JPH01263148A - Composition for composite type vibration-damping material - 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 material composition, and more specifically, it relates to a composite vibration damping material composition that constitutes a component or a part of a vehicle, electrical component, machine or structure. The present invention relates to a composition for use in manufacturing a composite damping material with high vibration absorption performance that can reduce these vibrations and reduce noise.

[Conventional technology]

In recent years, with the development of transportation systems and the proximity of residences to factories, noise and vibration problems have become a social problem as pollution, and noise and vibration regulations have also been introduced in workplaces to improve the working environment. There is a tendency to In response to these trends, there is a need to provide vibration damping performance to rigid substrates such as metal materials that are sources of noise and vibration, and to improve their vibration allocation performance.

Therefore, as one of the materials that exhibits such damping performance, a composite damping material has been proposed that has a three-layer structure in which a viscoelastic intermediate layer made of viscoelastic resin is sandwiched between two rigid substrates. For example, when the rigid substrate is metal, it can be used in automobile oil pans, engine covers, dash board panels and floors, hopper chutes, conveyor equipment stoppers, home appliances, and vibration reduction members for other metal processing machines. It has been studied and adopted in the structural members of precision machinery where vibration prevention is desired.

In this case, the metal materials constituting the two metal layers are:
For example, two metal plates may be used as long as they face each other and can sandwich a viscoelastic resin between them to form a damping material.
Examples include two concentric metal tubes, two steel sections, two molded bodies that can be stacked on top of each other, a metal molded body and a backing plate, and other two-layered structures. and,
The metal forming the metal layer mentioned here is not particularly limited, but usually includes iron, aluminum, copper, lead, or alloys containing these as one component, as well as zinc,
It may also be a metal material plated with tin, chromium, etc., or surface-treated with epoxy resin, melamine resin, etc.

As the viscoelastic resin constituting the viscoelastic intermediate layer of this common composite vibration damping material, a polyester resin or a resin composition consisting of a polyester resin and a polyolefin resin (Japanese Unexamined Patent Publication No. 61-89,842) is used. ), resin compositions consisting of non-quality polyester resins and low-quality polyester resins (Japanese Patent Application No. 160, 1982), acrylonitrile-butadiene copolymer JP-A-60-245,55
0), compositions comprising liquid diene polymers containing hydroxyl groups (JP-A-60-190-350, JP-A-61
-207,746 Publication, JP-A-61-261, 04
Compositions based on various resin systems have been proposed, such as Japanese Patent Application Laid-Open No. 62-167.042).

In addition, a composition prepared by mixing polyester resin with an organic peroxide as a crosslinking agent and a filler (Japanese Patent Publication No. 53-9.794
The present inventors have also added various additives such as a resin composition consisting of an amorphous polyester, an acid anhydride, and an epoxy compound (Japanese Patent Application No. 160, No. 219/1982). Compositions have also been proposed.

By the way, the first characteristic required of such a composite damping material is high damping performance, which is generally expressed by the magnitude of the loss coefficient. and,
Second, composite damping materials are also used as structural members.
Furthermore, since it is subjected to secondary processing such as press processing, the adhesive strength, especially the shear adhesive strength, between the viscoelastic intermediate layer made of a viscoelastic resin and the outer metal layer is high. moreover,
Third, the composite vibration damping material that has undergone press processing is heated to 200℃.
It is also required that the intermediate layer resin composition does not flow out at around this temperature, since the intermediate layer resin composition may be subjected to a baking coating process in which it is heated to a certain temperature.

In particular, in the case of an allocation material that exhibits excellent allocation performance in the room temperature range of 0 to 60°C, the glass transition region of the viscoelastic intermediate layer resin composition must be near or below room temperature, and the elastic modulus at room temperature must be It has a low composition. On the other hand, compositions exhibiting a high modulus of elasticity are generally superior in terms of shear adhesion ')lUt without significantly affecting press workability. In other words, the vibration damping performance required for a composite vibration damping material and the shear adhesive strength related to press workability are contradictory requirements regarding the elastic modulus of the viscoelastic intermediate layer resin, and the above-mentioned conventional viscoelastic composition Composite vibration damping materials manufactured from synthetic materials cannot fully satisfy both of these characteristics, and are insufficient as viscoelastic compositions for vibration damping materials. Although the vibration damping performance of a mixture of a synthetic thermoplastic resin and a non-grade thermoplastic resin may be satisfactory, the adhesive strength and mechanical strength are inferior due to the incompatibility of the different polymers, which is not satisfactory. Ta.

Furthermore, non-grade polyester resins are known to have excellent adhesion to metal materials, but in particular they have a low glass transition temperature that exhibits vibration damping performance at room temperature. In the case of resin, the shear adhesive strength does not show a value high enough to withstand press processing, and it cannot be said to be a satisfactory material.

