JPH0448099B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a method for manufacturing a vibration damping plate, which has excellent vibration damping and soundproofing performance, and particularly blocks impact noise caused by heavy impact sources, that is, low frequency sound sources. The present invention relates to a method of manufacturing a damping plate with improved performance. (Prior Art) In recent years, importance has been placed on sound insulation, prevention of dew condensation, heat insulation, prevention of pests, etc. from the perspective of livability in houses. Regarding sound insulation measures, due to technical difficulties, measures to improve the performance of blocking impact noise are attracting attention. Furthermore, in recent years, carpets,
Pests such as mites can easily breed in tatami mats, so wooden flooring materials are being reconsidered. However, the biggest drawback of wooden floors is that it is extremely difficult to block out impact noises caused by the sound of slippers and the sounds of children jumping. These impact noises are a type of noise that makes people feel uncomfortable, and it is known that the structure of the floorboards has a large effect because the noise is generated by the propagation of solid vibrations. As an impact source for evaluating the sound insulation performance of floor impact sound, the ``Method for measuring floor impact sound level in building sites JIS-A-1418'' uses impulse sources that consider walking in high-heeled shoes and falling knives. It defines a small lightweight impact source and a heavy impact source with a large impulse, which is considered to be the sound of falling fatigue and the sound of running around. Sound insulation performance due to light impact sources can be relatively easily improved by using floor finishing materials such as tatami floors or carpets on the upper floors, or by adding ceilings on the lower floors, but sound insulation performance due to heavy impact sources has a low frequency. Therefore, the usual method is to increase the thickness of the floorboard. (Problems to be Solved by the Invention) Increasing the thickness of the floorboards increases the rigidity and improves the sound insulation performance against weight impact sources, but the increase in the weight of the floorboards causes damage to the building structure itself such as columns and beams that support it. This results in reinforcement, a decrease in the space under the floor, an increase in the height of the eaves of the house, and a compression of the living space, which increases the disadvantages including the construction cost. In addition to improving rigidity by increasing the thickness of the floorboard, adding high vibration damping performance to the floorboard and increasing the loss of vibration energy within the floorboard should improve the ability to block floor impact noise. However, the main drawbacks are the need to exhibit sound insulation effects in the low frequency range, and the increased weight.
The technical conditions become extremely difficult when considering conditions such as the need to keep reinforcement of the building structure itself such as beams to a level that is not necessary, and the fact that it can be applied to existing houses as well. Conventionally, as vibration damping materials, there are those in which a sheet-type material is adhered to a structural member, or a damping material is applied or sprayed. However, in these non-restrictive types, the vibration damping effect will be reduced unless the thickness is two to several times the substrate thickness, and if the thickness is made sufficient, the cost will be high. On the other hand, as a means of imparting high vibration damping performance to buildings and other structures themselves, restraint-type vibration damping steel plates in which a viscoelastic substance is sandwiched between steel plates are known to have extremely high vibration damping performance. . Examples of viscoelastic materials include plastics made of resins such as vinyl acetate, vinyl chloride, and acrylic, as well as plasticizers and pigments, as disclosed in Japanese Patent Publication No. 39-12451 and Japanese Patent Publication No. 49-34703. Rubber-based viscoelastic substances made of polyisobutylene, polybutene, pigments, etc. are well known, but because these viscoelastic substances are hot-melt types that are melted and adhered to structural members, they are often used at construction sites, Or, even in the case of factory production,
It must be melted and applied at a temperature of 100°C or higher, and when applied to wood boards, problems such as blistering are likely to occur due to the influence of moisture from the wood boards, and the heat capacity is large, making it expensive. This is undesirable because it causes In addition, as a conventional method, as described in JP-A-55-90735, a urethane elastomer is bonded to a rigid plate-like body at the same time by integral foaming, and a notch is formed in the part of the urethane elastomer material that is in contact with the bottom surface of the base. However, foams are susceptible to permanent compressive strain, and even if they have a high vibration-preventing effect at the beginning of manufacture, their function gradually deteriorates, and the drawback is that long-term vibration-preventing effects cannot be guaranteed. . To this end, we use a relatively hard urethane elastomer that has many hard segments by increasing the number of hard segments using a chain extender during the manufacturing process of the urethane elastomer, and we also create a notch on the bonding surface with the substrate to increase the spring constant. However, there is a drawback that the vibration-preventing effect of the foam cannot be prevented from deteriorating over time. (Means for Solving the Problems) The present invention is designed to solve the problem of floor impact sound levels that have been lower than the conventional floor impact sound levels, especially in recent years when there has been an increasing demand for wooden materials instead of wall paper, carpets, and tatami mats due to problems with pests such as mites. In order to alleviate the impact noise of wood materials, which has been considered to be technically extremely difficult, and to achieve L-55 with wood materials, we have developed detailed information to solve the traditional requests and technical difficulties. The present invention was made as a result of many experiments, and the present invention consists of a liquid rubber having at least an end of hydroxyl groups and an isocyanate curing agent, which are mixed at a viscosity of 200,000 cps or less, and then Non-foaming viscoelastic material A, which is an elastomer obtained by crosslinking reaction at a reaction temperature of ℃ to 80℃, and in which the crosslinking reaction product does not flow under temperature conditions of 150℃ or less
