Vehicular floor silencer and method for manufacturing the same

Abstract

To provide a vehicular floor silencer light in weight, high in acoustic insulation, and high in comfort (hardness), and a method for manufacturing the same.SOLUTION: In a vehicular floor silencer 10 containing a polyurethane foam, the polyurethane foam is formed, in a mole, by a polyurethane foam raw material containing polyol, polyisocyanate, a catalyst, and a foaming agent. The polyol includes main polyol made of polyether polyol having molecular weight of 3000-12000 and an EO rate of 5-20% and sub polyol made of polyether polyol having molecular weight of 2000-7000 and an EO rate of 50-90%. The foaming agent is water.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a floor silencer for a vehicle and a method for manufacturing the same. [Background technology]

[0002] Conventionally, floor silencers (or sometimes floor spacers) placed on the floor panels of vehicles are made of polyurethane foam formed by molding, in which polyurethane foam raw materials containing polyol, polyisocyanate, catalyst, and blowing agent are injected into a mold and allowed to foam (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2013-86639 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional vehicle floor silencers are made of harder polyurethane foam to improve comfort when stepped on by passengers, but the harder polyurethane foam has the problem that solid-borne sound from the floor panel on which the vehicle floor silencer is placed is easily transmitted as vibration noise into the vehicle cabin.

[0005] In addition, vehicle floor silencers are required to be lightweight, and in order to achieve this, it is necessary to increase the amount of water used as a blowing agent in the polyurethane foam raw material.However, if the amount of water is increased, the ratio of polyisocyanate that reacts with the active hydrogen groups in the polyurethane foam raw material increases, and the polyurethane foam that is formed becomes harder, so increasing the amount of water to reduce weight is no longer sufficient to suppress solid-borne sound.

[0006] In addition, there is a method of lowering the isocyanate index as a method of lowering the hardness of polyurethane foam, but the sound insulation effect obtained is small by simply lowering the isocyanate index. The isocyanate index is a numerical value that expresses the equivalent ratio of the isocyanate group of the isocyanate to the active hydrogen group in the polyurethane foam raw material (e.g., the active hydrogen group contained in the hydroxyl group of polyols and the active hydrogen group of water as a blowing agent, etc.) in a percentage. In addition, if the isocyanate index is lowered to lower the hardness of the polyurethane foam, the vehicle floor silencer will sink more when stepped on, and the comfort of stepping on it will be worse.

[0007] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a vehicle floor silencer that is lightweight, has good sound insulation properties and provides a comfortable stepping feeling, and a method for manufacturing the same. [Means for solving the problem]

[0008] The invention of claim 1 relates to a vehicle floor silencer made of polyurethane foam, the polyurethane foam being molded in a mold from polyurethane foam raw materials including polyol, polyisocyanate, a catalyst, and a blowing agent, the polyol including a main polyol made of a polyether polyol having a molecular weight of 3000 to 12000 and an EO ratio of 5 to 20%, and a sub-polyol made of a polyether polyol having a molecular weight of 2000 to 7000 and an EO ratio of 50 to 90%, and the blowing agent being water.

[0009] The invention of claim 2 is the invention of claim 1, wherein the polyurethane foam has a density of 40 to 60 kg / m 3 It is characterized in that:

[0010] The invention of claim 3 is characterized in that in the first or second aspect, the 25% compression hardness is 30 to 200N.

[0011] The invention of claim 4 is characterized in that in any one of claims 1 to 3, the average transmission loss from 1 to 4 kHz measured based on JIS A1441-1:2007 is 60 to 65 dB.

[0012] The invention of claim 5 is characterized in that, in any one of claims 1 to 4, a hardness-enhancing material made of expanded polystyrene or expanded polypropylene or a polystyrene-polyolefin composite foam material is laminated to at least a portion of the polyurethane foam.

