JPH0458040B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a
The present invention relates to a sound insulating material mainly made of polyurethane plastic foam having open cells and having noise reduction properties.

From German Published Patent Application No. 2835329, a polyol (mixture) having viscoelasticity and containing 150 or less
Offenporige polyurethane foams with OH numbers are known.

Plastic foams of this type are used for distinguishing and muffling different regions of a sound-emitting surface, for example a vehicle body. By the way, it has been confirmed that, for example, the front wall region of a vehicle has a different surface temperature than the bottom region. Based on the clear temperature relationship, adjustment of the plastic foam to the operating temperature of the wall to be sound insulated is necessary in order to obtain an optimum loss factor.

The sound deadening of unfilled polyurethane foam car bodies available on the market is negligibly low. On the other hand, sound-deadening foams for vehicle bodies have become known from said document. However, the loss factor is relatively small, in which case also the maximum value of the silencing is obtained at low temperatures, especially at temperatures that are not very important in practice (for example in automobiles).

Furthermore, with foams having open cells or predominantly open cells, useful air silencing is generally not expected.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a polyurethane plastic foam with mainly open cells that has excellent car body and air sound deadening properties, at least in terms of viscoelastic properties.

This object is solved according to the invention by a plastic foam having a structure based on castor oil and a density of at least 120 kgm ^-3 .

Preferably, the structure is based on castor oil and diols and/or triols.

Diol-, triol- and polyol mixtures used in particular in plastic foams
It has a large OH number in the range ~250.

The OH number is the mg of potassium hydroxide equivalent to acetic acid bound by 1 g of substance during acetylation.

By adjusting the different raw materials, in particular by varying the mixing proportion between component A and diisocyanate (variation of the characteristic values), variations in the desired maximum value of the silencing can be obtained for the respective operating temperature present. Furthermore, planes which do not require local sound deadening, but which must be completely sound damped, can be considered without compromising the total sound deadening by means of voids in the plastic foam. This allows plastic foam to be saved. Furthermore, the sound deadening is obtained in a simple and inexpensive manner, in which case adjustment to locally different temperatures is possible. In particular, it is possible to adjust the raw material within the plastic foam section to locally different temperatures.

The castor oil-based construction provides a fixed maximum value of sound damping for a given temperature. The addition of diols and/or triols changes the crosslinking, which on the one hand changes the structure of the plastic foam and, on the other hand, makes it possible to shift the maximum value of the silencing for the desired temperature.

To increase density (this is not obvious for plastic foams - changes in blowing agent addition can result in a decrease in density), organic and/or
Or inorganic fillers can be added to obtain the desired minimum density or favorable price.

The sound deadening of the plastic foam vehicle body according to the invention is relatively high, resulting in loss factors d of up to 0.3 in the thickness range from the surface to the supporting material customary for the foam.

Furthermore, air sound deadening is obtained with the plastic foam according to the invention, which represents only a slight improvement over non-silent support materials, such as 1 mm thick steel plates. On the contrary, measurements according to the Bary test method (DE 2212828) yielded a greater level of difference than would be expected by the law of mass action.

Preferably, a flexible surface covering as well as a bending-resistant surface covering can be provided on the plastic foam, whereby the sound deadening of the vehicle body and the sound deadening of the air can still be significantly increased. In particular, the width of the temperature band of silencing, defined by the loss factor d of the system being the same or 0.03 larger with respect to temperature, increases.

Furthermore, since the relationship between the alcohol content and the temperature at which maximum silencing is obtained is known, the plastic foam to be assigned to the intended use can be produced optimally for the purpose. On the one hand,
The displacement of the maximum value of silencing due to high temperature is the OH of the A component.
The displacement of the maximum value of the silencing takes place with increasing value of the diol and/or triol,
In particular, the variation of the polyglycol component takes place in a linear relationship. In this case, first of all, castor oil is simply used as a raw material for adjusting the maximum value of the silencing for a given temperature, in particular 20°C, and then the maximum value of the silencing can be adjusted depending on the circumstances of use by other components, namely diols and /or displacement by mixing triol components (e.g. polyglycols).

The invention will now be described with reference to the accompanying drawings.

The curves for the plastic foam according to the invention shown in the drawings are based on the following composition: Composition 1 Component A Castor oil 100 parts = 51.7% Polyglycol (polyol for crosslinking)
5 parts = 2.6% Cell opener (acryl polyol 1180)
20 parts = 10.3% dibutyltin dilaurate (DBZDL)
0.5 part = 0.3% Water 1 part = 0.5% Frigen [trade name, manufactured by Hoechst] (blowing agent)
2 parts = 1.0% OH value = 230 B component diisocyanate (MDI) 65 parts = 33.6% 193.5 parts = 100.0% Composition 2 A component castor oil 95 parts = 42.0% Polyglycol 10 parts = 4.4% Cell opener (acrylic acid) roll polyol 1180)
20 parts = 8.8% dibutyltin dilaurate (DBZDL)
0.5 part = 0.2% Water 1 part = 0.4% Frigen [Product name, manufactured by Hoechst]
4 parts = 1.8% DABCO (amine, accelerator) 0.5 parts = 0.2% Barite (inorganic filler) 20 parts = 8.8% OH value = 250 Component B diisocyanate (MDI) 75 parts = 33.4% 226.0 parts = 100.0% Composition The density of composition 1 is approximately 175 Kgm ^-3 and the density of composition 2 is approximately 180 Kgm ^-3 .