[Problem to be solved by the invention]

The present invention was devised in view of these points of view, and provides excellent vibration damping performance particularly in the low to room temperature range, has good adhesion to metal materials, and has a viscous viscosity that does not easily flow out even near the paint baking temperature. It is an object of the present invention to provide a composition suitable for producing a composite damping material capable of forming an elastic intermediate layer.

[Means for Solving the Problems] That is, the present invention uses a functional group-containing diene-based thermoplastic polyester resin having a glass transition temperature of -30 to 60°C and a loss tangent of 0.5 or more at this glass transition temperature. This is a composite vibration damping material composition that contains a polymer and a crosslinking agent.

The present invention will be explained in detail below. First, the composite vibration damping material according to the present invention has a so-called 3N structure in which a viscoelastic intermediate layer for bonding these metal layers to each other is sandwiched between two metal layers as described at the beginning.

The thermoplastic polyester resin constituting this viscoelastic resin composition exhibits resonance performance at room temperature, and has a rating of -30 to
It is a viscoelastic resin composition having a glass transition temperature of 60°C. If the glass transition temperature is lower than -30°C, the damping performance will be exhibited in a temperature range lower than room temperature, and the glass transition temperature will be lower than -30 to 60°C, which is usually required for compositions for composite vibration damping materials. In order to shift the glass transition temperature, it is necessary to add large amounts of high-melting point solid resins, fillers, etc., and if the temperature rises above 60°C, vibration damping performance will be exhibited in the temperature range of 80°C or higher, making glass In order to shift the transition temperature to a lower temperature side, it is necessary to add a large amount of plasticizer. If a large amount of these various additives is used, it is not preferable because the adhesiveness may deteriorate or it may become easy to flow at high temperatures.Also, the loss tangent (tan δ) at the glass transition temperature is not desirable from the viewpoint of allocation performance. 0.5
Preferably, the angle should be 0°7 or more. If this loss tangent (tan δ) is smaller than 0.5, satisfactory allocation performance cannot be achieved.

Such polyester resins include highly crystalline saturated polyesters such as polyethylene terephthalate and polybutylene terephthalate, which are dissolved in ethylene glycol at high temperatures to produce triethylene glycol, 1,4-butanediol,
It can be synthesized by adding a saturated polyhydric alcohol such as neopentyl glycol and performing a transesterification reaction, or it can also be synthesized by copolymerizing a saturated polycarboxylic acid and a saturated polyhydric alcohol. Saturated polycarboxylic acids used in the latter synthesis method include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, and dodecanedione. Examples of saturated polyhydric alcohols include ethylene glycol, 1,4-
Butanediol, 1.5-bentanediol, 1.6-
Examples include hexanediol, diethylene glycol, triethylene glycol, polyethylene glycol, neopentyl glycol, propylene glycol, 1,4-cyclohexane dimetatool, pentaerythritol, and trimethylolpropane. There are many combinations of these monomers, and they are appropriately selected and used depending on the desired melting point, glass transition temperature, quality, degree of crystallinity, etc.

Moreover, the polyester resin used does not need to be one type, and a composition containing two or more types of polyester resins may be used. In addition, when two or more types are mixed, when they exhibit mutually compatible behavior, the loss tangent of the mixture exhibits a single behavior, and this loss tangent is 0.5 at the glass transition temperature.
Any above is fine. In addition, when two or more types of polyester resins exhibit incompatible behavior, there are two or more local maximum values of the loss tangent of the mixture, but the largest local maximum value among them is 0.
．． It is sufficient to show 5 or more.

Such polyester resin has a glass transition temperature (T
g) allows damping performance to be exhibited in various temperature ranges, but in order to improve low-temperature damping performance, Tg
If a resin with a low Tg is used, the adhesive strength (especially shear adhesive strength) at room temperature will decrease, making it unusable for practical use.On the other hand, if a polyester resin with a high Tg is used, although a large adhesive strength can be obtained, the low-temperature vibration damping performance will be impaired. It will be done.

Therefore, the present invention makes it possible to achieve both adhesive strength (particularly shear adhesive strength) and low-temperature vibration damping properties, which are difficult to achieve with polyester resin alone. It is characterized by containing a diene polymer and a crosslinking agent.

Such functional group-containing diene polymers are diene polymers that have functional groups such as hydroxyl groups, amino groups, carboxyl groups, epoxy groups, and isocyanate groups at the end of the molecule or within the molecule. Butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-
Acrylonitrile copolymer 1, butadiene-2-ethylhexyl acrylate copolymer and butadiene-
Examples include n-octadecyl acrylate copolymers.

There is no particular limitation regarding the molecular weight, and low molecular weight
It can be used in a wide variety of ways, from liquid to high-molecular-weight solids.