[0013] The invention of claim 6 relates to a method for producing a vehicle floor silencer made of polyurethane foam by injecting a polyurethane foam raw material containing a polyol, a polyisocyanate, a catalyst, and a blowing agent into a mold and foaming it, characterized in that the polyurethane foam raw material contains a polyol, a polyisocyanate, a catalyst, and a blowing agent, the polyol contains a main polyol made of a polyether polyol having a molecular weight of 3000 to 12000 and an EO ratio of 5 to 20%, and a sub polyol made of a polyether polyol having a molecular weight of 2000 to 7000 and an EO ratio of 50 to 90%, the blowing agent is water, and has an isocyanate index of 65 to 85.

[0014] The invention of claim 7 is characterized in that in claim 6, the sub-polyol is 2.5 to 10 parts by weight based on 100 parts by weight of the main polyol.

[0015] The invention of claim 8 relates to a method for manufacturing a vehicle floor silencer as described in claim 6 or 7, characterized in that a hardness-enhancing material made of expanded polystyrene or expanded polypropylene or a polystyrene-polyolefin composite foaming material is placed on the inner surface of the mold, and the polyurethane foam raw material is injected into the mold and foamed, thereby laminating the hardness-enhancing material on at least a portion of the polyurethane foam. Effect of the Invention

[0016] According to the present invention, the density is 40 to 60 kg / m 3 It is possible to obtain a vehicle floor silencer that has excellent lightness, comfort, and sound insulation, and has a 25% compression hardness of 30 to 200 N and an average transmission loss of 60 to 65 dB from 1 to 4 kHz measured based on JIS A1441-1:2007.

[0017] In addition, by laminating a hardness-increasing material made of expanded polystyrene, expanded polypropylene, or a polystyrene-polyolefin composite foam material to the area where hardness is desired to be increased, a vehicle floor silencer can be obtained in which the desired area is harder than other areas. [Brief description of the drawings]

[0018] [Figure 1] 1 is a cross-sectional view of a vehicle floor silencer according to a first embodiment. [Diagram 2] 3 is a cross-sectional view of a mold showing a manufacturing process of the vehicle floor silencer of the first embodiment. FIG. [Diagram 3] FIG. 6 is a cross-sectional view of a vehicle floor silencer according to a second embodiment. [Figure 4] 10 is a cross-sectional view of a mold showing a manufacturing process of the vehicle floor silencer of the second embodiment. FIG. [Diagram 5] 1 is a table showing the configurations and the measurement results of the physical properties and sound insulation properties of each of the examples and comparative examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the present invention will be described. A vehicle floor silencer 10 of the first embodiment shown in Fig. 1 is made of polyurethane foam 11 molded in a mold from polyurethane foam raw material containing polyol, polyisocyanate, a catalyst, and a blowing agent. The shape of polyurethane foam 11 is a planar shape and a three-dimensional (concave-convex) shape that corresponds to the floor panel of the vehicle on which it is placed.

[0020] The polyol includes a main polyol and a sub polyol. The main polyol has an ethylene oxide content (abbreviated as "EO ratio") of 5 to 20%, preferably 12 to 20%, and the sub polyol has an EO ratio of 50 to 90%, preferably 60 to 80%. The ratio of the main polyol and the sub polyol to the total polyol is 50 to 98% by mass for 100% by mass of the total polyol, and the sub polyol is less than 50% by mass, preferably 2 to 20% by mass, and is less than the main polyol. The main polyol is a polyether polyol having a molecular weight (number average molecular weight) of 3000 to 12000, more preferably 4000 to 7000, and an EO ratio (ethylene oxide content) of 5 to 20%, more preferably 12 to 20%. The EO ratio of the polyether polyol is the content of ethylene oxide units when the total amount of one raw material composition unit is 100% by weight. The number of functional groups of the main polyol is preferably 2 to 4. Examples of polyether polyols include polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, and sucrose, and polyether polyols in which alkylene oxides such as ethylene oxide and propylene oxide are added to the polyhydric alcohols. The main polyol is not limited to one type, and multiple types may be used in combination.

