Vibration-damping material, laminate, and method for producing vibration-damping material

Abstract

To provide a vibration-damping material which exhibits outstanding vibration-damping performance, along with excellent moldability and workability, and is also useful as a recycled interlayer film for laminated glass; a laminate including the vibration-damping material; and a suitable method for producing such a vibration-damping material.SOLUTION: A vibration-damping material contains: polyvinyl acetal; a plasticizer; a tackifier; and a filler containing a plate-like inorganic filler.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a vibration damping material, a laminate, and a method for manufacturing the vibration damping material.

Background Art

[0002] A vibration damping material is a material that suppresses the generation of sound by converting vibration energy into heat energy, and is used, for example, in the floors, walls, ceilings of buildings such as houses, and the floors of vehicles.

[0003] By the way, in recent years, laminated glass obtained by sandwiching an interlayer film for laminated glass made of plasticized polyvinyl butyral or the like between a pair of glass plates and adhering them to each other has been widely used as vehicle glass for automobiles, airplanes, etc., and window glass for buildings. When manufacturing such laminated glass, when the interlayer film for laminated glass is bonded to the glass, the excess interlayer film for laminated glass at the end is cut off and becomes a large amount of waste. Also, when disassembling laminated glass that does not meet quality standards or used laminated glass, a large amount of the interlayer film for laminated glass is discarded. Therefore, from the viewpoints of reducing environmental impact and cost, etc., a technology for recycling waste of the interlayer film for laminated glass is required.

[0004] For example, Patent Document 1 discloses a technology for using a thermoplastic elastomer composition containing a recovered plasticized polyvinyl butyral resin, recycled rubber, and an inorganic filler in a waterproof structure, a soundproof structure, etc. In the examples, ground products of calcium carbonate and barium sulfate (barite powder) are used as the inorganic filler. Patent Document 2 discloses a technology for using a recycled material obtained by adding an inorganic filler to a recycled resin composition containing waste-derived polyvinyl butyral and a crosslinking agent and molding it in a sound insulation material, a soundproof material, etc. In the examples, barium sulfate and carbon are used at a high volume ratio as the inorganic filler.

Prior Art Documents

Patent Documents

[0005] Patent Document 1 Japanese Patent Application Laid-Open No. 2016-94515 Patent Document 2 Japanese Patent Application Laid-Open No. 2018-83939 Summary of the Invention Problems to be Solved by the Invention

[0006] However, the compositions described in Patent Document 1 and the recycled materials described in Patent Document 2 have problems in terms of workability and the like because they do not have sufficient vibration damping properties and the specific gravity of barium sulfate used as a filler is large.

[0007] In view of the above situation, an object of the present invention is to provide a vibration damping material that is extremely excellent in vibration damping properties, has good moldability, workability, etc., and is also useful as a recycled product of an interlayer film for laminated glass, and a laminate including the vibration damping material. Another object of the present invention is to provide a manufacturing method suitable for obtaining such a vibration damping material. Means for Solving the Problems

[0008] The inventors of the present invention, while studying a technique for recycling waste of an interlayer film for laminated glass, focused on the fact that a composition containing a polyvinyl acetal such as polyvinyl butyral, a plasticizer, a tackifier, and a filler is suitable for use as a vibration damping material. In particular, it has been found that when the composition essentially contains a plate-like inorganic filler as a filler, it becomes a material that is extremely excellent in vibration damping properties and has good moldability, workability, etc.

[0009] Conventional vibration damping materials are usually used with a restraint material (also referred to as a restraint layer) made of a metal plate such as an aluminum plate in order to easily convert vibration energy into thermal energy. However, the inventors of the present invention have found that a vibration damping material containing the above-mentioned polyvinyl acetal, a plasticizer, a tackifier, and a filler containing a plate-like inorganic filler exhibits high vibration damping performance due to a large energy loss at the interface between the plate-like inorganic filler and a resin such as polyvinyl acetal when vibration is applied, and the plate-like inorganic filler can also function as a restraint material. Therefore, the vibration damping material can exhibit high vibration damping performance even without the restraint material being laminated. Accordingly, the above vibration damping material exhibits high vibration damping performance, has no limitation on the installation location, has high versatility, and can be manufactured at low cost. The inventors have also found that since the plate-like inorganic filler has a smaller specific gravity than, for example, barium sulfate, the above vibration damping material can also achieve weight reduction and improved workability. In addition, by including a tackifier, the above vibration damping material can suppress, for example, the mixture from adhering to or sticking to a kneader during the production of the vibration damping material, and thus has good handleability.

[0010] In this way, the inventors have found that the above vibration damping material has extremely excellent vibration damping performance due to the synergistic effect of including polyvinyl acetal, a plasticizer, a tackifier, and a plate-like inorganic filler, and also has good moldability, workability, etc., and thus have completed the present invention. The above vibration damping material is also effective as a recycled product of an interlayer film for laminated glass, and can reduce the environmental load and cost.