The preferred blending amount of these diene polymers is 5 to 50 parts by weight, more preferably 10 to 40 parts by weight, based on 100 parts by weight of the polyester resin. If it is less than 5 parts by weight, the effect of improving low-temperature vibration damping performance will be small, and if it exceeds 50 parts by weight, the shear adhesive strength will be greatly reduced.

However, although a composition containing only a polyester resin and a diene polymer improves low-temperature vibration damping performance, it does not have enough shear adhesive strength for practical use and requires the addition of a crosslinking agent.

Such a crosslinking agent may be a compound having two or more functional groups that can react with both the hydroxyl group or carboxyl group at the end of the polyester resin and the functional group of the functional group-containing diene polymer, such as isocyanate compounds, epoxy Examples include compounds, acid anhydrides, amine compounds, aziridyl compounds, and oxazoline compounds. Among these crosslinking agents, particularly preferred are isocyanate compounds, epoxy compounds, and acid anhydrides that are highly reactive with the hydroxyl group at the end of the polyester resin.

Further, these crosslinking agents may be used alone or in combination of two or more. Furthermore, various catalysts can be used to promote or delay the reaction between functional groups as required.

The amount of these crosslinking agents added varies depending on the type of crosslinking agent, but is usually 0.1 to 50 parts by weight, preferably 0.2 to 20 parts by weight, preferably 0.1 parts by weight, per 100 parts by weight of polyester 48I resin. If the amount is less than 50 parts, sufficient improvement in shear adhesive strength will not be obtained, and if the amount added is more than 50 parts, vibration damping performance will deteriorate.

Further, in order to further improve the shear adhesive strength of the composition of the present invention, an inorganic filler may be added. Such inorganic fillers must be ones that do not thermally decompose even when heated to about 200°C, and examples include carbon bran, silica, alumina, clay, titanium oxide, zinc white, mica, and graphite. It is desirable to use one or more of carbon black, silica, or clay, especially since it has a large effect of improving shear adhesive strength at high temperatures.
The amount added is preferably 1 to 100 parts by weight, particularly 5 to 50 parts by weight, per 100 parts by weight of the polyester resin.

In addition, resins other than polyester and diene polymers may be mixed into the composition of the present invention in order to improve the vibration damping performance or increase the elastic modulus within a range that does not impair its overall performance as a vibration damping material. You can. Examples of these resins include polystyrene, AS resin, ABS resin, M
S resin, styrenic resins such as impact-resistant polystyrene, acrylic resins such as polymethyl acrylate, polymethyl methacrylate, polyethyl methacrylate, acrylic copolymers, polyvinyl chloride, vinyl chloride/vinyl acetate copolymers, chloride Vinyl chloride resins such as vinyl/acrylic acid ester copolymers, ethylene/α-olefin copolymers, ethylene/vinyl acetate copolymers, ethylene/acrylic acid copolymers, ethylene/methacrylic acid ester copolymers, ethylene/ Ethylene resins such as metal crosslinked methacrylic acid copolymers, propylene resins such as propylene/ethylene copolymers, propylene/butene copolymers, and thermoplastic resins such as non-grade polyamides such as copolymerized nylon. I can give an example.

Furthermore, a plasticizer may be added in order to shift the glass transition temperature of the resin composition to a desired value. Plasticizers used for this purpose include, for example, polyester plasticizers, polyether ester plasticizers, phosphoric acid esters, epoxy plasticizers, ester plasticizers such as phthalic acid diesters, sebacic acid diesters, etc. Examples include acid plasticizers and chlorinated paraffins, which are appropriately selected and used depending on the polyester resin used.

On the other hand, for resin compositions with low glass transition temperatures,
It is also possible to shift the peak characteristic temperature to a higher temperature side by adding a substance such as a solid resin having a melting point higher than the glass transition temperature. Examples of solid resins such as D include alkylpheno-2° resins, terpene phenol resins, rosins, rosin esters, hydrogenated rosin esters, coumaron-indene resins, phenol-modified coumaron resins, petroleum resins, etc. , and are appropriately selected and used in consideration of compatibility with the resin composition to be used.

Furthermore, conductivity can be imparted to the viscoelastic composition by blending it with a conductive solid substance as a filler, and the resulting damping material can be made into a material that can be spot welded. Examples of tetraelectric substances used for this purpose include metals such as stainless steel, zinc, tin, copper, brass, and nickel processed into powder, flake, fiber, wire, etc. can. These conductive substances can be used alone or in combination of two or more. If this conductive substance is in powder form, its maximum particle size, if it is in flake form, its maximum thickness, and if it is in fiber form, its maximum diameter is determined by its representative length. (L), in order to obtain better spot weldability, the ratio (L/T) between this representative length (L) and the thickness (T) of the intermediate resin layer of the composite damping material is 0.
．． 5 or more, preferably 0.8 or more, more preferably 1.
It is better to set it to 0 or more.