[0021] In the present invention, it is preferable that the main polyol does not contain a polymer polyol. When the main polyol contains a polymer polyol, sound insulation is reduced. The polymer polyol is obtained by polymerizing an ethylenically unsaturated compound in a polyether polyol.

[0022] The sub-polyol is a polyether polyol having a molecular weight of 2000 to 7000, more preferably 3000 to 5000, and an EO ratio of 50 to 90%, more preferably 60 to 80%. The number of functional groups of the sub-polyol is preferably 2 to 4. In the present invention, the sub-polyol acts as a cell opener (cell breaker) and improves the sound insulation of the polyurethane foam. The amount of the sub-polyol is preferably 2.5 to 10 parts by weight per 100 parts by weight of the main polyol. If the amount of the sub-polyol is too small, the sound insulation effect is reduced, and if the amount is too large, the hardness becomes soft and the comfort of stepping on the foam deteriorates. The sub-polyol is not limited to one type, and multiple types may be used in combination.

[0023] The catalyst may be a foaming catalyst or resinification catalyst known for polyurethane foams. The foaming catalyst is an amine-based catalyst that promotes the reaction between polyisocyanate and water to generate carbon dioxide gas, and affects the fluidity of the polyurethane foam during the reaction. The foaming catalyst is not limited, and examples thereof include triethylamine, dimethylaminoethoxyethanol, N,N,N'-trimethylaminoethyl-ethanolamine, N,N,N',N",N"-pentamethyldiethylenetriamine, bis(2-dimethylaminoethyl)ether, etc.

[0024] The resinification catalyst is an amine catalyst that promotes the urethane reaction (resinification reaction) between polyol and polyisocyanate. The resinification catalyst is not limited, and examples thereof include 1,2-dimethylimidazole, N·(N',N'-dimethylaminoethyl)-morpholine, tetramethylguanidine, dimethylaminoethanol, triethylenediamine, N-methyl-N'-(2-hydroxyethyl)-piperazine, N,N,N',N'-tetramethylpropane 1,3-diamine, N,N'-dimethylpiperazine, N,N,N',N'-tetramethylhexane-1,6-diamine, N,N,N',N",N"-pentamethyldipropylene-triamine, N-(2-hydroxyethyl)morpholine, ethylene glycol bis(3-dimethyl)-aminopropyl ether, N,N-dimethylcyclohexylamine, and N-methyl-N'-(2-dimethylamino)ethylpiperazine. The ratio of the foaming catalyst to the resinification catalyst is preferably foaming catalyst amount / resinification catalyst amount=3 / 100 to 3 / 100. In addition, other amine compounds or organometallic compounds may be used as co-catalysts together with the foaming catalyst and the resinification catalyst.

[0025] The foaming agent is preferably water. The amount of water used as the foaming agent is preferably 3 to 7 parts by weight, more preferably 5 to 6 parts by weight, per 100 parts by weight of the main polyol. If the amount of water is too small, the foaming ratio does not increase and the density becomes high, while if the amount of water is too large, the ratio of polyisocyanate that reacts with active hydrogen groups in the polyurethane foam raw material increases, and the polyurethane foam formed becomes hard, making it impossible to suppress solid-borne sound.

[0026] The polyisocyanate may be any of aromatic, alicyclic, and aliphatic isocyanates, and may be a bifunctional isocyanate having two isocyanate groups in one molecule, or a trifunctional or higher isocyanate having three or more isocyanate groups in one molecule, and these may be used alone or in combination.

[0027] For example, as a bifunctional isocyanate The following are examples of diisocyanates: 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate. Examples of the isocyanate include aromatic isocyanates such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and methylcyclohexane diisocyanate; and aliphatic isocyanates such as butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, and lysine diisocyanate.