[0011] The present disclosure 1 is a vibration damping material containing polyvinyl acetal, a plasticizer, a tackifier, and a filler containing a plate-like inorganic filler. The present disclosure 2 is the vibration damping material of the present disclosure 1, wherein the content of the above plate-like inorganic filler is 10% by mass or more and 80% by mass or less based on 100% by mass of the total amount of the above vibration damping material. The present disclosure 3 is the vibration damping material of the present disclosure 1 or 2, wherein the content of the above filler is 48% by mass or more and 80% by mass or less based on 100% by mass of the total amount of the above vibration damping material. The present disclosure 4 is a vibration damping material according to any one of the present disclosures 1 to 3, wherein the plate-shaped inorganic filler is a layered silicate. The present disclosure 5 is a vibration damping material according to any one of the present disclosures 1 to 4, wherein the plate-shaped inorganic filler is mica. The present disclosure 6 is a vibration damping material according to any one of the present disclosures 1 to 5, which uses a plate-shaped inorganic filler having a particle size of 100 mesh or less as a raw material. The present disclosure 7 is a vibration damping material according to any one of the present disclosures 1 to 6, wherein the polyvinyl acetal contains polyvinyl butyral, and the plasticizer contains triethylene glycol di-2-ethylhexanoate.

[0012] The present disclosure 8 is a vibration damping material according to any one of the present disclosures 1 to 7, wherein the loss factor with respect to each resonance frequency of mechanical impedance measurement (MIM) measured in accordance with JIS K7391 (2008) is 0.05 or more at 20 ° C and 100 to 3000 Hz. The present disclosure 9 is a vibration damping material according to any one of the present disclosures 1 to 8, further comprising a catcher agent for capturing aldehydes. The present disclosure 10 is a vibration damping material according to the present disclosure 9, wherein the catcher agent is amorphous silica. The present disclosure 11 is a vibration damping material according to any one of the present disclosures 1 to 10, which is sheet-shaped. The present disclosure 12 is a vibration damping material according to the present disclosure 11, having a thickness of 0.5 mm or more and 8 mm or less. The present disclosure 13 is a method for manufacturing the vibration damping material according to the present disclosure 11 or 12, comprising a step of adding a filler containing a plate-shaped inorganic filler to a resin composition containing polyvinyl acetal, a plasticizer, and a tackifier, and a step of sheet-forming the mixture obtained by the step. The present disclosure 14 is a method for manufacturing the vibration damping material according to the present disclosure 13, wherein the particle size of the plate-shaped inorganic filler is 100 mesh or less. The present disclosure 15 is a laminate in which at least one laminate selected from the group consisting of a nonwoven fabric, aluminum, polyethylene terephthalate, high-density polyethylene, and a glass cloth sheet is laminated on at least one main surface of the vibration damping material according to the present disclosure 11 or 12. The present invention will be described in detail below.

[0013] (Vibration damping material) The vibration damping material of the present invention contains polyvinyl acetal, a plasticizer, a tackifier, and a filler. The filler essentially contains a plate-like inorganic filler. Note that the vibration damping material may further contain other components as necessary. Each of the contained components may be one type or two or more types.

[0014] Examples of the shape of the above vibration damping material include a sheet shape, a plate shape, a rod shape, a block shape, etc., but a sheet shape is preferred. That is, the above vibration damping material is preferably a vibration damping sheet. Note that the "sheet" is not limited to a strict meaning based on thickness, and usually includes a thin one called "film" and a thick one called "plate". The thickness of the vibration damping sheet is not particularly limited, but considering the vibration damping effect and handleability during construction, etc., for example, it is preferably 0.05 mm or more and 50 mm or less, and more preferably 0.5 mm or more and 8 mm or less. The above thickness is the maximum thickness of the vibration damping sheet.

[0015] The above polyvinyl acetal is preferably a polyvinyl acetal obtained by acetalizing polyvinyl alcohol with an aldehyde.

[0016] The above polyvinyl alcohol is usually obtained by saponifying polyvinyl acetate. The degree of saponification is generally 70 to 99.8 mol%, and preferably 80 to 99.8 mol%.

[0017] The average degree of polymerization of the above polyvinyl alcohol is preferably 200 or more, more preferably 500 or more, still more preferably 1700 or more, particularly preferably 2000 or more, and also preferably 5000 or less, more preferably 4000 or less, even more preferably 3000 or less, still more preferably less than 3000, particularly preferably less than 2800. The above polyvinyl acetal is preferably obtained by acetalizing polyvinyl alcohol having such a degree of polymerization. The average degree of polymerization of polyvinyl alcohol is determined by a method in accordance with JIS K6726 (1994) "Test Methods for Polyvinyl Alcohol".

[0018] As the above aldehyde, generally, aldehydes having 1 to 10 carbon atoms are preferably used. Examples of the aldehydes having 1 to 10 carbon atoms include formaldehyde, acetaldehyde, propionaldehyde, n-butylaldehyde, isobutylaldehyde, n-valeraldehyde, 2-ethylbutylaldehyde, n-hexylaldehyde, n-octylaldehyde, n-nonylaldehyde, n-decylaldehyde, benzaldehyde and the like. Among them, n-butylaldehyde, n-hexylaldehyde or n-valeraldehyde is preferable, and n-butylaldehyde is more preferable.

[0019] Among the above polyvinyl acetals, polyvinyl butyral is preferable from the viewpoint of improving weather resistance and the like. That is, it is preferable that the above polyvinyl acetal contains polyvinyl butyral. In 100% by mass of the polyvinyl acetal, the content of polyvinyl butyral is preferably 50% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and particularly preferably 100% by mass.

[0020] Examples of the above plasticizer include organic ester plasticizers such as monobasic organic acid esters and polybasic organic acid esters, phosphoric acid plasticizers such as organic phosphoric acid plasticizers and organic phosphorous acid plasticizers. The plasticizer is preferably a liquid plasticizer.

