that is liquid at room temperature, and after reacting at room temperature, the hardened substance retains its shape even at an ambient temperature of 80°C and has a hardness of JIS -6301, which satisfies the condition of 80 or less on a Type A hardness tester at 20°C. Examples of reactive substances that can satisfy the above conditions include combinations of a liquid rubber having a functional group and a crosslinking agent as shown in the table.
Considering the ease of controlling curing rate, cost, and availability of room-temperature reactivity, these products have a hydroxyl group at the end and have a main chain of polybutadiene, hydrogenated polybutadiene, or polybutadiene-nitrile. , polybutadiene-styrene, isoprene, etc., polyether polyol, polyester polyol, urethane acrylic polyol,
It is desirable to use aniline derivative polyols or the like alone or in combination. Further, as the curing agent for the above-mentioned reactive substance, an isocyanate-based curing agent is suitable, and it is necessary that each molecule has two or more isocyanate groups. Specific examples include toluylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and prepolymers having isocyanate groups at both ends, which can be used alone or in combination.

[Table] Also, isocyanate curing agents can be used in combination with plasticizers due to problems such as blending ratio and/or viscosity, but the plasticizers must be dehydrated and do not react with isocyanate groups. things are necessary. Although it is possible to obtain a crosslinked viscoelastic material that satisfies the present invention by combining only the essential components for the room temperature reaction described above, various additives may be added in order to improve cost, workability, and physical properties. As a result, a wide variety of stable crosslinked viscoelastic substances can be obtained. Examples of additives include plasticizers, fillers, bituminous substances, tackifier resins, anti-aging agents, anti-mold agents, flame retardants, catalysts, surfactants, coupling agents, foaming agents such as water, and antifoaming agents. It will be done. The plasticizer is blended for the purpose of adjusting viscosity, adjusting workability, adjusting the physical properties of the crosslinked viscoelastic material, imparting flame retardance, and the like. Specific examples of plasticizers include naphthenic oils, paraffinic oils, aromatic oils, castor oil, cottonseed oil, pine oil, tall oil, phthalic acid derivatives, maleic acid derivatives, and liquid rubbers without functional groups. Or they can be used in combination. Furthermore, when flame retardancy is required, halogen compound-based or phosphorus compound-based plasticizers can be used alone or in combination. Examples of bituminous materials include straight asphalt, blown asphalt, and tar, which may be modified in advance with a tackifying resin, plasticizer, etc. in order to obtain a desired crosslinked viscoelastic material. Tackifier resins include natural resins, rosins, modified rosins, derivatives of rosins and modified rosins, polyterpene resins, modified terpenes, aliphatic hydrocarbon resins, cyclopentadiene resins, aromatic petroleum resins, phenolic resins, Alkylphenol-acetylene resin, xylene resin, coumaron-indene resin, vinyltoluene-α-methylstyrene copolymer, etc. can be used alone or in combination. Fillers are effective in improving vibration damping properties, sound insulation properties, and flame retardancy, and are used to adjust the blending ratio of main ingredient/curing agent, adjust viscosity, and reduce compounding costs. Those commonly used in paints are used. As a specific example,
Scale-like inorganic powders such as mica, graphite, vermiculite, talc, clay, ferrite, metal powder, barium sulfate, high density fillers such as lithopone, calcium carbonate, finely divided silica, carbon, magnesium carbonate, aluminum hydroxide, General-purpose fillers such as asbestos can be used alone or in combination. or,
Antimony trioxide, borax, etc. can be used for flame retardant purposes. Other additives include anti-aging agents, catalysts, pigments, surfactants, coupling agents, antifungal agents, etc., and these can be added as necessary. As mentioned above, the viscoelastic body has been described, but the hardness of the viscoelastic body has a great effect on compressive stress, impact relaxation force, and restorability, so it is necessary to select the above-mentioned materials depending on the purpose and use. Next, the constituent members of the impact cushioning sheet will be explained. The air-filled film base material is a general-purpose product that has been conventionally used as a packaging material. Convex portion: Concave portion = 2:
It is desirable that the ratio is 8 to 8:2, convex part: concave part =
When the convex portion is smaller than 2:8, the cost of raw materials increases and the restorability tends to deteriorate. On the other hand, if the convex portion is larger than the convex portion:concave portion ratio of 8:2, the raw material cost will be reduced, but the risk of destruction of the air chamber will increase, which is not preferable. Also, the thickness of the film that makes up the air sealing part is 20~
Approximately 100μ is desirable. Further, the height of the convex portion is preferably 6 mm or less, and a more preferable range is 2 mm to 4 mm. Further, the volume of air per convex portion is desirably 10 c.c. or less, and a more preferable range is 0.3 to 5 c.c.