[0028] Examples of tri- or higher functional isocyanates include 1-methylbenzene-2,4,6-triisocyanate, 1,3,5-trimethylbenzene-2,4,6-triisocyanate, biphenyl-2,4,4'-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, methyldiphenylmethane-4,6,4'-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2',5,5'tetraisocyanate, triphenylmethane-4,4',4"-triisocyanate, polymeric MDI, and the like. Other urethane prepolymers can also be used. The number of isocyanates is not limited to one, and may be one or more. For example, one type of aliphatic isocyanate and two types of aromatic isocyanate may be used, or two types of aromatic isocyanate and urethane prepolymer may be used, or three or more types of isocyanates may be used.

[0029] The isocyanate index is preferably 65 to 85, and more preferably 70 to 80. The isocyanate index is an index used in the field of polyurethanes, and is a numerical value that represents the equivalent ratio of isocyanate groups of isocyanate to active hydrogen groups in raw materials (for example, active hydrogen groups contained in hydroxyl groups of polyols and active hydrogen groups of water as a blowing agent, etc.) expressed as a percentage.

[0030] The polyurethane foam raw material may include foam stabilizers and additives as appropriate components. The foam stabilizer may be any foam stabilizer that is used in polyurethane foam, and may include silicone foam stabilizers, fluorine-containing compound foam stabilizers, and known surfactants. The amount of foam stabilizer is preferably 0 to 1.0 parts by weight per 100 parts by weight of the main polyol.

[0031] Examples of additives include crosslinking agents, pigments, fillers, flame retardants, antioxidants, and ultraviolet absorbers. Examples of crosslinking agents include glycerin, trimethylolpropane, 1,2,4-butanetriol, 2-methyl-2,3,4-butanetriol, diethanolamine, triethanolamine, and pentaerythritol, and one or more of these may be used in combination. The amount of the crosslinking agent is preferably 0 to 1.5 parts by weight based on 100 parts by weight of the main polyol.

[0032] Examples of the pigment include carbon black, titanium oxide, etc. Examples of the filler include graphite, alumina, melamine, etc.

[0033] Examples of the flame retardant include halogenated diphenyl ethers such as degabromdiphenyl ether and octabromdiphenyl ether; halogen compounds such as halogenated polycarbonates; inorganic compounds such as antimony trioxide, antimony tetraoxide, antimony pentoxide, sodium pyroantimonate, and aluminum hydroxide; triazine ring-containing compounds, metal hydroxides, phosphate flame retardants, condensed phosphate flame retardants, phosphate flame retardants, inorganic phosphorus flame retardants, dialkylphosphinates, silicone flame retardants, metal oxides, boric acid compounds, and expandable graphite.

[0034] Examples of the antioxidant include naphthylamines, diphenylamines, p-phenyldiamines, quinolines, hydroquinone derivatives, monophenols, thiobisphenols, hindered phenols, and phosphites.

[0035] Examples of the ultraviolet absorber include 2-hydroxybenzophenones such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, and 5,5'-methylenebis(2-hydroxy-4-methoxybenzophenone); 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole, and 2-(2'-hydroxy-3',5'- 2-(2'-hydroxyphenyl)benzotriazoles such as 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole, 2-(2'-hydroxy-3',5'-dicumylphenyl)benzotriazole, 2,2'-methylenebis(4-tert-octyl-6-(benzotriazolyl)phenol), 2-(2'-hydroxy-3'-tert-butyl-5'-carboxyphenyl)benzotriazole; phenyl Benzoates such as ricinate, resorcinol monobenzoate, 2,4-ditert-butylphenyl-3,5-ditert-butyl-4-hydroxybenzoate, 2,4-ditert-amylphenyl-3,5-ditert-butyl-4-hydroxybenzoate, hexadecyl-3,5-ditert-butyl-4-hydroxybenzoate; substituted oxanilides such as 2-ethyl-2'-ethoxyoxanilide, 2-ethoxy-4'-dodecyloxanilide; ethyl-α-cyano-β,β-diphenylacrylate, methyl cyanoacrylates such as aryl-2-cyano-3-methyl-3-(p-methoxyphenyl)acrylate; and triaryltriazines such as 2-(2-hydroxy-4-octoxyphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-s-triazine, 2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-s-triazine, and 2-(2-hydroxy-4-propoxy-5-methylphenyl)-4,6-bis(2,4-di-tert-butylphenyl)-s-triazine.