[0021] Examples of the above-mentioned monobasic organic acid esters include glycol esters obtained by reacting glycols such as triethylene glycol, tetraethylene glycol, and tripropylene glycol with monobasic organic acids such as butyric acid, isobutyric acid, caproic acid, 2-ethylbutyric acid, heptylic acid, n-octylic acid, 2-ethylhexanoic acid, pelargonic acid (n-nonanoic acid), and decylic acid. Among them, triethylene glycol dicaprate, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-n-octylate, triethylene glycol di-2-ethylhexanoate, etc. are preferred.

[0022] Examples of the above-mentioned polybasic organic acid esters include ester compounds of polybasic organic acids such as adipic acid, sebacic acid, and azelaic acid with alcohols having a linear or branched structure with 4 to 8 carbon atoms. Among them, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, etc. are preferred.

[0023] As the above-mentioned organic ester plasticizer, for example, triethylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylhexanoate, triethylene glycol dicaprylate, triethylene glycol di-n-octanoate, triethylene glycol di-n-heptanoate, tetraethylene glycol di-n-heptanoate, tetraethylene glycol di-2-ethylhexanoate, dibutyl sebacate, dioctyl azelate, dibutyl carbitol adipate, ethylene glycol di-2-ethylbutyrate, 1,3-propylene glycol di-2-ethylbutyrate, 1,4-butylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylbutyrate, diethylene glycol di-2-ethylhexanoate, dipropylene glycol di-2-ethylbutyrate, triethylene glycol di-2-ethylpentanoate, tetraethylene glycol di-2-ethylbutyrate, diethylene glycol dicaprylate, dihexyl adipate, dioctyl adipate, hexyl cyclohexyl adipate, diisononyl adipate, heptyl nonyl adipate, dibutyl sebacate, oil-modified sebacic acid alkyd, a mixture of phosphate ester and adipic acid ester, adipic acid ester, a mixed adipic acid ester prepared from an alkyl alcohol having 4 to 9 carbon atoms and a cyclic alcohol having 4 to 9 carbon atoms, adipic acid esters having 6 to 8 carbon atoms such as hexyl adipate, etc. may be mentioned.

[0024] As the above-mentioned organic phosphate plasticizer, for example, tributoxyethyl phosphate, isodecyl phenyl phosphate, triisopropyl phosphate, etc. may be mentioned.

[0025] As the plasticizer, from the viewpoint of being less likely to cause hydrolysis, triethylene glycol di-2-ethylhexanoate (also referred to as 3GO), triethylene glycol di-2-ethylbutyrate (3GH), tetraethylene glycol di-2-ethylhexanoate (also referred to as 4GO), and / or dihexyl adipate (also referred to as DHA) are preferably used. As the plasticizer, more preferably, it is 4GO and / or 3GO, and still more preferably, it is 3GO. In 100% by mass of the plasticizer, it is preferable that 3GO is 50% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, and particularly preferably 100% by mass.

[0026] In the above vibration damping material, it is particularly preferable that the polyvinyl acetal contains polyvinyl butyral and the plasticizer contains triethylene glycol di-2-ethylhexanoate (3GO).

[0027] The content of the plasticizer is preferably 10 parts by weight or more and 80 parts by weight or less with respect to 100 parts by weight of polyvinyl acetal (when the above vibration damping material further contains other resins, it means 100 parts by weight of the total amount of resin components). When the content of the plasticizer is within this range, various performances such as shock absorbency can be enhanced, and the bleed-out of the plasticizer from the vibration damping material can also be sufficiently suppressed. The content of the plasticizer is more preferably 20 parts by weight or more, still more preferably 30 parts by weight or more, and the upper limit is more preferably 60 parts by weight or less, still more preferably 50 parts by weight or less. The preferable range of the content of the plasticizer is 10 parts by weight or more and 80 parts by weight or less, the more preferable range is 20 parts by weight or more and 60 parts by weight or less, and the still more preferable range is 30 parts by weight or more and 50 parts by weight or less.

[0028] Examples of the tackifier include petroleum resins such as aliphatic copolymers (also referred to as aliphatic petroleum resins), aromatic copolymers (also referred to as aromatic petroleum resins), aliphatic-aromatic copolymers (also referred to as aliphatic-aromatic copolymer-based petroleum resins), alicyclic copolymers (also referred to as alicyclic petroleum resins), coumarone-indene resins, terpene resins, terpene phenol resins, rosin resins such as polymerized rosin, (alkyl)phenol resins, xylene resins, and hydrogenated products thereof. Among them, from the viewpoint of improving vibration damping properties, it is preferable that the tackifier is a petroleum resin, and more preferably a hydrogenated product of a petroleum resin (also referred to as a hydrogenated petroleum resin). When the vibration damping material contains a hydrogenated petroleum resin, the vibration damping property is further improved, the odor is suppressed, and moreover, the adhesion or sticking of the mixture to the kneader during the production of the vibration damping material can be further suppressed.

[0029] A petroleum resin is obtained by polymerizing a fraction containing unsaturated hydrocarbons produced as a by-product by thermal decomposition of petroleum naphtha or the like to resinify it. Specifically, examples of the petroleum resin include aliphatic petroleum resins obtained by copolymerizing a C5 fraction containing pentenes, isoprene, piperine, etc. produced by thermal decomposition of petroleum naphtha, aromatic petroleum resins polymerized mainly from a C9 fraction, and dicyclopentadiene-based petroleum resins. Among them, as described above, it is preferable that the tackifier is a hydrogenated petroleum resin, and from the viewpoints of productivity and improvement of vibration damping properties, it is particularly preferable that it is an aromatic hydrogenated petroleum resin obtained by hydrogenating a C9-based petroleum resin (i.e., a hydrogenated product of a C9-based petroleum resin).

