JP2023138264A - Resin composition for non-restriction type damping material, damping material, and damping laminate - Google Patents

Abstract

To provide a resin composition for a non-restriction type damping material which exhibits high damping properties by being used in a non-restriction type damping material, a damping material, and a damping laminate.SOLUTION: A resin composition for a non-restriction type damping material contains a chlorine-containing thermoplastic resin, chlorinated paraffin, and an inorganic filler, wherein the value of relaxation modulus G" under a condition of giving a maximum value of a loss tangent tanδ in a master curve at a reference temperature of 20°C, which is measured in a frequency dispersion mode of a shear type dynamic viscoelasticity apparatus, is 1×107 or more. A damping material contains the resin composition for the non-restriction type damping material, and a damping laminate 1 includes a base material 10, and a damping resin layer 12 containing the resin composition for the non-restriction type damping material.SELECTED DRAWING: None

Description

The present invention relates to a resin composition, a damping material, and a damping laminate for non-restrictive damping materials.

Conventionally, vibration damping materials and sound insulation materials have been used to reduce vibrations and noise generated in various fields such as houses, automobiles, airplanes, ships, and other vehicles, OA product housings, home appliance housings, and transportation equipment such as piping. It is used to block and absorb The damping material used is a polymeric material that utilizes viscoelasticity to efficiently convert and absorb vibrations into heat. As a vibration damping material that utilizes the viscoelasticity of a polymer material, a restraining type material is used, in which a viscoelastic layer is laminated on the vibration source, and a restraining layer with a high elastic modulus such as metal is further laminated on the surface not in contact with the vibration source. There is a swinging material.

In constrained vibration damping materials, the viscoelastic layer undergoes large shear deformation between the base material (vibration source) and the constraint layer, so high damping properties can be obtained by using a resin composition with a high loss tangent. I can do it. For example, Patent Document 1 describes a vibration damping material having a loss tangent exceeding 3 and a resin composition for a vibration damping material used for producing this damping material.

Patent No. 3306415

Since restraint-type damping materials have a restraint layer, their applicability to objects with curved surfaces is limited. Therefore, from the viewpoint of conformability to construction surfaces and curved surfaces, non-restrictive damping materials are used in which a viscoelastic layer is simply laminated on the vibration source. Furthermore, in vehicles and the like, non-restrictive damping materials are mainly used because they can be sprayed by robots.

In view of the above, the present invention provides a resin composition, a damping material, and a damping laminate for an unrestrained vibration damping material that exhibits high vibration damping properties when used in an unrestrained vibration damping material. It's about doing.

The present inventors have made extensive studies to solve the above problems. As a result, the maximum value of the loss tangent tan δ was determined in the master curve at 20°C, which contained a chlorine-containing thermoplastic resin, chlorinated paraffin, and inorganic filler, and was measured in the frequency dispersion mode of a shear-type dynamic viscoelasticity device. We have discovered that a high loss coefficient can be obtained by setting the value of the relaxation modulus G'' at a given frequency to 1×10 ⁷ or more, and have arrived at the present invention.
That is, the present invention provides the following [1] to [9].
[1] A resin composition for an unconstrained vibration damping material containing a chlorine-containing thermoplastic resin, a chlorinated paraffin, and an inorganic filler, which was measured by the frequency dispersion mode of a shear-type dynamic viscoelasticity device. A resin composition for an unconstrained vibration damping material, which has a relaxation modulus G'' of 1×10 ⁷ or more at a frequency that gives a maximum value of loss tangent tan δ in a master curve with a reference temperature of 20°C.
[2] The resin composition for an unrestricted vibration damping material according to [1], wherein the frequency that gives the maximum value of the loss tangent tan δ in the master curve is 0.5 Hz or more and 200 Hz or less.
[3] The total amount of the chlorinated paraffin based on 100 parts by weight of the chlorine-containing thermoplastic resin is 1,000 parts by weight or more and less than 5,000 parts by weight for a non-constrained vibration damping material according to [1] or [2]. Resin composition.
[4] The resin composition for an unrestricted vibration damping material according to any one of [1] to [3], wherein the inorganic filler is in the form of scales.
[5] The resin composition for a non-constrained vibration damping material according to any one of [1] to [4], wherein the inorganic filler is mica.
[6] The resin composition for an unrestricted vibration damping material according to any one of [1] to [5], wherein the inorganic filler has an aspect ratio of 10 or more.
[7] A vibration damping material comprising the resin composition for an unrestricted vibration damping material according to any one of [1] to [6].
[8] A base material, and a vibration damping resin layer disposed on at least one surface of the base material and comprising the resin composition for an unrestricted vibration damping material according to any one of [1] to [6]. A damping laminate comprising:
[9] The damping laminate according to [8], wherein the base material includes metal.