[0036] A manufacturing example of the vehicle floor silencer 10 will be shown. The vehicle floor silencer 10 can be produced by molding using a metal mold 20 shown in FIG. 2. The surface of the metal mold 20 is determined according to the shape required for the vehicle floor silencer 10. After a release agent is applied to the surface of the metal mold 20, polyurethane foam raw material 11a is mixed and injected into the metal mold 20, which is then closed to foam the polyurethane foam raw material 10a in the molding space between the surfaces of the lower mold 21 and the upper mold 33, thereby forming the polyurethane foam 11. Thereafter, the metal mold 20 is opened, and the vehicle floor silencer 10 made of the polyurethane foam 11 is demolded.

[0037] The injection of polyurethane foam raw material 10a into the mold is not limited to the open injection method in which mold 20 is opened, but may be a so-called closed injection method in which a raw material injection port is formed in part of mold 20 and the polyurethane foam raw material is injected into the mold through the raw material injection port while the mold is closed.

[0038] The thickness of the polyurethane foam 11 is preferably 2 to 50 mm. If the thickness is too thin, the sound insulation performance is reduced, and if the thickness is too thick, the interior space of the vehicle becomes narrow.

[0039] The density of polyurethane foam 11 (JIS K7222:2005) is 40 to 60 kg / m 3 It is preferable that the density of the polyurethane foam 11 is 40 to 60 kg / m 3 This makes it possible to improve the lightweight property of the vehicle floor silencer 10. In the first embodiment, the density of the polyurethane foam 11 corresponds to the overall density of the vehicle floor silencer 10.

[0040] The 25% compression hardness of the polyurethane foam 11 is preferably 30 to 200N, more preferably 30 to 70N. The compression hardness is measured based on ILD (Indentation Load Deflection), which is one of the load measurement methods. Specifically, a test piece having a surface of 200 mm×200 mm and a height of 20 mm is compressed at a speed of 50 mm / min by a circular plate (pressure piece) having a diameter of 80 mm. The value of the load (N) acting on the circular plate when the test piece becomes 25% of the height (20 mm) of the test piece before compression is the 25% compression hardness. By setting the 25% compression hardness of the polyurethane foam 11 within the above range, the vehicle floor silencer 11 is less likely to sink when stepped on by an occupant, and the stepping comfort is improved. In the first embodiment, the 25% compression hardness of the polyurethane foam 11 corresponds to the 25% compression hardness of the vehicle floor silencer 10.

[0041] The polyurethane foam 11 has an average transmission loss of 60 to 65 dB at 1 to 4 kHz (JIS A1441-1:2007). Since the polyurethane foam 11 has an average transmission loss of 60 to 65 dB at 1 to 4 kHz, the vehicle floor silencer 11 can reduce solid-borne sound from the floor panel, and has good sound insulation. In the first embodiment, the average transmission loss of the polyurethane foam 11 at 1 to 4 kHz corresponds to the average transmission loss of the vehicle floor silencer 10 at 1 to 4 kHz.

[0042] A vehicle floor silencer 30 according to a second embodiment will be described below with reference to Fig. 3. In the vehicle floor silencer 30 according to the second embodiment, a hardness increasing material 35 is laminated on at least a part of a polyurethane foam 31.

[0043] The polyurethane foam 31 has a similar structure to the polyurethane foam 11 in the first embodiment.