[0030] The above petroleum resin preferably also has a softening point of 100°C or higher. Thereby, the vibration damping property is further improved, and a higher vibration damping and sound insulation effect can be exhibited in the temperature range of 0 to 40°C, especially 5 to 25°C. The softening point is more preferably 120°C or higher, and even more preferably 130°C or higher. When the softening point is higher, plastic deformation of the resin can be suppressed, so that a higher vibration damping property can be exhibited. The upper limit of the softening point is not particularly limited, but for example, it is preferably 200°C or lower. Thereby, a decrease in the loss factor of the vibration damping material is suppressed, and it is sufficiently suppressed that the vibration damping material becomes too brittle. The above softening point is more preferably 180°C or lower, even more preferably 150°C or lower, and particularly preferably 145°C or lower. In particular, when the above vibration damping material contains a hydrogenated petroleum resin having a softening point of 100°C or higher, it can be a vibration damping material that is more excellent in vibration damping property and productivity and is also very suitable from the viewpoint of odor suppression.

[0031] It is also preferable to use in combination petroleum resins having different softening points as the above tackifier. For example, when the above vibration damping material contains a petroleum resin (A) having a softening point of 130°C or higher and a petroleum resin (B) having a softening point of less than 130°C, from the viewpoint of improving the vibration damping property, the petroleum resin (A) in the total amount of these is preferably 30% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, still more preferably 70% by mass or more, particularly preferably 80% by mass or more, even more preferably 90% by mass or more, and most preferably 100% by mass. In particular, the above vibration damping material preferably contains a hydrogenated petroleum resin having a softening point of 130°C or higher.

[0032] The content of the above tackifier is preferably 1 part by weight or more and 50 parts by weight or less, for example, based on 100 parts by weight of polyvinyl acetal (when the above vibration damping material further contains other resins, it means 100 parts by weight of the total amount of resin components). When the content of the tackifier is within this range, it is more suppressed that the mixture adheres or sticks to the kneader during the production of the vibration damping material, the workability and constructability are better, and the sheet forming becomes easier. The content of the above tackifier is more preferably 2 parts by weight or more, still more preferably 5 parts by weight or more, particularly preferably 10 parts by weight or more, and the upper limit is more preferably 40 parts by weight or less, still more preferably 30 parts by weight or less. The preferable range of the content of the tackifier is 1 part by weight or more and 50 parts by weight or less, the more preferable range is 2 parts by weight or more and 40 parts by weight or less, the still more preferable range is 5 parts by weight or more and 30 parts by weight or less, and the particularly preferable range is 10 parts by weight or more and 30 parts by weight or less.

[0033] The above filler essentially contains a plate-like inorganic filler. The plate-like inorganic filler is an inorganic filler having a plate-like shape. Among the plate-like shapes, it is preferably scaly (that is, a thin plate-like shape, meaning a shape in which the thickness is extremely small with respect to the maximum dimension). As the plate-like inorganic filler, for example, layered inorganic fillers such as mica, talc, graphite, sericite, and kaolin are preferable, layered silicates are more preferable, and mica is still more preferable. In addition, as the above filler, a masterbatch product of the above filler may be used.

[0034] The above-mentioned plate-shaped inorganic filler preferably has a particle size of 100 mesh or less, more preferably 60 mesh or less, as the raw material for manufacturing the vibration damping material. That is, it is preferable that the vibration damping material uses a plate-shaped inorganic filler with a particle size of 100 mesh or less as the raw material, and it is more preferable that it uses a plate-shaped inorganic filler with a particle size of 60 mesh or less as the raw material. The above-mentioned particle size (particle size as the raw material) is more preferably 40 mesh or less, and particularly preferably 20 mesh or less. When manufacturing a vibration damping material using a plate-shaped inorganic filler with a relatively coarse particle size as the raw material, the function as a constraining material by the plate-shaped inorganic filler in the obtained vibration damping material is more exerted, so the vibration damping performance of the vibration damping material is further enhanced. The lower limit of the above-mentioned particle size is not particularly limited, and it is preferably 1 mesh or more. In addition, the above-mentioned particle size (mesh) is a value measured in accordance with JIS Z8801-1 (2009). For example, the opening dimension of 100 mesh is 150 μm.

[0035] The content of the above-mentioned plate-shaped inorganic filler is preferably 10% by mass or more based on 100% by mass of the total amount of the vibration damping material. Thereby, the plate-shaped inorganic filler can more fully exert its function as a constraining material. From the viewpoint of further exerting this effect, the content of the plate-shaped inorganic filler with respect to 100% by mass of the total amount of the vibration damping material is more preferably 15% by mass or more, 25% by mass or more, 30% by mass or more, 40% by mass or more, 45% by mass or more, 60% by mass or more, 65% by mass or more in this order, and most preferably 70% by mass or more.