Further, the crosslinked viscoelastic material to be filled may be in a state where it is filled and coated on the convex portions, but in consideration of cost, it is better to have a thickness of 1 mm or less. On the other hand, if the filling height is less than 3/4 of the height of the convex part, it will not adhere to the base material unless it is compressed by a considerable amount from the beginning, so the restraining effect will not be produced, and the thin film of the convex part will be damaged. It becomes easier. In addition, the materials that make up the film include polyethylene, polypropylene, nylon, polyester,
Films such as vinylidene chloride can be used, and among them, polyethylene and polypropylene have the advantage of being easily available as general-purpose products, and vinylidene chloride is a preferable material because it has excellent gas permeation resistance. Further, the shape of the gas-filled convex portion can be any shape such as a columnar shape, a prismatic shape, a semicircular shape, or an elliptical shape. Furthermore, as shown in Japanese Patent Application Laid-Open No. 60-105530, if a conductive air cushioning sheet is used, it can be applied as a conductive shock cushioning sheet, and this can be attached to a vibrating surface or a shock receiving surface. By doing so, it can be applied as an anti-static vibration damping material, and if metal foil is used as a restraining material, it can also be developed as an electromagnetic wave shielding material that also has vibration damping properties. Specific examples of restraining materials include metal sheets such as iron, copper, aluminum, stainless steel, brass, galvanized iron, lead, etc., polyester, vinyl chloride, polyethylene,
Plastic film sheets made of polypropylene, nylon, vinylidene chloride, ethylene-vinyl acetate copolymer, vulcanized rubber plates, non-vulcanized rubber plates,
Paper such as cardboard, compressed paper, felt paper, and split cloth, nylon, polyester, polypropylene,
Nonwoven fabrics using polyethylene, polyurethane, glass fiber, etc., natural fibers such as cotton, hemp, etc., and/or nylon, urethane, polypropylene, acrylic,
Synthetic fibers such as polyester, polyamide, polyimide, etc., wood-based binding materials include veneer, plywood, cork board, particle board, etc., and inorganic binding materials include wood chip cement board, fiber board, pulp cement board, etc. , wood wool cement board, flexible board, soft flexible board, large flat board, asbestos cement board, asbestos cement perlite board, asbestos cement calcium silicate board, plaster board, etc. The above-mentioned restraining material can be used regardless of whether or not it has a decorative finish and whether or not it has holes, but it is preferable that it be thin in consideration of reducing the total thickness of the constituent members. In addition, it is preferable to use a material with a high Young's modulus and a length that can be achieved if there are no restrictions on the use. Next, the present invention will be explained with reference to Examples and Comparative Examples. In Example 1, the viscoelastic body used in the present invention was made by curing reaction at room temperature with a main ingredient consisting of hydroxyl-terminated polybutadiene, asphalt, and a plasticizer, and a curing agent having two or more isocyanate groups per molecule. This shows good compression properties and impact resistance. It also shows sufficient performance even when applied to wooden finished floors. Example 2 shows the case where the viscoelastic body used in the present invention is a crosslinked viscoelastic body containing urethane as a basic component, and shows good compression properties and impact resistance, and can be used satisfactorily even at high temperatures. It shows.
It also shows sufficient performance even when applied to wooden finished floors. Example 3 shows the case where the viscoelastic body used in the present invention is a crosslinked viscoelastic body made of an emulsion-based viscoelastic body, and exhibits good compression properties and impact resistance. It also shows sufficient performance even when applied to wooden finished floors. Example 4 shows a case where the viscoelastic body used in the present invention has a styrene-isoprene-styrene copolymer as a basic polymer and is not crosslinked. In this case, although the shape retention at 80°C is slightly inferior, it can be used satisfactorily in applications where it is not used in a heated state, and it exhibits sufficient compression characteristics and impact resistance. Comparative Example 1 shows the case of a single film base material without a viscoelastic substance and having an uneven surface. In this case, the impact resistance will be extremely low, and the recovery performance will also be poor.
The purpose of the present invention cannot be achieved. Comparative Example 2 is a case where the volume ratio of the convex part to the concave part of the base film is 1:9, and the restorability is slightly inferior.
This increases the viscoelastic body ratio and increases the material cost, which is not preferable for achieving the object of the present invention. Comparative Example 3 is a case where the volume ratio of the convex part to the concave part of the base film is 9:1, and the restorability is poor, the impact resistance is poor, and the air chamber in the convex part of the film base material is damaged. Not recommended due to high risk.