Acrol Polyol 1180
is a medium molecular weight polyoxypropylene/polyoxyethylene triol manufactured by Atlantic Richfield and used as a cell opener.

The two compositions differ, inter alia, not only by the different proportions of polyalcohol, but also by the fact that composition 1 has a milder regulator than composition 2.

Both compositions 1 and 2 are contained in a matrix composition having: (A): Castor oil 100 parts Polyalcohol (diol and/or triol) 0...20 parts Filler 0... 200 parts Blowing agent 0.5...10 parts Accelerator, foam control agent As required (B): Diisocyanate (MDI, NDI, TDI, etc.) Stoichiometric amount In this case, the deviation of the characteristic values is normal.

For formulations 1 and 2 present in this case, the mixing ratio is approximately 2:1 (by weight). In this case, not only can the individual component B vary in proportion to the mixture component A, but also the composition of the mixture component A can change with respect to variations in the mixture proportion.

1 to 5, the loss coefficient at a frequency of 200 Hz is shown with a constant thickness x as a parameter. Thickness x=20 represents that a plastic foam of approximately 20 mm thickness was measured on a steel plate as support material. A slight variation in the thickness of the plastic foam layer (19 mm or 20 mm) did not show any significant difference in practice. Furthermore, the curve 1,1 of X=10.0 in FIG. 1 for composition 1
A comparison of curves 1 and 2 with X=20.0 shows that small variations in layer thickness are not significant. Furthermore, the first
Curves 1 and 2 in the figure represent layer thickness x for composition 1
=20.0 indicates that the loss coefficient d reaches its maximum value within the range of 20°C or less.

Curves 2, 2 and 2, 1 in FIG. 2, which were measured under otherwise the same conditions for composition 2,
shows that the loss coefficient d of layer thickness x=20.0 according to curve 2, 2 has its maximum value at about 40°C. This maximum displacement of sound deadening towards higher temperatures is obtained by the large polyglycol component of composition 2.

Through testing, the displacement of the maximum value of silencing was determined by the displacement of the A component.
It was shown that the relationship was mainly linear with the change in OH value.

On the other hand, curves 3, 1, 3, 2 according to Fig.
and 3,3 were measured on a known plastic foam according to DE 2835329 A1. Various layer thicknesses 10, 0, 20, 0 and 3
The 0,0 curve indicates that the loss factor has a maximum value of silencing that exists below at least 0°C. This is not very important for practical use.

Furthermore, it has been found that in order to obtain the same loss factor at high temperatures, significant layer thicknesses are required, which is a disadvantage in practice.

The plastic foam according to the invention has a locally varying composition with respect to its loss coefficient, so that the loss coefficient varies such that its maximum value is obtained within a certain temperature range predetermined in each case of use. be able to. Furthermore, the plastic foams may have the same composition. in fact,
First, a composition of component A is formed, which is (simply) based on castor oil, in which the castor oil component primarily determines the loss factor, with a maximum value within a range of about 20°C. By appropriate variation of the OH number, ie by adding diols and/or triols, in particular polyglycols, the maximum value of the loss factor is then shifted within the respective desired temperature range. This can be done - as mentioned above - by objectives.

By providing a surface coating, the loss factor in the plastic foam according to the invention can be increased significantly, as shown for compositions 1 and 2 individually in FIGS. 4 and 5. . In order to be able to carry out clear measurements, plastic foams with very small layer thicknesses were used. Figure 4 shows a steel plate of 1 mm as support material and a plastic foam of composition 1 of about 7 mm.
mm and surface coating made of polypropylene approximately 2 mm
For the case of a layer thickness ratio of 1:7:2 corresponding to A clear maximum value of the loss factor is found at 20° C., in which case the value of the maximum value is larger than in the case of FIG. 1, despite the small overall thickness.

Curve 5,1 in FIG. 5 shows that for the corresponding thickness ratio 1:6:2, the loss factor for composition 2 is 40°C.
2, the total thickness is likewise smaller than in the case of a plastic foam without surface coating, as described for the curve in FIG.

Figures 6 and 7 are German Industrial Standards (DIN)
52210 shows the frequency silencing relationship. curve 6,
1 or 7,1 indicates the relationship for a non-silencing support material, in this case a 1 mm thick steel plate with a flat mass of 7.8 Kgm ^-2 .

Curve 6.2 is coated with a 15 mm thick layer of plastic foam according to the invention and has a planar mass of 11.3
The relationship is shown for a steel plate with Kgm ^-2 . Curve 7.2 shows the same relationship for a layer of plastic foam 30 mm thick and a total mass of 14.2 Kgm ^-2 .