[0036] The content of the above plate-shaped inorganic filler is preferably 80% by mass or less based on 100% by mass of the total amount of the vibration damping material. This makes sheet forming easier. That is, a sheet-shaped vibration damping material (also referred to as a vibration damping sheet) can be obtained more easily. The range of the content of the plate-shaped inorganic filler based on 100% by mass of the total amount of the vibration damping material is preferably in the order of 10% by mass or more and 80% by mass or less, 15% by mass or more and 80% by mass or less, 25% by mass or more and 80% by mass or less, 30% by mass or more and 80% by mass or less, 40% by mass or more and 80% by mass or less, 45% by mass or more and 80% by mass or less, 60% by mass or more and 80% by mass or less, 65% by mass or more and 80% by mass or less, and most preferably 70% by mass or more and 80% by mass or less.

[0037] Also, when the total volume of the vibration damping material is 100% by volume, the volume content ratio of the above plate-shaped inorganic filler is preferably less than 70% by volume, and more preferably 60% by volume or less. The volume content ratio of the filler is preferably 10% by volume or more, more preferably 25% by volume or more, and still more preferably 30% by volume or more based on 100% by volume of the total volume of the vibration damping material.

[0038] The above filler may further contain one or more fillers other than the plate-shaped inorganic filler (also referred to as other fillers). The other fillers are not particularly limited, and examples include inorganic fillers having a shape other than plate-like such as spherical, and organic fillers. As the other fillers, for example, one or more of silica, glass beads, graphite, alumina, titanium oxide, wollastonite, barium sulfate, calcium carbonate, glass fiber, cellulose fiber, carbon fiber, carbon nanotube, carbon nanocoil, etc. are preferably used.

[0039] The content of the above-mentioned filler is preferably 48% by mass or more, more preferably 60% by mass or more, still more preferably 65% by mass or more, and particularly preferably 70% by mass or more with respect to 100% by mass of the total amount of the above-mentioned vibration damping material. From the viewpoint of sheet formability, the content of the above-mentioned filler is preferably 80% by mass or less with respect to 100% by mass of the total amount of the above-mentioned vibration damping material. The preferable range of the content of the filler is from 48% by mass to 80% by mass, the more preferable range is from 60% by mass to 80% by mass, the still more preferable range is from 65% by mass to 80% by mass, and the particularly preferable range is from 70% by mass to 80% by mass. Note that the content of the filler means the content of only the plate-like inorganic filler when only the plate-like inorganic filler is included as the filler, and means the total content of these when the filler includes the plate-like inorganic filler and other fillers.

[0040] In addition, when the total volume of the above-mentioned vibration damping material is 100% by volume, the volume content ratio of the above-mentioned filler is preferably less than 70% by volume, and more preferably 60% by volume or less. The volume content ratio of the above-mentioned filler is preferably 10% by volume or more, and more preferably 20% by volume or more with respect to 100% by volume of the total volume of the above-mentioned vibration damping material.

[0041] In the above-mentioned vibration damping material, the content ratio of the plate-like inorganic filler and other fillers depends on, for example, the specific gravity and thickness when the vibration damping material is in the form of a sheet (i.e., a vibration damping sheet). For example, the mass ratio (plate-like inorganic filler / other fillers) is preferably 30 - 100 / 0 - 70, more preferably 50 - 100 / 0 - 50, still more preferably 70 - 100 / 0 - 30, and particularly preferably 90 - 100 / 0 - 10. The form in which the above-mentioned vibration damping material contains only the plate-like inorganic filler as the filler is also preferable.

[0042] In the vibration damping material of the present invention, the proportion of polyvinyl acetal, plasticizer, tackifier, and filler preferably ranges from 50% by mass to 100% by mass, more preferably from 60% by mass to 100% by mass, still more preferably from 70% by mass to 100% by mass, and particularly preferably from 80% by mass to 100% by mass.

[0043] In addition to polyvinyl acetal, plasticizer, tackifier, and filler, the vibration damping material of the present invention may contain, for example, one or more of various additives such as a catcher agent for capturing aldehydes, a release agent, an adhesion adjuster, a heat ray absorber, an ultraviolet ray blocker, an antioxidant, a light stabilizer, an antistatic agent, a thermoplastic elastomer, and a liquid crystal polymer. Further, in order to adjust the appearance of the vibration damping material (for example, a vibration damping sheet), it may contain one or more pigments such as carbon black or dyes as a coloring agent.

[0044] For example, it is preferable that the above vibration damping material further contains a catcher agent for capturing aldehydes. Since the polyvinyl acetal may have an aldehyde group in its acetyl group or the like, it may have an odor peculiar to aldehydes. However, when the above vibration damping material further has a catcher agent for capturing aldehydes, the generation of odor is sufficiently suppressed.

[0045] Examples of the catcher agent include porous particles such as zeolite, activated alumina, activated clay, sepiolite, iron oxide, zinc oxide, magnesium oxide, aluminum silicate, and silica; aldehyde adsorption compounds having groups capable of adsorbing to aldehyde molecules such as amino groups, imino groups, amide groups, and hydrazide groups. Among them, the catcher agent is preferably porous particles, more preferably silica, and still more preferably amorphous silica. Note that the porous particles may have a group capable of adsorbing to the above aldehyde molecules.

[0046] When the vibration damping material contains a catcher agent, the content of the catcher agent is preferably 0.01 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, based on 100 parts by weight of polyvinyl acetal.

[0047] In addition, a non-woven fabric impregnated with a catcher agent may be laminated on the vibration damping material. For example, a laminate in which a non-woven fabric impregnated with a catcher agent is laminated on at least one main surface of a sheet-like vibration damping material (i.e., a vibration damping sheet) is included in the laminate of the present disclosure described later.