【table】

[Table] The following products in Examples and Comparative Examples were used. *1 Hydroxyl group-terminated liquid polybutadiene...manufactured by Arco Chemical (USA), product name Poly Bd R-
45HT *2 Polyether polyol...Daiichi Kogyo Seiyaku Co., Ltd.
Manufacturer Product name Polyhardener D-350 *3 Acrylic emulsion...Chuo Rika Kogyo Co., Ltd.
Product name Ricabond PS-8000A *4 Rubber/asphalt emulsion...manufactured by Nippon Latex Kako Co., Ltd. Product name Harcoat*5 Styrene-isoprene-styrene copolymer...Ciel Chemical Co., Ltd. Product name Kraton 1107 *6 Recycled butyl rubber...Hayakawa Manufactured by Rubber Co., Ltd. Product name
Low Mooney recycled butyl *7 Plasticizer A...manufactured by Idemitsu Petrochemical Co., Ltd. Product name Diana Process Oil AH-16 *8 Plasticizer B...manufactured by Tokyo Jushi Kogyo Co., Ltd. Product name U
-Rex 180EF *9 Tackifying resin a...manufactured by Yasushi Oil Co., Ltd. Product name
YS range A-800 *10 Tackifying resin b...manufactured by Arakawa Chemical Co., Ltd. Product name
Alcon P-100 *11 Catalyst...Nippon Kagaku Sangyo Co., Ltd. Product name 28% Tin octylate*12 Solvent...Toluene*13 Isocyanate prepolymer...Polyflex MH manufactured by Daiichi Kogyo Seiyaku Co., Ltd. *14 Aziridine compound...Diphenylmethane-bis -4・4'-N・N'-diethylene urea Test method 1 A viscoelastic substrate was prepared according to the formulation shown in the examples and comparative examples, and a specified curing agent was mixed or dried and solidified. A film base material having the indicated volume of convex portions and concave portions was filled with the mixture to obtain a film with a viscoelastic body. 2 The base of the viscoelastic body obtained in the same manner as in Section 1 was
It was poured into a mold with dimensions of thickness x 120 mm width x 100 mm length to prepare a sample for hardness measurement. After curing for 7 days at room temperature and 7 days in an atmosphere at 50°C, hardness was measured at 20°C according to JIS-K-6301. 3 Shape retention at 80℃ Same as hardness measurement in Section 2, 30mm height x
Prepare a sample adjusted to a size of 50φ, apply release paper to the elastic surface, apply a load of 500g, and heat at 80℃.
After being allowed to stand for 24 hours, the sample was unloaded and allowed to stand at room temperature, and the degree of deformation after 4 hours was visually determined. Those with sharp edges and little deformation are marked with ○, those with no sharp edges,
Large deformations are indicated by an x mark. 4 Floor impact sound measurement To measure floor impact sound, attach the sample prepared in Section 1 to a 150 mm thick RC slab, and then
A 5.5mm thick decorative plywood board was pasted and the light impact sound was measured using a tapping machine. Measurement method is JIS
-A-1418, the method shown in Fig. 7 was adopted.
The results are shown in terms of floor impact sound insulation grade according to JIS-A-1419. 5 Restorability A 4 mm thick viscoelastic film obtained in Section 1 was prepared and cut into 4 mm x 50 mm width x 50 mm length.
Release paper was placed on the top and bottom, and the material was compressed to 50% using a compression tester at a compression speed of 2 mm/min, held for 30 minutes, unloaded, and restorability was checked after 10 minutes.
Those that showed a restorability of 95% or more were marked with an ○, those that showed a restorability of 90% or more were marked with a △, and those that showed a restorability of 90% or less were marked with an x. 6 Compression properties The relationship between compressive stress and displacement of the air-filled uneven film alone and the film with a viscoelastic body was determined using a compression tester at a compression speed of 2 mm/min.
The displacement and compressive stress were read from the chart obtained and shown in a graph. 7 Impact resistance The laminate of the 4 mm thick viscoelastic film obtained in Section 1 and 3 mm thick plywood was cut into a size of 30 mm x 30 mm, and subjected to an impact deformation test specified in Method B of JIS-K-5400. The impact conditions under which the air chamber would be destroyed were determined using a device. Explanation of the graph shown in FIG. 8: The graph shows the compression characteristics with and without a viscoelastic body. In other words, when comparing the compressive properties of the air-filled film base material with and without a viscoelastic body, almost no compressive load is required in the range where the displacement is smaller than that of the film itself, but in order to give a large displacement, a large compressive strength is required. This indicates that it is necessary to add That is, it can be said that it has ideal compression characteristics as an impact cushioning sheet. As mentioned above, the impact cushioning sheet of the present invention utilizes the compression characteristics of the enclosed air and the compression characteristics of the viscoelastic body, and further increases the restraint area due to the complex shape, thereby achieving more efficient impact cushioning and vibration damping performance. I can make it work well. In addition, by using a film with convex air chambers, the viscoelastic material used as raw material can be saved, making it possible to reduce costs.It is also a shock-absorbing sheet with a wide range of applications, as it also has a heat insulating effect due to the air layer. be.

