SU879641A1 - Oscillation absorbing laminated material - Google Patents

Description

one

The invention relates to the field of acoustic devices intended to evicts from sound waves and vibrations.

Known layered sound and vibro; absorbing materials consisting of outer metal sheets. and enclosed in between in the elastic elastic layer 1.

Although this material gives an adequate damping stability, it is, however, only at low static loads in a certain (narrow) temperature range.

Also known is a vibration-absorbing laminate consisting of two outer metal sheets and an intermediate polymer layer from a graft copolymer, which is a grafting product of 40-80 wt.% Methyl methacrylate or its mixture with methacrylic acid (the content of the latter in a mixture of 0.1-10 wt. %) by 20-60 wt.% of a four-component copolymer of vinyl acetate (3040 wt.%), n-butyl acrylate (30 40 wt.%), dibutyl maleinate (10 30 wt.%) and crotonic acid (515 wt.%) 2. ,

This material has a wide temperature range of effective damping, but its disadvantage is the ability of the polymer layer due to increased fluidity to be squeezed out from the gap between the metal plates under the influence of static compressive loads, as a result

10, a decrease in the tovocine of the intermediate polymer layer occurs, and / as a result, the vibration properties of the material significantly deteriorate.

In addition, the method of obtaining this

15, by depositing a layer of a semi-liquid prepolymer on metal sheets, i.e. a solution of a four-component copolymer in a partially polymerized monomer, is undesirable from a technical point of view. safety, because it is coupled with the inevitable evaporation of physiologically harmful methyl methacrylate.

A scheme for the preparation of a graft copolymer proposed for a known material includes the step of dissolving a copolymer of vinyl acetate with n-butyl-. krylate, dibutyl maleate and crotonic acid in the monomer, i.e. methylme30 tacrylate, which is technologically difficult.

Claims (1)

Claim Vibration-absorbing material is made by laying and pressing a three-layer package of two outer metal sheets and an intermediate layer obtained from a grafted polymer. As external metal layers, for example, aluminum alloy sheets of the AMg type 1.5 mm thick can be used. The material for the vibration-absorbing polymer layer is obtained by sequential emulsion polymerization. As an initiator, a redox system can be used, for example, an emulsifier - sodium alkyl · sulfonate. Initially, primary latex is obtained with a single loading of butyl acrylate, nitrile of acrylic acid, methacrylic. kidlots, glycdyl methacrylate. Then, vinyl35 acetate with glycidyl methacrylate is grafted onto it and the grafted copolymer is planted from the latex by freezing or adding a solution of aluminum sulfate, and then dried in the form of crumbs. After that, the resulting mass is homogenized on rollers at a temperature of 100-120 ° C and a film of 0.8 mm thickness is obtained by pressing in a framework on a hydraulic vibration-absorbing layered material consisting of two outer metal sheets and an intermediate layer of grafted copolymer, characterized in that, in order to ensure stability while maintaining high parameters of effective damping due to the absence of fluidity of the intermediate layer under the influence of static compressive loads, the intermediate polymer layer is made of the grafting product of a mixture of vinyl acetate with glycidyl methacrylate, taken in a weight ratio of 99.5: 0.5-95: 5, on a four-component copolymer of n-butyl acrylate, nitrile of acrylic acid, methacrylic acid and glycidyl methacrylate with a mass ratio of vinyl acetate with glycidyl methacrylate and a four-component copolymer 35: 65-80 and the composition of the four-component copolymer, wt.%: N-butyl acrylate Acrylic Acid Nitrile Methacrylic acid glycidyl methacrylate