[0048] The loss factor of the vibration damping material of the present invention with respect to each resonance frequency of mechanical impedance measurement (MIM) measured in accordance with JIS K7391 (2008) is preferably 0.05 or more, more preferably 0.07 or more, still more preferably 0.1 or more, and particularly preferably 0.13 or more at 20 °C and 100 to 3000 Hz. Further, the resonance frequency at which the loss factor satisfies these preferable ranges is preferably, for example, the second resonance frequency, more preferably the second and third resonance frequencies, still more preferably the second, third and fourth resonance frequencies, and particularly preferably the second, third, fourth and fifth resonance frequencies. Note that since the higher the loss factor is, the more preferable it is, the upper limit of the loss factor is not particularly limited.

[0049] Specifically, for example, when the loss factor and the resonance frequency are measured by the vibration damping property evaluation test described later, the loss factor is preferably 0.05 or more, more preferably 0.07 or more, still more preferably 0.1 or more, and particularly preferably 0.13 or more at 20 °C and 300 Hz or more and 800 Hz or less.

[0050] The vibration damping material of the present invention may be made from waste of an interlayer film for laminated glass. The vibration damping material is extremely useful for establishing the recycling of the interlayer film for laminated glass and can sufficiently contribute to reducing the environmental load and cost.

[0051] When using the waste of the interlayer film for laminated glass as a raw material for the vibration damping material, if the waste already contains polyvinyl acetal, a plasticizer, a tackifier, and a plate-like inorganic filler, the waste or a product further blended with various additives, etc. as necessary can be used as the vibration damping material. When the vibration damping material does not contain any one or more of polyvinyl acetal, a plasticizer, a tackifier, and a plate-like inorganic filler, or when the content of the contained components does not meet the above-described preferable range, a product obtained by blending the component into the waste or a product further blended with various additives, etc. as necessary can be used as the vibration damping material.

[0052] (Method for manufacturing a vibration damping material) As a method for manufacturing the vibration damping material of the present invention, a method including a step of adding a filler containing a plate-like inorganic filler as an essential component to a resin composition containing polyvinyl acetal, a plasticizer, and a tackifier is preferable. Particularly when the vibration damping material is in a sheet form, the manufacturing method of the vibration damping material (vibration damping sheet) preferably includes a step of adding a filler containing a plate-like inorganic filler to a resin composition containing polyvinyl acetal, a plasticizer, and a tackifier (also referred to as step (1)), and a step of forming the mixture obtained by the step (1) into a sheet (also referred to as step (2)). Note that the vibration damping material obtained by the above manufacturing method is one of the preferable forms of the present invention.

[0053] In the above step (1), the resin composition contains polyvinyl acetal, a plasticizer, and a tackifier. As necessary, the resin composition may further contain the various additives and colorants described above. In the above step (1), after adding a filler such as a plate-like inorganic filler to the resin composition, it is preferable to mix them. The above step (1) is performed, for example, in a heating environment using a kneader or the like. Each contained component can be used singly or in two or more kinds. Note that a masterbatch product of the filler (including a plate-like inorganic filler) may be used as the filler so that the filler does not scatter during weighing, charging, or kneading.

[0054] The compounding amounts of the respective raw materials used in the above step (1) are preferably set such that the content ratios in the obtained vibration damping material are within the above-described preferable ranges.

[0055] As described above, the particle size of the plate-like inorganic filler used as a raw material is preferably 100 mesh or less, more preferably 60 mesh or less, still more preferably 40 mesh or less, and particularly preferably 20 mesh or less. The lower limit of the above particle size is not particularly limited, and it is preferably 1 mesh or more.

[0056] The above step (2) is preferably a step of shaping the mixture obtained in the above step (1) into a sheet-like original fabric. For example, it is preferable to produce a vibration damping sheet by extruding the above mixture with an extruder. Thereafter, it is preferable to perform a step of laminating a laminate such as a non-woven fabric on at least one main surface of the obtained vibration damping sheet, whereby the laminate of the present invention described later can be preferably obtained.

[0057] (Laminate) In the laminate of the present invention, at least one laminate selected from the group consisting of a non-woven fabric, aluminum, polyethylene terephthalate (also referred to as PET), high-density polyethylene (also referred to as HDPE), and a glass cloth sheet is laminated on at least one main surface of the sheet-like vibration damping material (i.e., vibration damping sheet). Note that the above aluminum, PET, HDPE, and glass cloth sheet are preferably in a sheet shape (including a film shape).

[0058] Among the above laminates, the non-woven fabric is not particularly limited as long as it has minute voids. The material (texture) of the non-woven fabric is not particularly limited, and examples thereof include natural fibers such as cellulose, silk, hemp, and pulp; synthetic fibers such as polyester, nylon, rayon, polyethylene, polypropylene, polyurethane, and polyethylene terephthalate; blends thereof; and the like. Among the synthetic fibers of the non-woven fabric, synthetic fibers obtained from thermoplastic resins are preferred, and pulp and / or polyester are more preferred. A binder may be used for the non-woven fabric as necessary, and it may be colored as necessary. As described above, the non-woven fabric may be a non-woven fabric in which a catcher agent is kneaded.

[0059] As the above aluminum, for example, an aluminum plate generally used as a constraining material is preferably used. As described above, the vibration damping material of the present invention can exhibit high vibration damping performance even without laminating a constraining material. However, by further laminating a constraining material such as aluminum to the vibration damping material of the present invention, a laminate having even more excellent vibration damping performance can be obtained.