According to the present invention, it is possible to provide a resin composition, a damping material, and a damping laminate for an unrestrained vibration damping material that exhibits high vibration damping properties when used in an unrestrained vibration damping material. can.

FIG. 1 is a sectional view showing a damping laminate according to an embodiment of the present invention.

Hereinafter, embodiments of a resin composition for a non-restrictive damping material, a damping material, and a damping laminate of the present invention will be described in detail, but the following description is an example of an embodiment of the present invention. However, the present invention is not limited to these contents. In addition, in this specification, "~" representing a numerical range means a range that includes the numerical values before and after that range.

[Resin composition for non-constrained vibration damping material]
The resin composition for non-restrictive vibration damping materials of the present invention (hereinafter sometimes referred to as "resin composition for vibration damping materials") comprises a chlorine-containing thermoplastic resin, chlorinated paraffin, and an inorganic filler. A resin composition for an unconstrained vibration damping material containing a loss tangent tan δ in a master curve equivalent to 20°C corresponding to room temperature measured by a frequency dispersion dispersion mode of a shear type dynamic viscoelastic device. The value of the relaxation modulus G'' at the frequency that gives the maximum value is 1×10 ⁷ or more.

(Chlorine-containing thermoplastic resin)
The chlorine-containing thermoplastic resin used in the present invention contains chlorine as an element constituting the thermoplastic resin. The chlorine-containing thermoplastic resin is not particularly limited, but in order to effectively exhibit the effect of containing chlorine atoms, it is preferable that the weight difference between the thermoplastic resin and the constituent elements other than chlorine is large. As the chlorine-containing thermoplastic resin, resins composed of carbon, hydrogen, and chlorine are preferable, and specifically, vinyl chloride resins, copolymers of vinyl chloride resins and vinylidene chloride resins, and chlorinated polyethylene resins are preferable. , chlorinated vinyl chloride resins, copolymers of vinyl chloride resins and vinyl acetate resins, etc. Among these, chlorinated polyethylene resins are more preferred.

The degree of chlorination (chlorine content in all resin components) of the chlorine-containing thermoplastic resin is preferably 20 to 80% by weight, more preferably 25 to 75% by weight, and 30 to 70% by weight. It is even more preferable that there be. If the degree of chlorination of the chlorine-containing thermoplastic resin is 20% by weight or more, the crystals of the chlorine-containing thermoplastic resin will be difficult to grow, giving a large loss tangent tan δ, and the value of the relaxation modulus G'' will become large. , vibration damping performance is improved. In addition, when the degree of chlorination is 80% by weight or less, the intermolecular force does not become too strong, and it also gives a large loss tangent tan δ, so the value of the relaxation modulus G'' becomes large and the damping performance improves. do.

Further, the chlorine-containing thermoplastic resin may contain substituents other than chlorine, such as a cyano group, a hydroxyl group, an acetyl group, a methyl group, an ethyl group, bromine, and fluorine. The proportion of such substituents other than chlorine is preferably 5% by weight or less. If it exceeds 5% by weight, vibration damping performance may deteriorate.

(chlorinated paraffin)
The chlorinated paraffin used in the present invention is not particularly limited, but in order to obtain sufficient vibration damping properties, the degree of chlorination and the average number of carbon atoms are preferably within the following ranges.
The degree of chlorination of the chlorinated paraffin used in the present invention is preferably 20 to 90% by weight, more preferably 30 to 85% by weight, and even more preferably 40 to 80% by weight. When the degree of chlorination of the chlorinated paraffin is 20% by weight or more, it becomes difficult for crystals of the chlorine-containing thermoplastic resin to grow. Further, when the degree of chlorination is 90% by weight or less, the intermolecular force of the chlorine-containing thermoplastic resin does not become too strong, and the storage modulus G' becomes low. Therefore, by setting the degree of chlorination of the chlorinated paraffin within the above range, the value of the loss tangent tan δ increases and the damping performance improves.