[0044] The hardness-increasing material 35 is laminated on the portion of the vehicle floor silencer 30 where increased hardness is required. The hardness-increasing material 35 is made of a foam harder than the polyurethane foam 31, and preferably has a hardness (JIS K6767:1999) of 100 to 500 kPa. Furthermore, the hardness-increasing material 35 is preferably lighter (has a lower density) than the polyurethane foam 31 so as not to impair the light weight of the vehicle floor silencer 30, and preferably has a density (JIS K6767:1999) of 16 to 50 kg / m 3 The foam constituting the hardness-increasing material 35 is preferably expanded polystyrene (EPS), expanded polypropylene (EPP), or a polystyrene-polyolefin composite foam material.

[0045] The thickness of the vehicle floor silencer 30 is preferably 2 to 50 mm. The ratio of the thickness of the polyurethane foam 31 to the thickness of the hardness-increasing material 35 is preferably 1:1 to 4:1. If the ratio of the thickness of the polyurethane foam 31 is too low, the sound insulation of the vehicle floor silencer 30 decreases.

[0046] The 25% compression hardness of the vehicle floor silencer 30 is preferably 30 to 200 N. The 25% compression hardness of the portion of only the polyurethane foam 31 where the hardness-increasing material 35 is not laminated is preferably 30 to 70 N, and the 25% compression hardness of the portion of the polyurethane foam 31 and the hardness-increasing material 35 laminated is preferably 70 to 200 N.

[0047] The average transmission loss (JIS A1441-1:2007) of the vehicle floor silencer 30 from 1 to 4 kHz is 60 to 65 dB, and the laminated portion can also reduce solid-borne sound from the floor panel, thereby improving the sound insulation of the vehicle floor silencer 30.

[0048] A manufacturing example of the vehicle floor silencer 30 will be shown. The vehicle floor silencer 30 can be manufactured by molding using a die 40 shown in Fig. 4. The mold surface of the die 40 is determined according to the shape required for the vehicle floor silencer 30.

[0049] After applying a mold release agent to the surface of the mold 40, the mold 40 The hardness-enhancing material 35 is placed on the mold surface (the mold surface of the lower mold 41 or the upper mold 43). The mold surface on which the hardness-enhancing material 35 is placed is provided with a locking means such as a locking pin for removably holding the hardness-enhancing material 35.

[0050] After the hardness-increasing material 35 is placed, polyurethane foam raw material 31a is mixed and injected into the mold 40, which is then closed. The polyurethane foam raw material 30a is expanded in the molding space between the mold surfaces of the lower mold 41 and the upper mold 43, and the polyurethane foam 31 is formed integrally with the hardness-increasing material 35. The polyurethane foam raw material 31a is the same as the polyurethane foam raw material 11a described in the first embodiment. Thereafter, the mold 40 is opened, and the vehicle floor silencer 30 consisting of the laminated, integrated product of the polyurethane foam 31 and the hardness-increasing material 35 is demolded. EXAMPLES

[0051] Using polyurethane foam raw material with the composition shown in Figure 5, vehicle floor silencers of the examples and comparative examples, each 500 mm square x 20 mm thick, were manufactured by molding using the dies of Figures 2 and 4. The numerical values ​​of each component in the composition shown in Figure 5 are parts by weight. The dies were heated with hot water to a heating temperature of 65°C.

[0052] Examples 1 to 9 and Comparative Examples 1 to 4 are vehicle floor silencers made of polyurethane foam alone, and were manufactured using the mold shown in Fig. 2. Examples 10 and 11 are vehicle floor silencers made of a laminate of polyurethane foam and EPS (hardness-increasing material), and the polyurethane foam was molded integrally with the EPS using the mold shown in Fig. 4. The EPS used had a density of 33 kg / m 3 The dimensions are 10 mm thick × 450 mm × 450 mm in Example 10 and 10 mm thick × 350 mm × 250 mm in Example 11.