[0060] The thickness of the laminate laminated on the main surface of the vibration damping sheet is preferably, for example, such that the maximum thickness of each layer of the laminate is 0.02 mm or more and 1 mm or less. When the maximum thickness is within this range, the handleability of the laminate is further improved. The more preferable range of the maximum thickness varies depending on the type of the laminate used, etc. For example, when aluminum is used as the laminate, it is more preferable that the maximum thickness of the layer composed of aluminum is 0.03 mm or more and 0.5 mm or less, and it is still more preferable that it is 0.05 mm or more and 0.3 mm or less. Further, when PET (excluding the non-woven fabric made of PET) is used as the laminate, it is more preferable that the maximum thickness of the layer composed of PET is 0.02 mm or more and 0.5 mm or less, it is still more preferable that it is 0.02 mm or more and 0.1 mm or less, and it is particularly preferable that it is 0.02 mm or more and 0.05 mm or less. Further, when a non-woven fabric is used as the laminate, it is more preferable that the maximum thickness of the layer composed of the non-woven fabric is 0.02 mm or more and 0.5 mm or less, it is still more preferable that it is 0.03 mm or more and 0.1 mm or less, and it is particularly preferable that it is 0.04 mm or more and 0.05 mm or less.

[0061] The above laminate may be laminated on at least one main surface of the vibration damping sheet, but it is preferable to laminate it on the main surfaces of both sides of the vibration damping sheet. "Laminating on the main surface" means laminating so as to cover 50% or more of the total area of the surface to be laminated. It is preferable to laminate so as to cover 70% or more of the total area of 100%, more preferably 80% or more, and still more preferably 90% or more. The upper limit may be 100% or less.

[0062] The above laminate may be cut (i.e., sliced) into an appropriate size and then laminated. Also in that case, it is preferable to laminate the laminate so as to cover the above-described ratio with respect to the total area of 100% of the laminated surface.

Advantages of the Invention

[0063] According to the present invention, it is possible to provide a vibration damping material that is extremely excellent in vibration damping properties, has good moldability, workability, etc., and is also useful as a recycled product of an interlayer film for laminated glass, and a laminate including the vibration damping material. The present invention can also provide a production method suitable for obtaining such a vibration damping material.

Brief Description of the Drawings

[0064]

Figure 1A

Figure 1B

Figure 1C

Figure 2A

Figure 2B

Figure 3A

Figure 3B

Modes for Carrying Out the Invention

[0065] Hereinafter, embodiments will be given to explain the aspects of the present invention in more detail, but the present invention is not limited only to these embodiments. Note that wt% means weight%, vol% means volume%, and part means part by weight.

[0066] In the following examples, the following compounds, etc. were used as raw material components. (1) Polyvinyl butyral: hydroxyl group content 31 mol%, degree of acetylation 0.7 mol%, degree of butyralization 68.3 mol%, average degree of polymerization 1800, manufactured by Sekisui Chemical Co., Ltd. (2) Plasticizer: Triethylene glycol di-2-ethylhexanoate (3GO), manufactured by Sekisui Chemical Co., Ltd. (3) Tackifier: Alcon M-135, manufactured by Arakawa Chemical Industries, Ltd. (softening point 135°C) (4) Release agent: Powdered stearic acid Sakura, manufactured by NOF Corporation (5) Colorant: Carbon black, manufactured by Tokai Carbon Co., Ltd., Seast SP (6) Filler · Barium sulfate: A-200, manufactured by Takehara Chemical Industry Co., Ltd. (see FIGS. 2A and 2B) · Calcium carbonate: R heavy carbonate, manufactured by Maruo Calcium Co., Ltd. (see FIGS. 3A and 3B) · Mica 60: Chinese white mica (dry-ground product), 60 mesh, flaky, manufactured by Yama Industries Co., Ltd. (see FIG. 1A) · Mica 40: Chinese white mica (dry-ground product), 40 mesh, flaky, manufactured by Yama Industries Co., Ltd. (see FIG. 1B) · Mica 20: Chinese white mica (dry-ground product), 20 mesh, flaky, manufactured by Yama Industries Co., Ltd. (see FIG. 1C)

[0067] FIGS. 1A, 1B, and 1C are scanning electron microscope photographs (also referred to as SEM photographs) of mica 60, mica 40, and mica 20, respectively. In each figure, the magnification is 100 times. As can be seen from FIGS. 1A, 1B, and 1C, the shapes of mica 60, mica 40, and mica 20 were all plate-like (more precisely, flaky). FIGS. 2A and 2B are SEM photographs of barium sulfate, and FIGS. 3A and 3B are SEM photographs of calcium carbonate. In FIGS. 2A and 3A, the magnification is 100 times, and in FIGS. 2B and 3B, the magnification is 500 times. As can be seen from FIGS. 2A, 2B, 3A, and 3B, the shapes of barium sulfate and calcium carbonate are spherical or cubic-like shapes and are clearly not plate-like. Note that all the SEM photographs were taken using a tabletop microscope Miniscope (registered trademark) TM4000PlusII manufactured by Hitachi High-Technologies Corporation.

[0068] (Comparative Example 1) 40 parts of a plasticizer (3GO) was added to 100 parts of polyvinyl butyral to prepare an intermediate. To 100 parts of this intermediate, each component shown in Table 1 was added in the compounding amounts shown in Table 1 to obtain a resin composition. The obtained resin composition was sufficiently kneaded with a mixing roll at 120°C and then extruded with an extruder to obtain a sheet-like body. This sheet-like body is referred to as a vibration damping sheet.

