RU2067988C1 - Thermoplastic material intended for sound absorption and vibration-proof insulation - Google Patents

Abstract

FIELD: sound absorption and vibration-proof insulation. SUBSTANCE: proposed material contains (mass parts): polyethylene (content of chlorine in it being 20-95 %) 200-225, softening agent 425-850 and finely dispersed filler 4000-4500. Mentioned above softening agent is chosen of aromatic oil, semiaromatic oil and dodecyl isophthalate. EFFECT: improves quality of desired product. 2 tbl

Description

 The subject of the invention is a thermoplastic material that has the properties of sound absorption and vibration isolation and can be used, in particular, in the bulkhead between the engine and the interior of the car (for example, with a body type "sedan"), and generally in other places of cars, trains, planes and etc. as well as in walls, floors, ceilings, metal cladding of buildings and in household appliances, and industrial machines (in the latter two cases for vibration isolation).

 Known thermoplastic material described in / 1 /, including chlorinated polyethylene with a chlorine content of 20-95% oil containing up to 15% unsaturated compounds (ASTM D2007), a large number of aromatic compounds and a finely divided filler / 1 /.

A thermoplastic material suitable for use in a bulkhead between the engine and the interior of a vehicle must have:
excellent acoustic characteristics (sound barrier and anti-vibration);
good indicators reflecting a property known as tarnishing (which is the result of the release of volatile substances deposited on cold surfaces, in particular on glass surfaces such as the surface of car windows, obstructing the view through them);
high flexibility;
the ability to easily engage with other components and with the walls of the car or its compartment;
high stability and resistance at extreme temperatures;
the optimal values of Young's modulus, which is the modulus of elasticity in compression, and the mechanical loss coefficient (known as the tangent delta), which measure the characteristics of energy dissipation by a material);
resistance to aging and high leafing properties;
the ability to easily laminate and process, and
ability to process economically.

In the study of the material and the products obtained from it in accordance with the patent / 1 /, the applicant found that the desired goal can be achieved by using as a softener a compound selected from the group - aromatic oil with the following characteristics:
Specific gravity at 15 ^o C 0.98-1.00
Viscosity ^o E at 50 ^o C 180-260
Flash point in open crucible, ^o C 270 minimum
Pour point, ^o C +15 max
Aniline point, ^o C 75 max
Water, vol. 0.1 max
or semi-aromatic oil with the following characteristics:
Specific Gravity at 15 ^o C 0.92-0.94
Viscosity, ^o E at 50 ^o C 65-80
Flash point in open crucible, ^o C 270 minimum
Pour point, ^o C -9 max
Aniline point, ^o C 102
Color 7 maximum
The number of neutralization, mg KOH / g 0,05
Water, vol. 0.1 maximum
Saturation, weight. 46
Aromatic, weight. 43.5
Polar, weight. 10.5
Asphaltenes 0
Paraffin hydrocarbons, weight. 63
Naphthenic hydrocarbons, weight. 22
Aromatic hydrocarbons, weight. fifteen
Refractive index n $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ 1,517
sulfur, weight. 2,8
or diisododecyl phthalate with the following characteristics:
Specific gravity at 20 ^o C, g / cm ³ 0.966-0.970
at 25 ^o C 0.963-0.967
Viscosity at 20 ^o C OST 156
Pour point, ^o C -47
Refractive index n $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ 1,482-1,488
Flash point (open crucible Pens Ky Martens /, ^o C> 200
Solubility in water at 20 ^o C, weight. 0.01
Volatility, weight loss after 24 hours at 180 ^o C 7.1
Acid number mg KOH / g 0.07 maximum
The content of esters, weight / weight 99 minimum
Free alcohol content, weight / weight 0.1 maximum
Water content, weight / weight 0.1 maximum
Aniline point, ^o C <25
in the following ratio of components of the material, parts by weight

Chlorinated Polyethylene 200-225
Specified Softener 425-850
Fine filler 4000-4500
The test methods that were used to measure quantities characterizing the properties of the material:
a) the tarnishing resulting from the release of volatile substances and the material that is the subject of the invention, and their subsequent concentration on cold surfaces, mainly on glass surfaces (in particular on the surfaces of the windows of the passenger compartment), should be as small as possible. Moreover, the precipitation of volatile materials must have a very low opacity so that they do not impede the view through the glass, in particular through the windshield of the car. This property was measured according to the methods set forth in 1PN75201, methods recommended by SAABSCANIA 1082 and those used in Ford laboratories, the test method (EUBN 1-1 "/;
b) the flexibility of the material is measured by static deformation, which is defined as the deformation observed in the test sample under the influence of the actual weight, when part of the sample lies on the table and the other part hangs from the table. It has been experimentally shown that sheets made of very flexible materials have more barriers than sheets made of hard materials;
c) the behavior at low temperatures is studied using the fragility of the obtained material. This parameter is measured by dropping a 500 g steel ball onto a material from a height of 30 cm and observing cracks appearing on the surface of the test material;
d) resistance and stability at high temperatures are measured by placing the material on a slope with an angle of 75 ^o and holding for five hours at a temperature of 80 ^o C followed by observation, the material has flowed or not. It was found that the products obtained in accordance with this invention are not subject to change or transformation;
e) Young's modulus, which is the modulus of static elasticity in compression, is measured using a device called the Metravib at an offset of ± 60 units. The tangent delta (or tanδ) is the coefficient of mechanical losses and expresses the characteristics of energy dissipation by a material. This parameter is measured indirectly when measuring Young's modulus. A smaller value of the modulus E (the real part of the Young's modulus) corresponds to a greater elasticity of the material, and a larger value of tanδ corresponds to a greater energy dissipation by the material.