[0053] The components of the formulation shown in Figure 5 are as follows: Main polyol-1: Polyether polyol, functionality 3, number average molecular weight 7000, EO ratio 14%, product name; KC-737, manufactured by Sanyo Chemical Industries Main polyol-2: Polyether polyol, functionality 3, number average molecular weight 5000, EO ratio 14%, product name; FA-703, manufactured by Sanyo Chemical Industries Polymer polyol: functionality approximately 3, number average molecular weight 5000, product name; FM-5704, manufactured by Sanyo Chemical Industries Foam catalyst: Amine-based, product name; BL-11, manufactured by Evonik Resin catalyst: Amine-based, product name; 33LSI, manufactured by Evonik Co-catalyst: Amine-based, product name; TOYOCAT-D60, manufactured by Tosoh Corporation Cross-linking agent: Diethanolamine Foam stabilizer: Silicone-based, product name; B8738LF2, manufactured by Evonik Subpolyol: Polyether polyol, functional group number 3, number average molecular weight 4800, PO / EO=30 / 70 (EO ratio 70%), product name: CP1421, manufactured by Dow Chemical Company Blowing agent: Water Isocyanate: M5S, NCO%: 31.5%, manufactured by BASF INOAC Polyurethanes

[0054] For each of the examples and comparative examples, the PU (polyurethane foam) density, 25% compression hardness, and sound insulation were evaluated.

[0055] When the vehicle floor silencer is made of polyurethane foam alone, the polyurethane foam density (PU density) was measured on a sample cut to 100 mm square x 20 mm thick, based on JIS K7222: 2005. On the other hand, when polyurethane foam and EPS are laminated, the EPS was removed from the cut piece obtained by cutting to 100 mm square x 20 mm thick, and the polyurethane foam density (PU density) was measured on the remaining sample made of polyurethane foam, based on JIS K7222: 2005.

[0056] When the specimen consisted of polyurethane foam alone, the density was judged based on the polyurethane foam density (= overall density). On the other hand, when the specimen was laminated with polyurethane foam and EPS, the density was judged based on the calculated overall density consisting of polyurethane foam and EPS divided by the total mass of the specimen by the volume of the specimen. The standard for density was an overall density of 50 kg / m 3 "◎" if less than 50-70kg / m 3 "〇" if less than 70kg / m 3 In the above cases, the result was marked as “△”.

[0057] The 25% hardness was measured by cutting a sample to 200 mm square and 20 mm thick, with one side facing up in the case of polyurethane foam alone, or with the EPS facing up in the case of a laminate of polyurethane foam and EPS, and compressing it with a φ80 mm compression tool at a compression speed of 50 mm / min until the displacement was 80% of the thickness (sample displacement 16 mm, remaining sample thickness 4 mm), and reading the load at 25% compression as the 25% compression hardness.

[0058] The criteria for judging the hardness were as follows: "◎" for a 25% compression hardness of 100 N or more, "◯" for 30 N to less than 1000 N, and "△" for less than 30 N. The judgment of hardness corresponds to the judgment of the comfort of stepping on the ground.

[0059] The sound insulation was judged based on the transmission loss measured according to JIS A1441-1:2007. The sound insulation was judged based on the obtained transmission loss value. The sound source reverberation room used was 36m 3 , anechoic chamber is 20m 3 , the measurement area is 400 × 400 mm (0.16 m 2 In both cases where the vehicle floor silencer is made of polyurethane foam alone or EPS laminate, a 0.8 mm thick steel plate (sound insulation material) is placed on the surface of the polyurethane foam that is the sound source side, and a 1 mm thick rubber sheet (sound insulation material) (1700 g / m2) is placed on the opposite surface that is not the sound source (the polyurethane foam surface in the case of polyurethane foam alone, and the EPS surface in the case of EPS laminate).2 ) was placed on top of the floor silencer, and the gaps were sealed with clay while the vehicle floor silencer was fixed with a 50mm wide frame. Sound was irradiated from the iron plate side as the sound source, and the values ​​were measured at 4 centrally separated points (100mm pitch) 100mm away from the surface of the rubber sheet on the non-sound source side at 400Hz-6.3kHz, and the average value of 1kHz-4kHz and the average value of 400Hz-6.3kHz were calculated.