[0069] (Comparative Examples 2 and 3 and Test Examples 1 to 20) 40 parts of a plasticizer (3GO) was added to 100 parts of polyvinyl butyral to prepare an intermediate. To 100 parts of this intermediate, each component (excluding the filler) shown in Tables 1 to 3 was added in the compounding amounts shown in the corresponding table to obtain a resin composition. To the obtained resin composition, the fillers shown in Tables 1 to 3 were added in the compounding amounts shown in the corresponding table, and after sufficiently kneading with a mixing roll at 120°C, it was extruded with an extruder to obtain a sheet-like body (vibration damping sheet).

[0070] (Evaluation Test) The following evaluations were performed in each test example. The results are shown in Tables 1 to 3.

[0071] (1) Adhesion and sticking to the kneader During the production of the vibration damping sheet, the adhesion or sticking of the raw materials to the kneader (i.e., the mixing roll) was visually observed and evaluated according to the following three criteria. 1: The adhesion or sticking to the kneader is large. 2: The adhesion or sticking to the kneader is moderate. 3: The adhesion or sticking to the kneader is small.

[0072] (2) Sheet formability (Whether sheet forming is possible) The sheet formability was evaluated according to the following three criteria by visually observing the state when the obtained vibration damping sheet was bent. 1: When the vibration damping sheet is bent, the sheet cracks. 2: When the vibration damping sheet is repeatedly bent, cracks appear in the sheet. 3: Even when the vibration damping sheet is repeatedly bent, no cracks appear in the sheet.

[0073] (3) Sheet specific gravity Samples measuring 30 mm in width and 30 mm in length were cut out from the obtained vibration damping sheet. Using these samples, the sheet specific gravity was measured by the water displacement method.

[0074] (4) Sheet thickness The thickness of the obtained vibration damping sheet was measured. The maximum thickness is shown in Tables 1 to 3.

[0075] (5) Vibration damping performance Samples measuring 30 mm in width and 300 mm in length were cut out from the obtained vibration damping sheet. The above samples cut out from the vibration damping sheet were adhered onto an SPCC steel plate with a thickness of 0.8 mm ± 0.06 mm, a width of 30 mm, and a length of 300 mm via double-sided tape. As the double-sided tape, “Double-sided tape 5782 for fixing interior members” manufactured by Sekisui Chemical Co., Ltd. was used. Using the obtained laminated samples, the loss factor and the resonance frequency were determined at 20°C according to the center excitation method of JIS K7391 (2008).

[0076]

Table 1

[0077]

Table 2

[0078]

Table 3

Industrial applicability

[0079] According to the present invention, it is possible to provide a vibration damping material that is extremely excellent in vibration damping performance, has good formability, workability, etc., and is also useful as a recycled product for an interlayer film for laminated glass, and a laminate including the vibration damping material. According to the present invention, it is also possible to provide a manufacturing method suitable for obtaining such a vibration damping material.

Claims

1. A polyvinyl acetal, a plasticizer, a tackifier, and a filler containing a plate-shaped inorganic filler, A vibration damping material characterized by the above.

2. The content of the plate-shaped inorganic filler is 10% by mass or more and 80% by mass or less with respect to 100% by mass of the total amount of the vibration damping material. The vibration damping material according to claim 1, characterized by the above.

3. The content of the filler is 48% by mass or more and 80% by mass or less with respect to 100% by mass of the total amount of the vibration damping material. The vibration damping material according to claim 1, characterized by the above.

4. The plate-shaped inorganic filler is a layered silicate. The vibration damping material according to claim 1, characterized by the above.

5. The plate-shaped inorganic filler is mica. The vibration damping material according to claim 1, characterized by the above.

6. Using a plate-shaped inorganic filler having a particle size of 100 mesh or less as a raw material. The vibration damping material according to claim 1, characterized by the above.

7. The polyvinyl acetal contains polyvinyl butyral, The plasticizer contains triethylene glycol di-2-ethylhexanoate. The vibration damping material according to claim 1, characterized by the above.

8. The loss factor with respect to each resonance frequency of the mechanical impedance measurement (MIM) measured in accordance with JIS K7391 (2008) is 0.05 or more at 20°C and 100 to 3000 Hz. The vibration damping material according to claim 1, characterized by the above.

9. Further, it contains a catcher agent that captures aldehydes. The vibration damping material according to claim 1, characterized in that...

10. The catcher agent is amorphous silica The vibration damping material according to claim 9, characterized in that...

11. It is sheet-shaped The vibration damping material according to any one of claims 1 to 10, characterized in that...

12. The thickness is 0.5 mm or more and 8 mm or less The vibration damping material according to claim 11, characterized in that...

13. A method for manufacturing the vibration damping material according to claim 11, comprising: adding a filler containing a plate-shaped inorganic filler to a resin composition containing polyvinyl acetal, a plasticizer, and a tackifier; and forming the mixture obtained by this step into a sheet. A method for manufacturing a vibration damping material, characterized in that...

14. The particle size of the plate-shaped inorganic filler is 100 mesh or less The method for manufacturing a vibration damping material according to claim 13, characterized in that...

15. On at least one main surface of the vibration damping material according to claim 11, at least one laminate selected from the group consisting of non-woven fabric, aluminum, polyethylene terephthalate, high-density polyethylene, and glass cloth laminate is laminated. A laminate, characterized in that...

Images