A method for producing a vibration damping plate characterized in that a plurality of layers are applied to a wood-based and/or inorganic-based board material or a composite board B to form a restraint type A and B multilayer structure, and the weight increase is small. To provide a vibration damping plate having excellent vibration damping performance and excellent impact sound blocking performance. Next, the constituent materials of the present invention will be explained. Viscoelastic substance A consists of a liquid polymer with terminal hydroxyl groups and an isocyanate curing agent as essential components, which are mixed together at a viscosity of 200,000 cps or less, and then mixed at a reaction temperature of 0°C to 80°C. It is an elastomer obtained by crosslinking reaction, and the crosslinking reaction product is a non-foaming viscoelastic material that does not flow under temperature conditions of 150°C or lower. More specifically, hydroxyl-terminated liquid polymers include liquid rubber polyols whose main chain is polybutadiene, hydrogenated polybutadiene, polybutadiene-nitrile, polybutadiene-styrene, chloroprene, isoprene, etc., polyether polyols, polyester polyols, urethane acrylic polyols. These can be used alone or in combination. Examples of the isocyanate curing agent include toluylene diisocyanate, isophorone diisocyanate, prepolymers having isocyanate groups at the ends, and block products thereof, which can be used alone or in combination.
The isocyanate curing agent has its blending ratio and
Due to problems such as viscosity, it can be used in combination with a plasticizer, but the plasticizer must be dehydrated and must not react with the isocyanate compound. Although it is possible to obtain a viscoelastic material that satisfies the present invention by combining only the above essential components,
From the viewpoint of cost, workability, and physical properties, a wide variety of stable viscoelastic substances can be obtained by adding various additives. As additives, mention may be made of plasticizers, bituminous substances, fillers, etc. Next, specific examples thereof will be shown. Plasticizers are blended for the purposes of adjusting viscosity and workability, controlling the physical properties of viscoelastic bodies, and imparting flame retardancy. Specific examples of plasticizers include naphthenic acid oil,
Paraffin oil, aromatic oil,
There are castor oil, cottonseed oil, pine oil, tall oil, phthalic acid derivatives, isophthalic acid derivatives, adipic acid derivatives, maleic acid derivatives, and those that do not contain the tubular functional group of liquid rubber, and they can be used alone or in combination. . Bituminous materials include straight asphalt, blown asphalt, tar, etc., and in order to obtain a desired viscoelastic body, they can be used after being modified with a tackifying resin, a petroleum softener, etc. Fillers affect vibration damping properties, sound insulation properties, and flame retardancy, and are used to adjust the blending ratio of the main ingredient/curing agent, adjust viscosity, and reduce the cost of blending. Those used in paints can be used. Specific examples include mica, graphite,
Scale-like inorganic powders such as vermiculite, clay, and talc, high-density fillers such as ferrite, metal powder, barium sulfate, and lithopone, and general-purpose materials such as calcium carbonate, powdered silica, carbon, magnesium carbonate, aluminum hydroxide, and asbestos. Fillers and the like can also be used alone or in combination. Moreover, antimony trioxide and borax can also be used for the purpose of flame retardation. As other additives, various anti-aging agents, catalysts, pigments, surfactants, insect repellents, anti-mold agents, and coupling agents can be added. The viscoelastic substance A blended as described above has a viscosity of 200,000 CPS or less during two-component mixing operation, and the crosslinking reaction product does not flow under temperature conditions of 150°C or less. It is desired that the mechanical loss rate be large in the low frequency range. Further, this viscoelastic substance A undergoes a crosslinking reaction using an isocyanate curing agent, and the crosslinking density can be controlled by adjusting the reaction molar ratio by adjusting the amount of the isocyanate curing agent added. the result,
Although very soft viscoelastic materials to hard viscoelastic materials can be obtained, the reaction molar ratio suitable for the present invention is between 0.5 mol and 1.5 mol NCO/OH. If the reaction molar ratio is less than 0.5 mol NCO/OH, the isocyanate curing agent is insufficient, and unreacted hydroxyl group-terminated polymer becomes excessive, leading to flow phenomena at high temperatures and poor rubber elasticity at low temperatures. This results in drawbacks such as poor vibration absorption temperature characteristics and increased compression set. Furthermore, in terms of construction, there is an increased risk of curing failure. Conversely, when the reaction molar ratio is 1.5 moles NCO/OH or more, the isocyanate curing agent becomes excessive, which tends to impair rubber elasticity and damping properties in the service temperature range and low frequency range. In addition, in terms of construction, a foaming phenomenon is likely to occur due to the generation of carbon dioxide gas due to the reaction of excess isocyanate-based curing agent with trace amounts of moisture, etc., which is undesirable since there is a risk of adversely affecting the durability of the viscoelastic material. The required amount of isocyanate curing agent (reaction molar ratio) per 100 parts by weight of hydroxyl terminated liquid rubber