Chlorinated paraffin with a carbon number of 13 or less is not desirable because it has safety problems, as it was designated as a Class 1 Specified Chemical Substance under the Chemical Substance Control Law in 2018. Furthermore, if the number of carbon atoms is too large, sufficient viscosity cannot be imparted by adding chlorinated paraffin. From the above, the average carbon number of the chlorinated paraffin used in the present invention is preferably 14 to 50, more preferably 14 to 28.
In addition, chlorinated paraffins with higher carbon numbers and chlorination degrees have a lower frequency that gives the maximum value of loss tangent tan δ (hereinafter also referred to as "tan δ peak frequency"). By using more than one type of chlorinated paraffin, the tan δ peak frequency can be controlled by adjusting their blending ratio.

The amount of chlorinated paraffin contained in the resin composition for vibration damping material of the present invention is preferably 1000 parts by weight or more and less than 5000 parts by weight, and 1000 parts by weight or more, based on 100 parts by weight of the chlorine-containing thermoplastic resin. More preferably, it is less than 2500 parts by weight. When the amount of chlorinated paraffin is 1000 parts by weight or more based on 100 parts by weight of the chlorine-containing thermoplastic resin, a large loss tangent tan δ can be provided, and vibration damping performance is improved. On the other hand, if the amount of chlorinated paraffin is less than 5,000 parts by weight based on 100 parts by weight of the chlorine-containing thermoplastic resin, the vibration damping material obtained and the vibration damping resin layer constituting the vibration damping laminate will have a mechanical Stronger and easier to hold shape.

(Inorganic filler)
The resin composition for vibration damping material of the present invention contains an inorganic filler. Inorganic fillers are used to impart a certain degree of hardness to resin compositions for vibration damping materials.
Inorganic fillers used in the present invention include, for example, talc, mica, silica, glass beads, graphite, alumina, titanium oxide, wollastonite, barium sulfate, calcium carbonate, glass fiber, cellulose fiber, carbon fiber, carbon nanotubes, Examples include carbon nanocoils, and among these, it is preferable to use mica.

The amount of inorganic filler contained in the resin composition for damping material of the present invention is preferably 500 to 5000 parts by weight, more preferably 1000 to 2500 parts by weight, based on 100 parts by weight of the chlorine-containing thermoplastic resin. When the amount of the inorganic filler is 500 parts by weight or more based on 100 parts by weight of the chlorine-containing thermoplastic resin, vibration damping properties can be improved by lowering the storage modulus G', and when the amount is 5000 parts by weight or less. It can be easily applied to the base material.

Although the shape of the inorganic filler used in the present invention is not particularly limited, it is preferably a scaly plate-like filler.
Moreover, it is preferable that the aspect ratio of the scale-like plate-like filler is 10 or more. The aspect ratio of an inorganic filler is calculated by measuring the maximum dimension (long axis) and minimum dimension (breadth axis) of the inorganic filler, and dividing the maximum dimension (long axis) by the minimum dimension (short axis) (long axis/breadth axis). Take the ratio. The aspect ratio of the inorganic filler is preferably the average aspect ratio of a plurality of inorganic fillers, and each of the 50 arbitrarily selected inorganic fillers is observed with an electron microscope or an optical microscope, and the major axis/minor axis of each inorganic filler is determined. It can be determined by calculating the average value of . In addition, in the case of a scale-like inorganic filler, the thickness of the inorganic filler becomes the short axis.

(Other additive ingredients)
The resin composition for a vibration damping material of the present invention may contain other additive components as necessary within a range that does not impair the object of the present invention. As other additive components, a rosin compound or the like may be included in order to impart adhesiveness to the vibration damping material. As the rosin compound, rosin metal salts, rosin esters, etc. can be used.