The II thickness of the composition layer of the present invention is appropriately selected based on the required vibration damping performance, etc., but from the viewpoint of vibration damping performance, the II
It is preferable that the friction is 20 μm or more, especially 20 μm or more, and 300 μm or less, especially 20 μm or less from the viewpoint of press workability of the composite vibration damping material.
0μ steel or less is preferable.

There are no particular restrictions on the method for producing the composite damping material using the composition of the present invention, and any method may be used, such as a batch method using a cut plate or a continuous method using a coil. I can do it. On the other hand, methods for compounding viscoelastic resin and metal materials include methods such as applying a paint-like product in which viscoelastic resin is dissolved in a solvent to metal materials and bonding them together, and using a T-die extruder or the like to bond metal materials together. Examples include a method in which an intermediate layer of viscoelastic resin is formed on top of the resin composition, and a method in which a viscoelastic resin in the form of a film produced off-line is sandwiched between metal materials as an intermediate layer and hot-melt bonded. Any method can be adopted depending on the purpose, such as the type of composite damping material to be used.

〔Example〕

The present invention will be described below based on Examples and Comparative Examples.

As the polyester resin, a thermoplastic polyester with a glass transition temperature of 15°C and a tan δ of 1.2 was used, and as the functional group-containing diene polymer, hydroxyl- or carboxyl-terminated liquid polybutadiene (manufactured by Nippon Soda) was used. ), carboxyl- or amino-terminated butadiene-acrylonitrile copolymer (manufactured by Ube Industries, Ltd.) and carboxyl-terminated styrene-butadiene copolymer (
Asahi Kasei ■) was used. Further, as a crosslinking agent, pyromellitic anhydride and a tetrafunctional epoxy compound were used in combination.

The film compositions to be tested in these Examples and Comparative Examples were prepared by the method described below.

First, polyester resin is put into a roll, and the first
The diene polymer, carbon blank, and crosslinking agent shown in the table were added and kneaded at 100'C to 180C to obtain a composition. This kneaded product was heated at a temperature of 120'C to 170'C, sandwiched between Teflon sheets, and pressed to produce a film with a thickness of about 70 μm.

The above film was sandwiched between two 0.8 mm thick cold-rolled steel plates and heated and pressed at 200° C. for 1 minute to obtain a composite vibration damping material having a viscoelastic resin intermediate layer with a thickness of 7011 seconds after bending. T-peel adhesive strength is <5 based on JIS-6854 test method.
Evaluated at a tensile rate of 0mm/+lin, the shear adhesive strength was 5+nm/m based on the J Is-6850 test method.
Evaluation was made at a tensile speed of in. In addition, damping performance is evaluated by measuring the loss coefficient (η) representing vibration absorption ability using the mechanical impedance method, and measuring the maximum value of η (η□, ) and the temperature (T9) when this η□8 is shown. The low-temperature damping performance was evaluated by the loss coefficient (η2°C) at 20°C.

Furthermore, the glass transition temperature (Tg) and loss tangent (tan δ) of the viscoelastic substance were measured using a non-resonant dynamic viscoelasticity measuring device using two samples of 3m11 x 3III1 x thickness l+m, and measuring the frequency in shear mode. 10112, heating rate 2℃
α1 was determined by a temperature dispersion test at 7 mrn.

Table 1 shows the results of tests conducted by sandwiching these films between steel plates.

The examples show the results of adding carbon black, a functional group-containing diene polymer, and a crosslinking agent to the polyester resin, and the comparative examples show the results when at least one of the functional group-containing diene polymer and the crosslinking agent was not added. The results were shown.

In Examples 1 to 7, in which various diene polymers and crosslinking agents were added to polyester resin, the adhesive strength at room temperature was almost the same as that in Comparative Example 2, in which crosslinking agent was added to polyester resin, but at low temperatures The damping performance of was significantly improved.

Furthermore, in Comparative Examples 1 and 3, in which only the polyester resin Kadoku and a diene polymer were blended therein, the adhesive strength at room temperature was significantly reduced.

From the above, it was confirmed that a composition prepared by blending various diene polymers having functional groups with a polyester resin and further adding a crosslinking agent has excellent adhesion at room temperature and exhibits good oscillation performance.

〔Effect of the invention〕

The composition of the present invention is sandwiched between two metal materials, and the resulting composite vibration damping material has excellent adhesive properties and exhibits excellent vibration damping performance at around room temperature, making it extremely useful in industry. Useful.

Claims (1)

[Claims] A composite damping type made by blending a functional group-containing diene polymer and a crosslinking agent with a thermoplastic polyester resin having a glass transition temperature of -30 to 60°C and a loss tangent of 0.5 or more at this glass transition temperature. Composition for materials.