1.0NCO/OH) is calculated as follows. Required amount of curing agent=weight of hydroxyl-terminated liquid rubber (100) x hydroxyl group content (wt%)/isocyanate group content (wt%) x NCO/OH where NCO/OH = 42/17 = 2.47. The hydroxyl group content refers to the weight percentage of hydroxyl groups in the hydroxyl group-terminated liquid rubber. The isocyanate group content refers to the weight percentage of isocyanate groups in the isocyanate curing agent. Next, regarding the crosslinking reaction conditions, the viscoelastic substance applied to the present invention consists of a main ingredient containing a hydroxyl-terminated liquid rubber that is liquid at room temperature or when heated, and an isocyanate curing agent that is liquid at room temperature. It is a substance obtained by mixing and performing a crosslinking reaction, and the conditions for performing the crosslinking reaction are as follows:
Temperature and time factors greatly affect the crosslinking reaction rate;
The crosslinking curing time required to reach non-fluid solidification becomes longer as the temperature decreases, and preferably the crosslinking reaction temperature is in the temperature range of 0°C to 80°C. Next, wood-based and/or inorganic-based board material or composite board material B will be explained. Specific examples of wood-based board materials include various wood veneers, such as plywood, decorative plywood, parquet board, cork board, lauan board, and cedar board. Specific examples of inorganic boards include asbestos boards, wood wool cement boards, silica boards, ALC boards, PC boards, and concrete boards. Composite board materials include not only the above-mentioned wood board materials and/or inorganic board materials and combinations thereof, but also vulcanized rubber sheets, non-vulcanized rubber sheets, plastic sheets including vinyl chloride, various foams including polyethylene, 1 glass fiber, felt, etc.
It refers to a type or a combination of two or more types laminated together, and these are also effective for adjusting the unevenness of the vibration damping plate mounting base material. In addition, the wood-based and/or inorganic board material or composite board material B does not necessarily have to be a flat board, and may be a perforated board, a grooved board, a corrugated board, etc. depending on the intended use. good. Next, the combination of the wood-based and/or inorganic board material or the composite board B and the viscoelastic substance A may be any combination, and the viscoelastic material A may have two or more layers depending on the combination with the board material B. It may become. In addition, the thickness of the viscoelastic material A is 0.5 mm per layer.
A thickness of 10.0 mm is desirable; if it is less than 0.5 mm, the impact isolation ability is poor, and if it is more than 10.0 mm, it is inappropriate from a cost perspective. The plate material B may be any material that is commonly used in terms of performance and economy and is easy to handle, as long as it has a thickness that provides sufficient rigidity. The damping plate configured as described above can of course be applied not only as a flooring material but also as a ceiling material and a wall material. Next, embodiments of the damping plate of the present invention will be shown, but the present invention is not limited thereto in any way. First, one aspect of the production of viscoelastic material A will be described. Pour the reactive liquid rubber into a stirring container, add the heated and melted asphalt, tackifier resin, and plasticizer, mix to make a sufficiently uniform solution, and then add fillers, anti-aging agents, catalysts, etc. Add as appropriate,
For example, the main ingredient of the viscoelastic substance is obtained as a sufficiently uniform solution using a mixing and dispersing machine such as an ink roll. Next, an isocyanate curing agent was added to the base material obtained in the above method, and the mixture was sufficiently mixed, and then applied onto a wood board to cause a crosslinking reaction, thereby obtaining a vibration damping plate of the present invention. Next, Table 1 shows an example of the crosslinking reaction of the viscoelastic material A used in the present invention in terms of the relationship between the liquid temperature and the time required for solidification. The viscoelastic material A used in the present invention undergoes a crosslinking reaction even at a low temperature of 0°C or lower to a high temperature of 80°C or higher, but the time required for the crosslinking reaction at a low temperature of 0°C or lower is too long. In addition, in the case of high temperatures of 80°C or higher, problems such as blistering due to water vapor generated from wood-based and/or inorganic board materials or composite board material B are likely to occur. 80
It is desirable to carry out the crosslinking reaction in the temperature range of °C. Next, Table 2 shows blending examples of the viscoelastic material A used in the present invention. The formulation examples shown in Table 2 are all viscoelastic substances that can be applied to the present invention, but each has the following characteristics. Formulation Example 1 has characteristics such as low viscosity, excellent workability, and almost no difference in impact insulation properties due to temperature changes. Formulation Example 2 is a type in which the weight ratio of the main agent and curing agent is 100:8 when crosslinking the viscoelastic substance, and the mixing and stirring operation is improved. Formulation example 3 is a combination example in which the cost aspect of the viscoelastic substance is particularly important. This type has the characteristics of improved workability and fast crosslinking reaction rate by heating, and is suitable for factory line production.