Furthermore, a tin-based stabilizer can be included as a thermal stabilizer during molding of the resin composition for vibration damping material. The tin-based stabilizer is not particularly limited, and includes dialkyltin malate, dialkyltin bis(monoalkylmalate), dibutyltin maleate polymer, dialkyltin laurate, dialkyltin mercapto, dialkyltin bis(mercapto fatty acid ester), dialkyltin Examples include sulfide and dioctyltin malate polymers. These may be used alone or in combination of two or more.

In addition, as necessary, plasticizers, fillers, lubricants, anti-shrinkage agents, crystal nucleating agents, colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, anti-aging agents, reinforcing agents, flame retardants, etc. Auxiliary agents, antistatic agents, surfactants, vulcanizing agents, surface treatment agents, and the like can be included.

(Physical property values of resin composition for vibration damping material)
[Relaxation modulus]
The resin composition for a vibration damping material of the present invention exhibits relaxation at a frequency that gives the maximum value of loss tangent tan δ in a master curve with a reference temperature of 20°C, as measured by the frequency dispersion mode of a shear type dynamic viscoelasticity device. The value of elastic modulus G'' is 1×10 ⁷ or more. Since it is known that the loss coefficient has a correlation with the relaxation modulus G'' of the resin composition for damping materials, the relaxation modulus G'' at the frequency that gives the maximum value of the loss tangent tan δ is 1× By setting it as 10 ^<7> or more, the resin composition for vibration damping materials of this invention can exhibit the outstanding vibration damping property. The relaxation modulus G'' is preferably 2×10 ⁷ Pa or more. There is no particular restriction on the upper limit, but if it is too high relative to the elastic modulus of the base material, deformation due to vibration will be suppressed, so it is usually preferably 5×10 ¹⁰ Pa or less.

[Frequency that gives the maximum value of loss tangent tanδ]
The present inventors have discovered that in the resin composition for an unconstrained damping material of the present invention, the frequency at which the loss coefficient has a maximum value is about 100 times the tan δ peak frequency in the master curve of the frequency dispersion of viscoelasticity. I found that.
From this, the resin composition for damping material of the present invention gives the maximum value of the loss tangent tan δ in the master curve at a reference temperature of 20°C, as measured by the frequency dispersion mode of the shear type dynamic viscoelasticity device. The frequency (tan δ peak frequency) is preferably within the range of 0.5 Hz or more and 200 Hz or less, and more preferably the tan δ peak frequency is within the range of 0.5 Hz or more and 100 Hz or less. By setting it within the above range, it is possible to provide the maximum value of the loss coefficient between 50 Hz and 20,000 Hz, which is a frequency 100 times the tan δ peak frequency, and more preferably between 50 Hz and 10,000 Hz. By setting the maximum value of the loss coefficient within the above range, the resin composition for a vibration damping material of the present invention can exhibit excellent vibration damping properties. As a method for obtaining the master curve, the shift factor may be determined by the WLF equation, or may be obtained by curve fitting using a control program of the measuring device.

[Vibration damping material]
The damping material of the present invention can be obtained by shaping the above resin composition for damping material. The shape of the damping material is not particularly limited, and may be sheet-like, plate-like, rod-like, or block-like, but a sheet-like damping sheet is preferred. Note that the term "sheet" is not limited to a strict meaning based on thickness, and includes thin sheets usually called "films" and thick sheets called "plates." The thickness of the vibration damping sheet is not particularly limited, but if it is too thin, the damping effect may be reduced, and if it is too thick, it may be inconvenient to handle when applied to the source of vibration. Yes, preferably 0.05 to 50 mm.

[Vibration damping laminate]
Next, a damping laminate according to an embodiment of the present invention will be described. FIG. 1 is a sectional view showing a damping laminate according to an embodiment of the present invention.
As shown in FIG. 1, a damping laminate 1 according to an embodiment of the present invention includes a base material 10 and a damping resin layer 12 disposed on one surface of the base material 10. The vibration damping resin layer 12 is configured to include the resin composition for the vibration damping material.

The thickness of the vibration-damping laminate 1 may be arbitrary, but if it is too thin, it will not be possible to obtain sufficient vibration-damping properties, and if it is too thick, it will be heavy and workability will be poor, so it is 1 mm to 50 mm. It is preferably from 2 mm to 40 mm, and even more preferably from 3 mm to 30 mm.

