JPS63193831A - Composite type vibration-damping laminate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a composite vibration damping laminate made of 3iJtl, which is composed of a thermoplastic polymer material layer and metal layers sandwiching it from both sides. In particular, the present invention relates to a composite damping laminate in which a thermoplastic polymer material, Fi, is supplied in the form of a film by an extrusion method, and can be manufactured by the industrially advantageous real press method or roll lamination method.

(Prior Art) In recent years, with the development of industrial machinery and home appliances, noise and vibration generated by various mechanical devices have become a problem from the viewpoint of health and hygiene and environmental conservation. In particular, the development of transportation systems and the rise in the prevalence of automobiles have been remarkable, and the accompanying noise has been raised as a social problem, and noise prevention measures have been demanded.

One such measure is the use of a composite vibration damping laminate, which has a polymer material layer sandwiched between two metal plates, and its scope of application is automobile engine parts (oil pans and engine covers), body parts, etc. (dash panels, doors, hoods, etc.), home appliances, metal processing machines, ducts, building materials (roofs, fences, walls, floors, etc.), etc. In order to further expand or strengthen the application of this material in the future,
This needs to be supplied in large quantities at low cost and with stable performance. For this purpose, it is industrially advantageous to supply the polymer material layer in the form of a film by extrusion, and heat and press the layer to the upper and lower metal plates by real press or roll lamination.

Currently, as the core material resin for the composite splittable laminate, homopolymer types such as vinyl acetate resin and vinyl chloride resin, as well as ethylene-vinyl acetate copolymer, acrylonitrile-
Attempts have been made to use copolymer-type thermoplastic resins such as styrene copolymers, or thermosetting resins such as urethane-based, epoxy-based, and polyester-based resins.

(Problems to be Solved by the Invention) However, the composite damping steel plates using the above-mentioned resins as core resins each have the following drawbacks.

Vinyl acetate resin has good distribution properties, but this is only visible in a limited temperature range, and it also has the disadvantage that it is difficult to form into a film coil, and it lacks flexibility.
One possible solution to this problem is to create a three-layer film in which both sides of the vinyl acetate resin are wrapped with a non-blocking resin, but since it is easier to produce a film in grasslands, it is not possible to create a three-layer film. Undesirable.

Next, vinyl chloride resin essentially has no adhesion to metal plates and requires an adhesive. Ethylene-vinyl acetate copolymer can be made into a film, but acrylonitrile-styrene copolymer has poor vibration damping properties.
In addition, thermosetting resins, which do not have the same adhesive strength as vinyl chloride resins, are inherently unable to be formed into films.

Therefore, an object of the present invention is to provide a thermoplastic polymer that solves the above-mentioned problems of the core resin used in the composite vibration-damping laminate, has excellent thermal adhesion and damping properties, and has good film formability. An object of the present invention is to provide a composite vibration damping laminate whose material layer is a core resin.

(Means for Solving the Problems) Therefore, in order to achieve the above object, the present inventors have made extensive studies and found that relatively large atomic groups (e.g. We thought that the presence of an aromatic ring would improve vibration damping properties, and came up with the idea of using xylene resin as the core resin. Based on this idea, we added self-adhesive properties and thermoplasticity to xylene resin,
As a result of studies to obtain a resin composition that can be made into a polymer film, the present invention was arrived at. The resin composition used in the present invention is made by changing the type and blending ratio of other resins blended with the xylene resin. It was also found that the temperature dependence of damping properties could be controlled by this method.

Here, the gist of the present invention is to provide a composite vibration damping laminate having a three-layer structure of a thermoplastic polymer material layer and a metal layer sandwiching this from both sides, in which the thermoplastic polymer material is (A ) 5 to 25 parts by weight of xylene resin, (B) 5 to 45 parts by weight of polyethylene resin, and/or ethylene-
5 to 70 parts by weight of a vinyl acetate copolymer, and if necessary, 40 parts by weight or less of a thermoplastic elastomer (C);
D) A composite vibration damping laminate characterized in that it is a homogeneous resin mixture containing one or both of 15 parts by weight or less of a styrene-based low molecular weight copolymer.

As the thermoplastic elastomer of component (C), styrene-butadiene-styrene block copolymer (SBS block copolymer), styrene-isoprene-styrene block copolymer, etc. are preferable.

(effect) The present invention will be explained in detail below.

In the resin composition serving as the core material resin of the distributed laminate of the present invention, the xylene resin used as component (A) is m
- It is a resin obtained by heating xylene and formaldehyde in the presence of a strong acid catalyst, and has a structure in which m-xylene nuclei are connected by ether, acetal, methylene bonds, etc., and a methylol group is present at a part of the terminal part. An example of a 0-repeat structure that is a resin having the following properties is shown below.