Curve 6,3 is the thickness with the arrangement described in curve 6,2.
A 2.5 mm flexible surface coating is provided on the plastic foam layer, with an overall mass of 18.3 Kgm ^-2
The relationship is shown in the case of . Curves 7 and 3 are 2.5mm thick
A comparative relationship is shown in which a flexible surface covering of 20 mm is provided on a layer of plastic foam 30 mm thick, resulting in an overall mass of 21.3 Kgm ^-2 .

FIG. 8 shows the measurement of the level difference of a 30 mm thick plastic foam according to the invention at various mixing proportions, determined by the method of DE 22 12 828. Curve 8,3 in this case shows the theoretical difference obtained on the basis of the mass of the plane, which is a straight line. This theoretical difference is significantly larger than the actually measured difference, which varies depending on the respective mixing ratios and frequencies. Curve 8, 1 is the mixing ratio
2.25:1, and curve 8,2 has a mixing ratio of 200:1.
It was measured with

In the curves according to FIGS. 6, 7 and 8, it can be seen that the actual composition is not important for the qualitative course of the curves. Simply quantitatively other silencing values can be ascertained by varying the mixing proportion.

Curves 6, 2, 7, 2 and 8, 2 therefore relate to plastic foams according to the invention without a covering layer. Curves 6,3 and 7,3 are curves 6,2
or 7,2 exhibiting a mass-elastic-silencing behavior, ie a somewhat clear resonant frequency and an associated relatively rapid increase.

The curves in FIG. 8 show the level of difference due to different softness or hardness of the plastic foam according to the invention.

As a result, it turns out that the plastic foam according to the invention has significant advantages over conventional plastic foams. In addition, the plastic foam can be made of economically advantageous raw materials, such as barite, for example, in order to increase the mass and reduce costs. Furthermore, as mentioned above, the maximum value of the local sound damping can be determined optimally from the beginning, ie on the already finished side, depending on the respective factors, for example especially the temperature. This is advantageous in particular when the plastic foam according to the invention is constructed as a self-supporting molded part or floorboard part, for example when sound deadening the bodywork of a motor vehicle.

In addition, raw materials and the resulting costs can be saved by providing voids in the plastic foam in areas where the corresponding areas of the supporting material do not require local sound damping, regardless of whether the entire supporting material is to be sound dampened. .

Furthermore, the use of particularly bend-resistant surface coatings allows the space requirements to be reduced compared to conventional sound-absorbing coatings.

EXAMPLE FIG. 9 shows cut sections of plastic foams 9,2 of different thickness made according to the invention glued onto a thin-walled support material 9,1. Furthermore, the plastic foam 9,2 is provided with a flexible surface covering 9,3.

Furthermore, FIG. 9 shows that the plastic foam 9,2 is provided with locally different mixing proportions 9,4 in order to adapt to locally different temperatures (in particular of the support material 9,1).
or 9,5. In the illustrated embodiment, the thin-walled support material 9,1 is a patterned body plate of a motor vehicle.

Furthermore, cavities 9,6 are provided in the plastic foam 9,2 in areas of the support material 9,1 where local sound damping is not required. On the other hand, as shown on the left side of FIG.
has locally different thickness.

[Brief explanation of drawings]

Fig. 1 is a loss coefficient/temperature diagram of the first composition, Fig. 2 is a loss coefficient/temperature diagram of the second composition, and Fig. 3 is a loss coefficient/temperature diagram of the known composition. FIG. 4 is a loss coefficient/temperature diagram of the first composition having a surface coating, and FIG. 5 is a loss coefficient/temperature diagram of the second composition having a surface coating. FIG. 6 is a sound deadening/frequency diagram of the composition of the first raw material density according to the present invention, and FIG. 7 is a sound deadening/frequency diagram of the composition of the second raw material density according to the present invention. , and Figure 8 shows Barry
FIG. 9 is a level difference/frequency diagram according to the test method, and FIG. 9 is a sketch of the plastic foam on the support material. 9,1...Supporting material, 9,2...Plastic foam, 9,3...Surface coating portion, 9,4 and 9,5...Mixing ratio, 9,6...Vacancy.

Claims (1)

[Scope of Claims] 1. A sound insulation material consisting of an open-cell polyurethane plastic foam, which can be pasted onto a thin-walled support material, having a structure and density based on castor oil and diols and/or triols.
120Kgm ^-3 , castor oil and diol and/or
Or a sound insulating material made of an open-cell polyurethane plastic foam that can be attached to a supporting material and has an OH value of 150 to 250 of an alcohol made of triol. 2. The sound insulation material according to claim 1, which additionally contains diethylene glycol, dipropylene glycol, glycerin, butanediol 1-4, polyethylene glycol 200, 400, or 600 as the diol and/or triol. 3. The sound insulation material according to claim 1 or 2, which further contains a filler for increasing density. 4. Any one of claims 1 to 3, wherein the flexible surface coatings 9, 3 for increasing vehicle body silencing and air silencing can be pasted onto the plastic foams 9, 2. Sound insulation material as described in section. 5. Sound insulation material according to claim 4, wherein the plastic foam 9, 2 can have cavities 9, 6 in areas where the support material 9, 1 belongs and do not require local sound deadening. 6. The sound insulation material according to claim 4, which may be constructed as a self-supporting molded member or a floorboard member.