(Base material)
The base material 10 is not particularly limited as long as it is a material having a high elastic modulus. Examples of the base material 10 include metal materials such as lead, steel (including stainless steel), copper, and aluminum; and inorganic materials such as concrete, gypsum board, marble, slate, sand, and glass. These may be used alone or in combination of two or more.

The thickness of the base material 10 may be arbitrary, but if it is too thin, it will not be possible to obtain sufficient vibration damping properties, and if it is too thick, it will be heavy and workability will be poor, so it is preferably between 50 μm and 50 mm. The thickness is preferably 100 μm to 40 mm, and even more preferably 200 μm to 30 mm.

(Vibration damping resin layer)
The damping resin layer 12 is formed from the resin composition for damping material described above. The method for forming the damping resin layer 12 is not particularly limited, and may be any general sheet forming method such as extrusion, calendaring, or solvent casting, but it may be a multi-layer method that allows continuous coextrusion production. An extrusion molding method using a manifold method or a feedblock method is preferred from the viewpoint of productivity. The damping resin layer 12 may be formed by applying a resin composition for damping material to the base material 10, or by disposing the base material 10 after molding the resin composition for damping material. Good too.

The thickness of the damping resin layer 12 is preferably 0.5 to 5 times the thickness of the base material 10, and preferably 1 to 3 times the thickness of the base material 10. When the thickness of the damping resin layer 12 is within the above range, damping properties can be exhibited, and vibrations can be well absorbed or reduced. Note that the thickness of the damping resin layer 12 does not need to be the same within the damping laminate 1, and may have different thicknesses within the damping laminate 1 as long as it is within the above range. good.

Although the damping laminate 1 of the embodiment shown in FIG. 1 has the damping resin layer 12 disposed only on one surface of the base material 10, the present invention is not limited to this. It is also possible to have a structure in which damping resin layers 12 are disposed on both surfaces of 10.

<How to use vibration damping laminate>
How to use the damping laminate 1 will be explained. The damping laminate 1 is used by being attached and integrated with a target member (hereinafter referred to as "construction member") using a viscoelastic resin. Since the damping laminate of the present invention is used as a non-restrictive damping material, it is preferable that the damping resin layer 12 be on the surface opposite to the construction member. That is, when the damping resin layer 12 is arranged on one surface of the base material 10, the base material 10 and the construction member are attached and used. When the damping resin layer 12 is arranged on both surfaces of the base material 10, the damping resin layer 12 and the construction member are attached and used. Construction components are not particularly limited, and include, for example, components of transportation equipment such as automobiles, railways, ships, and aircraft, components of buildings (e.g., exterior wall members, interior components, ceiling members, etc.), industrial machinery, etc. Examples include components of industrial equipment, components of OA equipment such as computers, and components of home appliances such as washing machines and refrigerators.

Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited by these Examples.
In addition, in the examples and comparative examples, the following materials and measurement methods were used.

[Chlorine-containing thermoplastic resin]
Chlorinated polyethylene (manufactured by Showa Denko K.K., product number "SDM-451B", (chlorine content: 45% by weight)) was used as the chlorine-containing thermoplastic resin.
[Chlorinated paraffin]
As chlorinated paraffin, the product name "Toyoparax A50" (manufactured by Tosoh Corporation (average carbon number 25, chlorine content 50%)), the product name "Empara 70" (manufactured by Ajinomoto Fine Techno Co., Ltd. (average carbon number 26, chlorine content 50%)), (content: 71.5% by weight)) were used alone or in combination.
[Tackifier]
As the tackifier, rosin ester (manufactured by Arakawa Chemical Industry Co., Ltd., product number "KE-359") was used.
[Stabilizer]
As the stabilizer, a tin-based stabilizer (manufactured by Nitto Kasei Co., Ltd., product number "TVS #8570") was used.
[Inorganic filler]
The inorganic fillers listed in Table 1 were used.

[Resin composition]
Each material was weighed in a PE cup according to the compounding ratio shown in Tables 2 and 3, and kneaded in a roll machine at 140°C to form damping materials for Examples 1 to 10 and Comparative Examples 1 and 2. A resin composition was obtained.