[0060] The criteria for judging sound insulation were as follows: an average value between 1 kHz and 4 kHz of 64 dB or more was marked "◎", an average value between 60 dB and less than 64 dB was marked "◯", and an average value less than 60 dB was marked "△".

[0061] Examples 1 to 3 are examples in which the amount of sub-polyol was changed to 2.5 parts by weight, 5 parts by weight, and 10 parts by weight. The amounts of main polyol 1 and main polyol 2 were constant at 50 parts by weight, and the amount injected into the mold was also constant (constant density). Examples 1 to 3 were judged as follows: density "good", hardness "good", and sound insulation "◎", and the lightweight, hardness (stepping comfort), and sound insulation were all good.

[0062] In Examples 4 to 6, the polyurethane foam raw materials were mixed in the same manner as in Example 1, and the polyurethane foam density was adjusted to 45 kg / m by changing the amount of foam injected into the mold. 3 , 50kg / m 3 , 55kg / m 3 It should be noted that Example 5 is the same as Example 1. Examples 4 to 6 were judged as having a density judgement of "◎" or "◯", a hardness judgement of "◯", and a sound insulation judgement of "◎", and were all good in terms of lightness, hardness (stepping comfort), and sound insulation.

[0063] Examples 7 to 9 are examples in which the subpolyol was 10 parts by weight, the isocyanate index was changed to 70, 75, and 80, and the polyurethane foam density was constant. Example 7 is the same as Example 3. Examples 7 to 9 were judged as having a density rating of "good", a hardness rating of "good", and a sound insulation rating of "◎", and were all good in terms of lightness, hardness (stepping comfort), and sound insulation.

[0064] Examples 10 and 11 are examples of laminates of polyurethane foam and EPS, in which two types of EPS were used, 10 mm thick x 450 mm thick x 450 mm thick (Example 10) and 10 mm thick x 350 mm thick x 250 mm thick (Example 11). The judgments for Examples 10 and 11 were density judgment "◎", hardness judgment "◎", and sound insulation judgment "〇". In Examples 10 and 11, the density judgment and hardness (stepping comfort) judgment improved from "〇" to "◎" compared to other examples of polyurethane foam alone, and the sound insulation judgment slightly decreased from "◎" to "〇".

[0065] In Comparative Examples 1 to 3, the sub-polyol was not blended, the main polyol 1 was 15 parts by weight, the main polyol 2 was 75 parts by weight, and the polymer polyol was 10 parts by weight. The isocyanate index was changed to 80, 85, and 90, and the polyurethane foam density was 50 kg / m 3 The evaluations of Comparative Examples 1 to 3 were density evaluation "◯", hardness evaluation "◎", and sound insulation evaluation "△", and the sound insulation was inferior to that of Examples 1 to 11 in which a subpolyol was blended.

[0066] Comparative Example 4 is an example in which the blending amounts of main polyol 1, main polyol 2, and polymer polyol are the same as those of Comparative Examples 1 to 3, and the isocyanate index and polyurethane foam density are higher than those of Comparative Examples 1 to 3 and the other Examples. The results of Comparative Example 4 were density "△", hardness "◎", and sound insulation "◎", and the sound insulation was improved, but the light weight was poor due to the high density.

[0067] Thus, the present invention provides a vehicle floor silencer that is lightweight, has good sound insulation properties, and provides good stepping comfort (hardness). [Explanation of symbols]

[0068] 10, 30 Vehicle floor silencer 11, 31 Polyurethane foam 11a, 31a Polyurethane foam raw material 20, 40 Mold 21, 41 Lower mold 23, 43 Upper mold 35 Hardness increasing material

Claims

【Request 1】 A floor silencer for a vehicle comprising a polyurethane foam, the density of the polyurethane foam being 40 to 60 kg / m ３ The polyurethane foam has a 25% compression hardness of 30 to 200 N, and the polyurethane foam has an average transmission loss of 60 to 65 dB at 1 to 4 kHz as measured in accordance with JIS A1441-1:2007.

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