[Brief explanation of the drawing]

FIG. 1 shows a cross section of an embodiment of the present invention, in which a plastic film whose recesses are filled with a viscoelastic material is adhered to the impact surface. Second
The figure shows a cross section of an embodiment of the present invention, in which a restraining material is bonded with an adhesive to a viscoelastic body filled in a concave portion of a plastic sheet having a convex air chamber. FIG. 3 shows a cross section of an embodiment of the present invention, in which a plastic film filled with a viscoelastic material over the entire surface of the recess is adhered to the impact surface. FIG. 4 shows a cross section of an embodiment of the present invention, in which a restraining material is bonded to the top and bottom of a plastic film whose recesses are filled with a viscoelastic material. FIGS. 5 and 6 each show a cross section of an embodiment of the present invention, and are examples in which the convex air chamber has a semicircular shape and a conical shape. FIG. 7 is a diagram showing an apparatus for measuring floor impact noise according to the present invention. Furthermore, the eighth
The figure is a diagram showing the influence of the presence or absence of a viscoelastic body according to the present invention on compression characteristics. 1... Plastic film having independent air chambers, 2... Viscoelastic body, 3... Impact surface, 4...
...Adhesive, 5...Restraint material, 6...Sound source chamber, 7...
Tapping machine, 8... Sample, 9... Floor slab, 10... Sound receiving room, 11... Microphone, 1
2... Precision sound level meter, 13... Frequency analyzer, 14
...Level recorder.

Claims (1)

[Scope of Claims] 1 Consisting of a structure in which concave portions of a film base material in which convex portions filled with air and concave portions consisting only of film are arranged alternately, and/or the entire surface thereof are filled with a viscoelastic substance, The volume ratio of the air volume of the air-filled convex part to the viscoelastic body filled in the film-only concave part is convex part: concave part = 2:8 to 8:2, and the height of the convex part is A shock-absorbing sheet characterized by having a diameter of 2 to 10 mm. 2. The viscoelastic material filling the recesses and/or the entire surface of the film base material, in which the convex portions filled with air and the recesses containing only the film are arranged alternately, performs a curing reaction, and after the curing reaction, The material retains its shape even when heated to 80℃, and its hardness is JIS at 20℃.
- The impact cushioning sheet according to claim 1, which has a hardness of 80 or less on a type A hardness tester. 3. The viscoelastic material filling the recesses and/or the entire surface of the film base material, in which the convex portions containing air and the recesses containing only the film are arranged alternately, contains a telechelic polymer having a hydroxyl group at the end. It is a crosslinked viscoelastic body obtained by subjecting a main ingredient as a basic component and a curing agent having two or more isocyanate groups per molecule to a curing reaction at room temperature. The impact cushioning sheet according to any of Item 2. 4. The crosslinked viscoelastic material filled in the concave portions of the film base material, in which convex portions containing air and concave portions containing only the film are arranged alternately, and/or the entire surface thereof, is made of hydroxyl-terminated liquid polybutadiene, asphalt, and plastic. Claim 1, characterized in that it is a crosslinked viscoelastic body obtained by causing a curing reaction at room temperature between a main ingredient having a curing agent as a basic component and a curing agent having two or more isocyanate groups per molecule. or third
Shock-absorbing sheet as described in any of paragraphs.