[Measuring method]
(Viscoelastic evaluation)
The resin compositions for vibration damping materials of Examples 1 to 10 and Comparative Examples 1 and 2 were sandwiched between polyethylene terephthalate whose surfaces had been subjected to mold release treatment, and molded into a sheet-like resin composition with a thickness of 1.5 mm by hot pressing. did. The storage modulus (G'), relaxation modulus (G''), and loss tangent (tan δ) of this sheet-like resin composition were measured at a temperature of 10°C using a viscoelasticity meter (MCR102 manufactured by Acton Paar). Measurements were made at 20°C and 30°C, at a frequency of 1 to 100Hz, and at a strain of 0.05%. Based on the measurement results for 20°C, a master curve for the reference temperature of 20°C was obtained by shifting the time axis of the measurement results for 10°C and 30°C so as to obtain a continuous curve.
The frequency at which the loss tangent (tan δ) becomes maximum in the master curve was determined, and the maximum values of the storage modulus (G'), relaxation modulus (G''), and loss tangent (tan δ) at that frequency were determined.

(loss factor measurement)
A sheet-like resin composition of the same type was placed on a steel plate (Fe base material) or aluminum plate (AL base material) with a width of 10 mm, a length of 250 mm, and a thickness of 1.5 mm that had been heated to 70°C, and was then heated by hand through a release paper. A test piece for evaluating the loss factor was prepared by pressing it lightly. Based on JIS K7391, the loss coefficient was calculated from the first-order resonance frequency to the fifth-order resonance frequency using the central vibration method.

As is clear from the description in Table 2, the loss coefficient evaluation test pieces (damping laminates) obtained from the resin compositions for damping materials of Examples 1 to 8 have a maximum loss tangent tan δ. The value of relaxation modulus G'' at the ^frequency giving It showed a high loss coefficient and good vibration damping properties.
In particular, Examples 1 to 5 using scale-like fillers showed higher loss coefficients.

As shown in Table 3, when chlorinated paraffins with different carbon numbers and degrees of chlorination are combined, the frequency that gives the maximum value of the loss tangent tan δ of the resin composition can be determined depending on the blending ratio of each chlorinated paraffin. The loss coefficient is maximum at a frequency that is approximately 100 times the frequency that gives the maximum value of the loss tangent tan δ (first-order resonance in Example 9, second-order resonance in Example 10, and fourth-order resonance in Example 11). It was shown that From this, it was confirmed that if the frequency that gives the maximum value of the loss tangent tan δ is 0.5 Hz or more and 200 Hz or less, the maximum loss coefficient is in the audible range from 50 Hz to 20,000 Hz, and it is desirable as a damping material.

1: Vibration damping laminate 10: Base material 12: Vibration damping resin layer

Claims (9)

A resin composition for an unrestricted vibration damping material comprising a chlorine-containing thermoplastic resin, a chlorinated paraffin, and an inorganic filler,
In a master curve with a reference temperature of 20°C, measured using the frequency dispersion mode of a shear-type dynamic viscoelasticity device, the value of the relaxation modulus G'' at the frequency that gives the maximum value of the loss tangent tan δ is 1 × 10 ⁷ or more A resin composition for non-restrictive vibration damping material. The resin composition for an unconstrained vibration damping material according to claim 1, wherein a frequency giving a maximum value of the loss tangent tan δ in the master curve is 0.5 Hz or more and 200 Hz or less. The resin composition for an unconstrained vibration damping material according to claim 1 or 2, wherein the total amount of the chlorinated paraffin based on 100 parts by weight of the chlorine-containing thermoplastic resin is 1000 parts by weight or more and less than 5000 parts by weight. The resin composition for a non-constrained vibration damping material according to claim 1 or 2, wherein the inorganic filler is in the form of scales. The resin composition for a non-restricted vibration damping material according to claim 1 or 2, wherein the inorganic filler is mica. The resin composition for an unconstrained vibration damping material according to claim 1 or 2, wherein the inorganic filler has an aspect ratio of 10 or more. A vibration damping material comprising the resin composition for an unrestricted vibration damping material according to claim 1 or 2. A damping laminate comprising a base material and a damping resin layer disposed on at least one surface of the base material and containing the resin composition for an unconstrained damping material according to claim 1 or 2. body. The damping laminate according to claim 8, wherein the base material contains metal.