【table】

【table】

[Table] Next, the test method is described. A specimen with the configuration shown in Table 3 was used, and JIS-A
The floor impact sound level was measured in accordance with the ``Method for measuring floor impact sound level at building sites'' described in 1418. Incidentally, Fig. 5 shows a schematic diagram of the test equipment. Table 4 shows the measurement results and the evaluation based on the "sound insulation grade for evaluation of floor impact noise." Next, a viscoelastic substance A and a wood-based material, which have the hydroxyl-terminated liquid rubber and the isocyanate curing agent as essential components applied to the present invention, and in which the crosslinking reaction product does not flow under temperature conditions of 150°C or lower, and/or Tables 3 and 4 show the structure and damping effect of the inorganic plate material or composite plate material B. Example 1 is an example in which a wooden floor material is used as a board material B, and a viscoelastic material A is laminated thereon. Example 2 is an example in which lauan plywood and a polyethylene foam sheet were laminated on Example 1. Example 3 is an example in which an asbestos board and a polyethylene foam sheet were further laminated on Example 1. Comparative Example 1 is an example in which a vulcanized rubber plate was used instead of the viscoelastic material A. Comparative Example 2 is an example in which the same plate material B used in Examples 1 to 3 is used alone. Comparative Example 3 is an example in which the asbestos board used in Example 3 was used alone. Comparative Example 4 is an example in which the thickness of the viscoelastic material A is 0.5 mm or less. From the results shown in Table 4, Example 1 is a damping plate made by laminating viscoelastic material A to a thickness of 5 mm on wood board B, and achieves a sound insulation grade of L-55. In Example 2, a viscoelastic substance A is placed between wood-based board B.
Laminated with a thickness of 3 mm, and then a polyethylene sheet,
Or, it is a vibration damping plate made of laminated rubber sheets, achieving a sound insulation grade of L-55. Example 3 is a vibration damping plate made by laminating a viscoelastic substance A between a wooden board B and an inorganic board B, and further laminating a polyethylene sheet or a rubber sheet, and has a sound insulation grade of L-55. Achieved. Comparative Example 1 is a damping board made by laminating wood-based flooring material B and a vulcanized rubber board with a chloroprene adhesive, but since the viscoelastic material A is not laminated, the manufacturing method of the damping board of the present invention is not applicable. does not apply. Comparative Example 2 shows the case where the wooden board B used as the surface layer in Examples 1 to 3 was used alone, and does not correspond to the present invention. Comparative Example 3 shows the case where the inorganic plate material B used in Example 3 was used alone, and does not correspond to the present invention. In Comparative Example 4, the thickness of the viscoelastic material A of Example 1 was
The thickness is 0.4 mm, which is outside the thickness condition of the viscoelastic material A of the present invention. From the above, Examples 1 to 3 all achieved the sound insulation grade L-55, and a significant improvement was achieved by applying the viscoelastic material A to the damping plate. Although the sound insulation performance of Comparative Example 4 is not sufficient, it is considerably improved, and it can be seen that the impact sound insulation performance of the viscoelastic material is high. As mentioned above, the damping material obtained by the present invention was able to achieve a sound insulation grade of L-55 in wood-based board materials, which was not possible with the prior art. The vibration damping material of the present invention is not limited to floors only, but can be applied to ceiling materials and wall materials, making it extremely effective in blocking impact noise and creating a comfortable living space. The contribution to society is significant.