 The invention is illustrated by the following examples.

 Several thermoplastic materials were prepared, which are assigned numbers from one to five, the material of example 1 corresponds to the typical material prepared according to / V /, the materials prepared according to examples 2-5 correspond to this invention.

 According to the above test methods, measurements were made of quantities characterizing the properties of the materials prepared in Examples 1-5, such as the aniline point, tarnishing, and brittleness.

 The composition of the material and its properties are shown in tables 1 and 2.

 In these tables, / 1 / denotes the aromatic oil product "Repex E-7" of the company Repsol Derivatives, / 2 / denotes the semi-aromatic oil product "SMR" of the company Repsol Derivatives, and / 3 / denotes the diisododecyl phthalate plasticizer "DIDP", filler calcium carbonate. The filler particles have a particle size of from 1 micron to 1.25 mm.

 On the materials of examples 2-5 and on a sample of a product already known on the market and made on the basis of asphalt and ethylene propylene diene polymer, sound insulation measurements were performed in the form of determining the sound absorption level, expressed in decibels, at various frequencies. These measurements were carried out using a cabin consisting of two small chambers with joint damping characteristics separated by a metal plate. In one of the cameras is a speaker system, and in another microphone, with which the sound pressure level is measured.

 First, the sound pressure level was measured with a steel plate thickness between chambers of 0.8 mm, and then the chambers were separated by a complex partition consisting of a steel plate, an absorber (porous felt 19 mm thick) and a sheet weight of 7 kg / m according to the invention. The difference in results expressed in decibels characterizes the measurement of sound insulation achieved using a complex partition formed by an absorbing material and a tested sound-absorbing material in accordance with this invention.

 From table 2 it follows that the level of sound absorption of the sample material is lower than that of the materials in examples 2-5. TTT1

Claims (1)

A thermoplastic material designed for sound absorption and vibration isolation, containing chlorinated polyethylene with a chlorine content of 20 - 95% softener and fine filler, characterized in that as a softener it contains a compound selected from the group: aromatic oil with the following characteristics:
Specific gravity at 15 ^o 0.98 1.00
Viscosity, ^o E at 50 ^o С 180 260
Flash point in an open crucible, ^o С 270 minimum
Pour point, ^o С +15 maximum
Aniline point, ^o C 75 maximum
Water, vol. 0.1 maximum
or semi-aromatic oil with the following characteristics:
Specific gravity at 15 ^o С 0.92 0.94
Viscosity, ^o E at 50 ^o C 65 80
Flash point in open crucible, ^o C 300 minimum
Pour point, ^o С -9 maximum
Aniline point, ^o C 102
Color 7 maximum
The number of neutralization, mg • KOH / g 0,05
Water, vol. 0.1 maximum
Saturated, wt. 46
Aromatic, wt. 43.5
Polar, wt. 10.5
Asphaltenes 0
Paraffin hydrocarbons, wt. 63
Naphthenic hydrocarbons, wt. 22
Aromatic hydrocarbons, wt. fifteen
The refractive index at 20 ^o With 1,517
Sulfur, wt. 2,8
or di-isodecyl phthalate having the following characteristics:
Specific gravity at 20 ^o С, g / cm ^З 0.966 0.970
Specific gravity at 25 ^o С, g / cm ^З 0.963 0.967
Viscosity at 20 ^o С, st 156
Pour point, ^o C -47
Refractive index n $\genfrac{}{}{0ex}{}{\text{20}}{\text{D}}$ 1,482 1,488
Flash point (open crucible Pensky morteus) ^o C> 200
Solubility in water at 20 ^o C, wt. <0.01
Volatility, weight loss after 24 hours at 180 ^o C 7.1
Acid number, mg • KOH / g 0.07 maximum
The content of esters, wt./weight 99 minimum
Free alcohol content, wt./weight 0.1 maximum
Water content, wt./weight 0.1 maximum
Aniline point, ^o C <25
in the following ratio of components of the material, wt. h Chlorinated Polyethylene 200 225
Softener 425 850
Fine filler 4000 4500

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