JP2023129886A - Resin composition for damping material, and damping material - Google Patents

Abstract

To provide a resin composition for damping materials, designed to produce a damping material with excellent vibration absorption performance, and to provide such a damping material.SOLUTION: A resin composition for damping materials is provided, including a thermoplastic resin with 20-65 wt.% of chlorine groups present on its side chain, and liquid chlorinated paraffin with an HSP distance from the thermoplastic resin of 2.0-8.0, a viscosity (20°C) of 1.0-5000 poise, and an average carbon atom count of 10-50, and a chlorine content of 30-70 wt.%. Relative to 100 pts.wt. of the thermoplastic resin, the liquid chlorinated paraffin is 200-800 pts.wt. Also provided is a damping material that includes the resin composition.SELECTED DRAWING: None

Description

The present invention relates to a resin composition for a vibration damping material and a vibration damping material.

Conventionally, it has occurred in residential structures such as houses, condominiums, and office buildings, various structures such as expressways, elevated bridges, and railway tracks, various vehicles such as automobiles, railway cars, and ships, and equipment such as home appliances and OA equipment. Vibration damping sheets are used to reduce vibration and noise.

The loss tangent (tan δ = E''/E'), which is obtained by dividing the loss elastic modulus (E'') by the storage elastic modulus (E') of the material, is generally used as an index of damping performance, and the loss tangent is large. The material has excellent vibration absorption properties. When this value exceeds 1, it is said to be an excellent vibration damping material, but further improvement in vibration damping properties is desired. As an excellent vibration damping material, for example, Patent Document 1 describes a high damping resin composition consisting of 100 parts by weight of a chlorine-containing thermoplastic resin and 30, 50, or 100 parts by weight of liquid chlorinated paraffin having an average carbon number of 20 to 50. is disclosed.

Japanese Patent Application Publication No. 11-80562

In recent years, there has been a desire for further improvement in damping properties, and materials with a loss tangent of more than 4 are desired. However, the high attenuation resin composition described in Patent Document 1 had a loss tangent value of 1.6 at room temperature (20° C.), which never exceeded 4.

In view of the above points, an object of the present invention is to create a resin composition for a vibration damping material to obtain a vibration damping material exhibiting excellent vibration damping and absorbing properties such that the loss tangent value exceeds 4 at room temperature (20°C). The objective is to provide products and vibration damping materials.

The present inventors have made extensive studies to solve the above problems. As a result, we discovered that the above problems can be solved by using a thermoplastic resin and liquid chlorinated paraffin that meet specific conditions, and by blending the thermoplastic resin and liquid chlorinated paraffin in a specific ratio, We have arrived at the present invention.
That is, the present invention provides the following [1] to [6].
[1] A thermoplastic resin having 20 to 65% by weight of chlorine groups in the side chain, and an HSP distance of 2.0 to 8.0 and a viscosity (20°C) of 1.0 to 5000 poise. , a liquid chlorinated paraffin having an average carbon number of 10 to 50 and containing a chlorinated amount of 30 to 70% by weight; Resin composition for vibration damping material containing ~800 parts by weight.
[2] The resin composition for a vibration damping material according to [1], wherein the thermoplastic resin has a chlorine group content of 35 to 50% by weight.
[3] The liquid chlorinated paraffin has an HSP distance of 3.0 to 6.0 with respect to the thermoplastic resin, a viscosity (at 20°C) of 500 to 3000 poise, an average carbon number of 12 to 28, and The resin composition for vibration damping material according to [1] or [2], which contains 45 to 65% by weight of silica.
[4] The resin composition for a vibration damping material according to any one of [1] to [3], which contains 450 to 700 parts by weight of the liquid chlorinated paraffin based on 100 parts by weight of the thermoplastic resin.
[5] A vibration damping material comprising the resin composition for vibration damping materials according to any one of [1] to [4].
[6] The damping material according to [5], wherein the damping material is a damping sheet.

According to the present invention, a vibration damping material capable of exhibiting excellent vibration damping and absorbing properties with a loss tangent (hereinafter sometimes referred to as "tan δ") value exceeding 4 can be obtained. A resin composition for materials and a vibration damping material can be provided.

Hereinafter, embodiments of the resin composition for a vibration damping material and the vibration damping material of the present invention will be described in detail. Not limited. 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 vibration damping material]
The damping material resin composition of the present invention has a thermoplastic resin having 20 to 65% by weight of chlorine groups in the side chain, an HSP distance of 2.0 to 8.0, and a viscosity (20°C). liquid chlorinated paraffin having an average carbon number of 1.0 to 5000 poise, an average carbon number of 10 to 50, and a chlorinated amount of 30 to 70% by weight. Contains 200 to 800 parts by weight of chlorinated paraffin.

(Thermoplastic resin)
The thermoplastic resin used in the present invention is not particularly limited as long as it is a thermoplastic resin having 20 to 65% by weight of chlorine groups in its side chains. When the amount of chlorine groups in the thermoplastic resin is less than 20% by weight, the crystals of the thermoplastic resin tend to grow, resulting in an increase in the storage modulus, a decrease in the loss tangent value, and a decrease in vibration damping performance. . If the amount of chlorine groups exceeds 65% by weight, the intermolecular force becomes too strong, the storage modulus increases, the loss tangent value decreases, and the damping performance deteriorates. The amount of chlorine groups in the thermoplastic resin is preferably 35 to 50% by weight.

Furthermore, the 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.

Examples of the thermoplastic resin used in the present invention include chlorinated polyethylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, and the like. Preferred thermoplastic resins are amorphous ones that have a low storage modulus and therefore a large value of loss tangent, and chlorinated polyethylene is preferred.

(liquid chlorinated paraffin)
The liquid chlorinated paraffin used in the present invention has an HSP distance from the thermoplastic resin of 2.0 to 8.0, a viscosity (at 20°C) of 1.0 to 5000 poise, and an average carbon number of 10 to 50. , containing 30 to 70% by weight of chlorination. Each condition will be explained below.

The liquid chlorinated paraffin of the present invention has an HSP distance of 2.0 to 8.0 with respect to the thermoplastic resin. The lower the HSP distance between the liquid chlorinated paraffin and the thermoplastic resin, the higher the compatibility with the thermoplastic resin. ) will be higher. On the other hand, as the HSP distance with the thermoplastic resin increases, the compatibility with the thermoplastic resin decreases, and as a result, the free rotational movement of the thermoplastic resin is inhibited, and the damping performance decreases. Therefore, the HSP distance with the thermoplastic resin is 2.0 to 8.0, preferably 3.0 to 6.0, more preferably 3.0 to 4.2, and 3.2 to 4.0. More preferred.

Note that the HSP (Hansen solubility parameters) distance is calculated by the following formula (1), focusing on two specific molecules (solvent and solute: in the present invention, liquid chlorinated paraffin and thermoplastic resin). It is defined as a solubility index to determine whether two molecules are compatible.
HSP distance = {4 (δD1-δD2) ² + (δP1-δP2) ² + (δH1-δH2) ² } ^0.5 ...(1)
Here, in formula (1), δD1, δP1, δH1, δD2, δP2, and δH2 are Hansen solubility parameters of two specific molecules, and the solubility is expressed as δD, the polar term as δP, and the hydrogen bond term as δD. is expressed in the three-dimensional space of δH. The dispersion term δD represents the effect due to dispersion force, the polar term δP represents the effect due to dipole-dipole force, and the hydrogen bond term δH represents the effect due to hydrogen bond force.
The HSP of a particular substance can be determined by performing a solubility test in which a sample of the substance is dissolved in a number of different solvents for which Hansen solubility parameters have been established.

The liquid chlorinated paraffin of the present invention has a viscosity (20° C.) of 1.0 to 5000 poise. If the viscosity of the liquid chlorinated paraffin is too low, the peak of the loss tangent will shift to the low temperature side, and if it is too high, the peak of the loss tangent will shift to the high temperature side, resulting in poor damping performance at room temperature (20° C.). Therefore, the viscosity (at 20° C.) is 1.0 to 5000 poise, preferably 500 to 3000 poise, and more preferably 1000 to 2500 poise.

The liquid chlorinated paraffin of the present invention has an average carbon number of 10 to 50. When the proportion of liquid chlorinated paraffin in the resin composition for vibration damping materials is constant, the lower the average carbon number, the larger the molar amount of liquid chlorinated paraffin, and as a result, the crystals of the thermoplastic resin grow. damping performance (peak value of loss tangent) becomes higher. However, as the average carbon number decreases, liquid chlorinated paraffin tends to bleed out, resulting in a decrease in vibration damping performance. Furthermore, if the average number of carbon atoms becomes large, sufficient damping properties may not be exhibited. Therefore, the average number of carbon atoms is 10 to 50, preferably 12 to 28.

The liquid chlorinated paraffin of the present invention has a chlorinated content of 30 to 70% by weight. If the amount of chlorination in the liquid chlorinated paraffin is too small, crystals of the thermoplastic resin will tend to grow. Furthermore, if the amount of chlorination is too large, the intermolecular force of the thermoplastic resin becomes too strong, and the storage modulus (E') of the damping material increases. Therefore, if it is too little or too much, the value of tan δ becomes small, so the amount of chlorination is limited to 30 to 70% by weight, preferably 45 to 65% by weight, and more preferably 48 to 62% by weight. .

The liquid chlorinated paraffin of the present invention has an HSP distance from the thermoplastic resin of 3.0 to 6.0, a viscosity (at 20°C) of 500 to 3000 poise, an average carbon number of 12 to 28, and a chlorinated amount. It is preferable to contain 45 to 65% by weight of. In addition, liquid chlorinated paraffin has an HSP distance of 3.2 to 4.0 with the thermoplastic resin, a viscosity (20°C) of 1000 to 2500 poise, an average carbon number of 12 to 28, and a low chlorination amount. More preferably, the content is 48 to 62% by weight.

(Blending ratio of thermoplastic resin and liquid chlorinated paraffin)
The liquid chlorinated paraffin of the present invention is contained in an amount of 200 to 800 parts by weight based on 100 parts by weight of the thermoplastic resin. If the amount of liquid chlorinated paraffin is too small, crystals of the thermoplastic resin will tend to grow. On the other hand, if the amount of liquid chlorinated paraffin is too large, the mechanical strength of the resulting damping material tends to decrease, and shape retention may become difficult. Therefore, the amount of liquid chlorinated paraffin is 200 to 800 parts by weight, preferably 400 to 800 parts by weight, based on 100 parts by weight of the thermoplastic resin.

(Other additive ingredients)
The resin composition for vibration damping materials 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, when transparency is required for the vibration damping material, a rosin compound can be included. As the rosin compound, rosin metal salts, rosin esters, etc. can be used.

Moreover, 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.

[Vibration damping material]
The vibration damping material of the present invention can be obtained by shaping the resin composition for vibration damping materials of the present invention. 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.

Further, the loss tangent (tan δ) of the damping material is 4 or more at 20°C. By setting it as this range, the vibration damping performance will be excellent in the normal usage environment of the vibration damping material.

(effect)
The resin composition for vibration damping materials of the present invention consists of a thermoplastic resin having specific conditions and a liquid chlorinated paraffin having specific conditions, and the liquid chlorinated paraffin is added to the chlorine-containing thermoplastic resin in a specific ratio. The vibration damping material obtained from this resin composition for vibration damping materials exhibits excellent vibration damping and absorbing properties with a loss tangent value exceeding 4.

Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited by these Examples.

[Measuring method]
The method for measuring each physical property in this specification is as follows.
<Loss tangent>
The loss tangent of the sheet-shaped damping material was measured using a viscoelasticity measuring instrument ("Rheolograph" manufactured by Toyo Seiki Seisakusho Co., Ltd.) at a temperature of -40 to 40°C and a frequency of 50 Hz. The loss tangent was calculated from the longitudinal elastic modulus (E', E'') by a conventional method, and the loss tangent at 20°C, the peak value of the loss tangent, and the temperature of the peak value were determined.

<Compatibility evaluation>
The chlorinated polyethylene and liquid chlorinated paraffin used in Examples and Comparative Examples were dissolved in approximately 30 types of solvents selected from the Master database whose HSP: Hansen solubility parameters (δDi, δPi, δHi) have been confirmed. Solubility was evaluated using the computer software Hansen Solubility Parameters in Practice (HSPiP) Ver. 4.0.05 was used to estimate polyethylene and liquid chlorinated paraffin HSP. Subsequently, using each of the estimated HSPs, an HSP distance serving as an index was calculated using the following formula (1).
HSP distance = {4 (δD1-δD2) ² + (δP1-δP2) ² + (δH1-δH2) ² } ^0.5 ...(1)