Although xylene resin itself has a large vibration absorption ability (that is, a large vibration absorption coefficient tan δ) especially in the room temperature range, it is inherently weak and difficult to form into a film. In the present invention, it is preferable to use a xylene resin having a ring and ball softening point of 70° C. or higher in order to ensure kneadability with other components of the resin composition. The xylene resin is present in the core resin composition in a relative proportion of 5 to 25 parts by weight. If this amount exceeds 25 parts by weight, it will be difficult to form the obtained resin composition into a film, and if the amount of xylene resin is less than 5 parts by weight, the desired good splitting properties will not be obtained, especially around room temperature.

Components (B) of the core resin composition in the distributed laminate of the present invention
) is either or both of a polyethylene resin and an ethylene-vinyl acetate copolymer, and it is preferable to use both of these resins.

The polyethylene resin used as component (B) can be of high density, medium density, or low density, but in the sense of forming a film, polyethylene resin with a molecular weight of about 2 to 70 and a melt index obtained by a high pressure method is preferred. Low density polyethylene is preferred. Polyethylene resin adjusts the viscosity of xylene resin to t'8, improves its brittleness, and facilitates film formation. In order to achieve this effect, it is necessary to mix at least 5 parts by weight of polyethylene resin with 5 to 25 parts by weight of xylene resin. On the other hand, if the polyethylene resin is present in an amount exceeding 45 parts by weight, vibration damping properties may be deteriorated.

The other resin that can be used as component (B), ethylene-vinyl acetate copolymer, also has the effect of improving the brittleness of xylene resin and making it easier to form into a film, and also has the effect of increasing the temperature at which it exhibits vibration damping properties. In other words, when the ethylene-vinyl acetate copolymer is added to the core resin composition used in the present invention, the temperature at which the oscillation property is exhibited is lowered, and the temperature at which vibration is exhibited is lowered to around room temperature. Maximum vibration damping performance can be obtained. To obtain these effects, it is necessary to use at least 5 parts by weight of ethylene-vinyl acetate copolymer per 5 to 25 parts by weight of xylene resin, whereas if this exceeds 70 parts by weight, the amount of xylene resin increases. The ethylene-vinyl acetate copolymer used has a vinyl acetate content of 18 to 28% by weight and a melt index of 6 to 400.
Polymers having a high molecular weight are desirable from the viewpoint of forming a film, but those having too high a molecular weight are not preferred because they have poor kneading properties with other resins.

The thermoplastic elastomer used as component (C) may be added to the core resin composition of the vibration damping laminate of the present invention in an amount of 40 parts by weight or less, if necessary, in order to impart cold resistance and heat resistance to the resin. It can be blended with This thermoplastic elastomer also
It has the added value of increasing the temperature at which it exhibits vibration damping properties. In order to fully obtain this effect, it is preferable to add a small amount (at least 2 parts by weight) of the thermoplastic elastomer; if the amount of the thermoplastic elastomer exceeds 40 parts by weight, the xylene resin-containing resin composition will As the thermoplastic elastomer, it is desirable to use one with a melt index of 2 to 3. For the purpose of the present invention, any thermoplastic elastomer can be used, but
Specific examples thereof include styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, ethylene-propylene elastomer, and ethylene-propylene-diene monomer co-t1.

The styrenic low molecular weight copolymer is a copolymer of styrene and a styrene derivative (e.g. α-methylstyrene) and/or maleic anhydride with a molecular weight of about 1000 to 1500, and has a molecular weight of about 1000 to 1500. If necessary, it is added to the core resin composition in an amount of 15 parts by weight or less for improvement. The amount of this styrenic low molecular weight copolymer is 1
When the amount exceeds 5 parts by weight, it becomes difficult to form a resin composition containing a brittle xylene resin into a film. In order to sufficiently improve wettability, it is preferable that at least 2 parts by weight of the above-mentioned low molecular weight copolymer be present.

As described above, according to the present invention, by blending xylene resin into the thermoplastic polymer material used as the core resin layer of the composite damping laminate, it is possible to obtain vibration distribution properties at around room temperature.

Furthermore, by blending component (B) polyethylene resin and/or ethylene-vinyl acetate copolymer resin in the above relative weight ratio, the viscosity of the xylene resin is adjusted, its brittleness is improved, and xylene resin-containing A composite vibration damping method that makes it easy to form a resin composition into a film and exhibits good vibration damping performance especially at room temperature using an industrially advantageous method such as hot press or roll lamination to heat and press the film. It becomes possible to produce a flexible laminate.

FIG. 1 is an explanatory diagram illustrating the three-layer structure of the composite type distributable laminate of the present invention. As shown in the figure, the laminate of the present invention has a thermoplastic polymer resin layer between the upper and lower metal layers. has,
This is a so-called restraint type composite vibration damping laminate. The upper and lower metal plates are not particularly limited, but are usually steel plates such as cold-rolled steel plates, carbon steel plates, low alloy steel plates, stainless steel plates, and high-strength steel plates.

However, metal plates other than steel plates, such as aluminum plates, can also be used. The thickness of each metal plate is 0.1 to 3.2 mm,
The thickness of the intermediate core resin layer is preferably within the range of 20 to 150 mm.

To produce the vibration damping laminate of the present invention, a predetermined proportion of each raw resin component is fed together into a screw extruder type kneader and kneaded under appropriate heating to obtain a homogeneous resin mixture.