【table】

[Table] Note: Thickness is shown in parentheses.

[Table] Depends

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional diagram showing the lamination of plate material B and viscoelastic substance A, and FIG. 2 is a cross-sectional diagram showing the lamination of plate material B and viscoelastic substance A. FIG. , or a sectional configuration diagram of a laminated rubber sheet, and FIG. 3 is a sectional configuration diagram of a laminated plate material B and a rubber sheet, or a foamed polyethylene sheet, a viscoelastic substance A, and glass wool, felt, or various foams. , FIG. 4 is a cross-sectional configuration diagram in which plate material B and viscoelastic material A are alternately laminated, and FIG. 5 is a schematic diagram of the experimental equipment. 1... Damping plate mounting base material, 2... Wooden board material or inorganic board material, 3... Viscoelastic substance, 4... Rubber sheet,
or foamed polyethylene sheet, 5...glass wool, or various foams, or felt.

Claims (1)

[Claims] 1. A liquid rubber having at least a hydroxyl group at the end;
An isocyanate curing agent is an essential component, and this is mixed at a viscosity of 200,000 cps or less, and this is heated from 0℃ to 80℃.
A non-foamed viscoelastic material A, which is an elastomer obtained by a crosslinking reaction at a reaction temperature of 150°C and in which the crosslinking reaction product does not flow under a temperature condition of 150°C or less, is used as a wood-based and/or inorganic board material, or Composite board material B
A method for manufacturing a vibration damping plate, characterized in that a plurality of layers are adhered to the plate to form a restraining type A and B multilayer structure. 2 Viscoelastic substance A has a viscosity of 200,000 yen during two-liquid mixing work.
cps or less and is a non-foamed elastomer obtained by crosslinking reaction at a low to medium-high crosslinking reaction temperature of 0°C to 80°C. Production method. 3 The thickness of the crosslinking reaction product of the viscoelastic substance is 0.5 mm ~
Claim 1 characterized in that the diameter is 10.0 mm.
Method of manufacturing the vibration damping plate described in Section 1. 4. The method for manufacturing a damping plate according to claim 1, wherein the viscoelastic substance A is obtained by blending an appropriate amount of one or more of a plasticizer, a bituminous agent, and a filler as an additive. . 5 Viscoelastic substance A is a patent claim obtained by blending appropriate amounts of any one or two or more of various anti-aging agents, catalysts, pigments, surfactants, insect repellents, fungicides, and coupling agents as additives. A method for manufacturing a damping plate according to item 1. 6. The reaction molar ratio between the liquid rubber having a hydroxyl group at the end and the isocyanate curing agent is 0.5 to 1.5 moles.
A method for manufacturing a damping plate according to claim 1, which is NCO/OH. 7 The required amount of isocyanate curing agent for 100 parts by weight of liquid rubber having a hydroxyl group at the end is calculated as follows: Required amount of curing agent = Weight of hydroxyl group-terminated liquid rubber (100) x Hydroxyl group content (wt%) / Isocyanate group content (wt%) )×NCO/OH where NCO/OH=42/17=2.47, the method for manufacturing a damping plate according to claim 1.