[Example 1]
(Preparation of vibration damping sheet)
100 parts by weight of chlorinated polyethylene (manufactured by Showa Denko Co., Ltd., product number "SDM-451B", chlorine content 45% by weight), liquid chlorinated paraffin 1 (manufactured by Tosoh Corporation, product name "Toyoparax A50", viscosity (20 ° C. ) 1500 poise, chlorine content 50% by weight, average carbon number 25) 517 parts by weight, 100 parts by weight of rosin ester (manufactured by Arakawa Chemical Co., Ltd., product number "KE-359"), and tin-based stabilizer (Nitto Kasei Co., Ltd.) (product number: TVS #8570)) were kneaded in a roll machine and pressed at 150°C to obtain a vibration damping sheet with a thickness of 1000 μm. Table 1 shows the evaluation results of the obtained damping sheet.

[Example 2]
A damping sheet was produced in the same manner as in Example 1, except that the amount of liquid chlorinated paraffin 1 was 670 parts by weight based on 100 parts by weight of chlorinated polyethylene. Table 1 shows the evaluation results of the obtained damping sheet.

[Example 3]
Instead of liquid chlorinated paraffin 1 in Example 1, liquid chlorinated paraffin 2 (manufactured by Tosoh Corporation, trade name "Toyoparax 160", viscosity (20°C) 2000 poise, chlorine content 60% by weight, average carbon number) A damping sheet was produced in the same manner as in Example 1, except that Example 15) was used. Table 1 shows the evaluation results of the obtained damping sheet.

[Example 4]
A damping sheet was produced in the same manner as in Example 3, except that the amount of liquid chlorinated paraffin 2 was 670 parts by weight based on 100 parts by weight of chlorinated polyethylene. Table 1 shows the evaluation results of the obtained damping sheet.

[Comparative example 1]
Instead of liquid chlorinated paraffin 1 in Example 1, liquid chlorinated paraffin 3 (manufactured by Tosoh Corporation, trade name "Toyoparax 150", viscosity (20°C) 20 poise, chlorine content 50% by weight, average carbon number) A damping sheet was produced in the same manner as in Example 1, except that Example 15) was used. Table 1 shows the evaluation results of the obtained damping sheet.

[Comparative example 2]
Instead of liquid chlorinated paraffin 1 in Example 1, liquid chlorinated paraffin 4 (manufactured by Tosoh Corporation, trade name "Toyoparax 145", viscosity (20°C) 4.0 poise, chlorine content 45% by weight, average A damping sheet was produced in the same manner as in Example 1 except that a material having 15 carbon atoms was used. Table 1 shows the evaluation results of the obtained damping sheet.

As is clear from Table 1, the damping sheets produced in Examples 1 to 4 had excellent damping and absorbing properties with loss tangents exceeding 4 at 20°C. Furthermore, the damping sheets of Examples 1 to 4 exhibited peak values of loss tangent at around 20° C. or room temperature. The damping sheets of Comparative Examples 1 and 2 had loss tangents of 1.1 and 1.2 at 20° C., respectively, and were unable to obtain sufficient damping and absorbing properties.

Claims (6)

A thermoplastic resin having 20 to 65% by weight of chlorine groups in its side chains;
The HSP distance with the thermoplastic resin is 2.0 to 8.0, the viscosity (20 ° C.) is 1.0 to 5000 poise, the average carbon number is 10 to 50, and the amount of chlorination is 30 to 70% by weight. liquid chlorinated paraffin,
including;
A resin composition for a vibration damping material, comprising 200 to 800 parts by weight of the liquid chlorinated paraffin based on 100 parts by weight of the thermoplastic resin. The resin composition for a vibration damping material according to claim 1, wherein the content of chlorine groups in the thermoplastic resin is 35 to 50% by weight. The liquid chlorinated paraffin has an HSP distance of 3.0 to 6.0 with respect to the thermoplastic resin, a viscosity (at 20°C) of 500 to 3000 poise, an average carbon number of 12 to 28, and a chlorinated amount of 3.0 to 6.0. The resin composition for vibration damping material according to claim 1 or 2, containing 45 to 65% by weight. The resin composition for a vibration damping material according to any one of claims 1 to 3, comprising 450 to 700 parts by weight of the liquid chlorinated paraffin based on 100 parts by weight of the thermoplastic resin. A vibration damping material comprising the resin composition for a vibration damping material according to any one of claims 1 to 4. The damping material according to claim 5, wherein the damping material is a damping sheet.