It is easier to use this resin mixture for the next film forming process if it is pelletized.6 Next, this resin mixture is
A film is formed to a predetermined thickness by a suitable film forming method such as a T-die method or an inflation silane method. Kneading and film formation can be carried out by any known conventional means, and working conditions such as temperature can be appropriately set by those skilled in the art.

Instead of preparing a homogeneous resin mixture with 8 g of pre-mixed a as described above, each resin component was fed directly to the film extruder,
It is also possible to prepare a homogeneous resin mixture in the kneading section of the extruder. On the other hand, after cleaning the surface of the metal plate by degreasing, etc., a resin film is sandwiched between two metal plates to form a laminated structure, and the resin layer and the metal plate are heat-pressed by appropriate means such as heat press or roll pressure bonding. The damping laminate of the present invention is obtained by further cold pressing if necessary.

The present invention will be further explained by the following comparative examples and examples.

Comparison ■ Soil vinyl acetate resin (Reo Cheap, B-2 manufactured by Co., Ltd.)
A film of 5YG-17) with a thickness of 100 μm was prepared by the hot-node press method, and then the film was sandwiched between two cold-rolled steel plates of 0.8 mm thickness that had been degreased with alkali.
Hot pressing was carried out under the conditions of 70'Cxlomin and a surface pressure of 30 kg/-, and the product was further cooled in a cooling press to produce an integrated laminate. Using a test piece cut into a size of 20 x 22 pieces, the loss factor was measured at 1000 Hz by the mechanical impedance method. The temperature dependence of the loss coefficient at 1000 Hz of this damping laminate is
As can be seen from the figure 0 shown as curve ■ in the figure, the loss coefficient is very high near 80℃, but the range of good loss coefficient (η>0.1) is 30℃ between 70 and 100℃. It is narrow with only a width of .

Comparison ■1 Ethylene-vinyl acetate resin (manufactured by Sumitomo Chemical Co., Ltd. 2010)
F, vinyl acetate content: 25% by weight) was made into a film with a thickness of 50μ by the T-die method.Then, a laminate was made in the same manner as in Comparative Example 1, and the one-member lapse coefficient was measured in the same manner.

The temperature dependence of the loss coefficient of this laminate at 1000 Hz is also shown in Figure 2 as a curve ■. 7 with a range of (η > 0.1) from 20 to 90°C
0℃ and wide.

After putting the blended pellets with the composition shown in Table 1 into the supply hopper of an extruder equipped with a T-die and heating and kneading them in the kneading section,
It was extruded through a T-die at a resin temperature of 150-200°C to form a 50-thick film. As the resin material, a xylene resin having a ring and ball softening point of 70 to 140°C was used. The polyethylene resin is high-pressure polyethylene (melt index 2 to 7), the ethylene-vinyl acetate resin is the resin used in Comparative Example 2, the SBS block copolymer as a thermoplastic elastomer has a melt index of 2.6, and the styrene-based low The molecular weight copolymer can be heat-pressed to the upper and lower metal plates using Esso's Niscoref A Atopress method or roll lamination method, so it can be produced in large quantities at low cost with stable performance.
A composite damping laminate having a layered structure can be manufactured. Further, by blending xylene resin into the thermoplastic polymer material used as the core resin layer of the composite vibration damping laminate, excellent vibration damping properties can be obtained at around room temperature. Furthermore, the component (B
) By blending the polyethylene resin and/or ethylene-vinyl acetate copolymer resin in the above ratio, the viscosity of the xylene resin is adjusted and its brittleness is improved,
It has become easy to form a xylene resin-containing resin composition into a film, and it has become possible to produce a composite vibration-damping laminate that exhibits good vibration-damping performance, especially near room temperature, using the above-mentioned industrially advantageous method. Become. Furthermore, it is possible to adjust the damping performance by changing the types and amounts of component (B) and components (C) and (D) that can be optionally blended. It can be controlled to achieve maximum allocation performance at the operating temperature.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the 3M structure of the composite vibration damping laminate of the present invention; and FIG. 2 is an explanatory diagram showing the 3M structure of the composite vibration damping laminate of the present invention; and FIG.
．． 2 is a graph showing the temperature dependence of the loss coefficient η of No. 2.

Claims (2)

[Claims] (1) In a composite vibration damping laminate having a three-layer structure of a thermoplastic polymer material layer and a metal layer sandwiching this from both sides, the thermoplastic polymer material is (A) xylene resin 5 to 2
and (B) 5 to 45 parts by weight of polyethylene resin and/or 5 to 70 parts by weight of ethylene-vinyl acetate copolymer.
A composite vibration damping laminate, characterized in that it is a homogeneous resin mixture containing parts by weight. (2) In addition to the resin components (A) and (B), the thermoplastic polymer substance further includes (C) 40 parts by weight or less of a thermoplastic elastomer, and (D) 15 parts by weight of a styrene-based low molecular weight copolymer. The composite damping laminate according to claim 1, which is a homogeneous resin mixture containing one or both of the following: