JPH0343244A - Damping metal composite body - Google Patents

Abstract

PURPOSE:To obtain a damping metal composite body having excellent damping capacity by laminating a composition composed of a copolymer consisting of two or more blocks composed of an aromatic vinyl monomer having a specific number average MW and a specific block. CONSTITUTION:A damping composite body is constituted by laminating a composition composed of a block copolymer with an MW of 30000-300000 consisting of two or more blocks composed of an aromatic vinyl monomer with a number average MW of 2500-4000 and one or more block composed of isoplene or isoprene-butadiene having a number average MW of 10000-200000 and containing 40% or more of a vinyl bond and having the peak of the main dispersion of tandelta at 0 deg.C or more or a hydrogenated product thereof to a metal plate. When the MW of the block copolymer is less than 30000, the mechanical properties such as strength or elongation at break of the block copolymer itself are lowered and, when said MW exceeds 300000, processability becomes inferior. When the MW of the aromatic vinyl block is less than 2500, mechanical properties are lowered and, when the MW exceeds 40000, melting viscosity becomes too high and thermoplasticity is failed.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a metal composite using a composition made from a block copolymer.

[Conventional technology] In recent years, due to the development of transportation stages, noise and vibration problems have become a major social issue. In addition, the negative effects of vibration are also a problem in the fields of precision machinery and electronics. As a result, vibration control. Demand for soundproofing performance has become stronger. BACKGROUND ART Vulcanized rubber such as NR, ITR, and SBR is used as a cover by pasting it on a metal plate in machines and equipment that are sources of vibration or noise. In addition, in recent years, vibration-damping composites made of viscoelastic materials such as polyester resin, polyamide resin, and epoxy resin bound with metal plates have been used in automobile oil pans, engine covers, floors, OA equipment, household electrical appliances, etc. ing. However, since Calosulfate rubber is compounded and pasted after being vulcanized, it is very time-consuming, and the above-mentioned viscoelastic resins have poor flexibility and have problems in processability after being made into a composite material. Further, these resins are used by being heated and pressed onto a metal plate after film formation, but the t+j resin hardens due to the heat applied during film formation, which poses a problem in the manufacture of composites. [Problem to be solved by the invention]

The present invention is a vibration-damping composite using a new thermoplastic elastomer that has excellent vibration distribution performance, can be hot melt processed, and has excellent elasticity and can be used for bending and drawing of metal plates. The purpose is to provide

[Means to solve the problem]

According to the present invention, the above problem is solved when the number average molecular weight is 2500 to
Two or more blocks consisting of a vinyl aromatic monomer of 40,000 and a number average molecular weight of 10,000 to 200,000
The vinyl bond content is 40% or more, and the temperature is 0°C or more.
It is composed of isoprene or isoprene-ptadiene having a main dispersion peak of an δ, or is composed of one or more blocks composed of hydrogenated products thereof, and has a molecular weight of 3.
The problem can be solved by constructing a composite by laminating a composition made of a block copolymer having a molecular weight of 0,000 to 300,000 on a metal plate. The above-mentioned block copolymer used in the present invention exhibits strength and elongation equivalent to that of vulcanized rubber without crosslinking because the vinyl aromatic blocks form pseudo-crosslinking points. Because of its existence, it also has properties as an elastic body. The present invention will be explained in more detail below. The first component of the block copolymer used in the present invention includes an anionically polymerizable aromatic vinyl monomer,
For example, styrene, l-vinylnaphthalene, 2-vinylnaphthalene, α-methylstyrene, 3-methylstyrene,
4-propylstyrene, 4-cyclohexylstyrene,
Examples include 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, and the most preferred is styrene. Further, isoprene or isoprene-ptadiene is suitable as the second component of the block copolymer used in the present invention. When using a monomer other than isoprene, for example, in the case of butadiene, the temperature at which vibration damping performance is developed is at most 0 even if the vinyl bond content is increased.
℃ or lower, it cannot function at the temperature actually used, and has little practical significance. In the case of isoprene, by setting the vinyl bond content according to the present invention, the temperature range is approximately 0°C to 5°C.
It can exhibit vibration damping performance in a practical temperature range up to around 0°C, making it possible to respond to a wide range of applications, which is extremely meaningful from a practical standpoint. In the case of isoprene-ptadiene, if the proportion of isoprene is 40% or more, damping performance is exhibited at 01 or more. The form of the block made of isoprene-ptadiene may be random, block, or Chibird. The vinyl bond content of the isoprene or isopray-butadiene block portion of the block copolymer used is 40% or more (or may be 100%). If the vinyl bond content is less than 40%, sufficient vibration damping performance cannot be obtained in the normal operating temperature range, which is not preferable. In addition, t obtained by measuring the viscoelasticity of the block copolymer
It is necessary that the temperature of the peak of the main dispersion of an δ (loss tangent) is 0° C. or higher. If there is a peak only at a temperature lower than 0° C., sufficient allocation performance cannot be obtained in a normal temperature range. Note that when the vinyl bond content of the isoprene block is 100%, the tan δ absorption temperature is about 60°C, so the possible upper limit is about 60°C. The molecular weight of the block copolymer obtained is 30,000 to 30
It must be in the range 0000. Molecular weight is 30
If it is less than 000, the mechanical properties such as strength and elongation at break of the block copolymer itself will decrease. Also, 30,000
When it exceeds 0, workability deteriorates. From this point of view, the molecular weight of the block copolymer is more preferably 80,000 to 2,500.
It is better to be in the range of 00. The molecular weight of vinyl aromatic pro-tsuku is 2500-4000
If the molecular weight is less than 2,500, the mechanical properties will deteriorate, and if it exceeds 40,000, the melt viscosity will become too high and thermoplasticity will be impaired, which is not preferable. Furthermore, if the proportion of the vinyl aromatic block in the block copolymer is less than 5%, the strength properties of the block copolymer will be insufficient, while if it exceeds 50%, the viscosity will become extremely high, making it difficult to process. This is not preferable because it becomes difficult and vibration damping performance deteriorates. The monomorphic form of the block copolymer used in the present invention is denoted by A (BA) n , (ATh) n, where A is a block consisting of aromatic vinyl monomers and B is a block consisting of isoprene or isoprene-ptadiene. , where n is an integer greater than or equal to 1. In the present invention, the block copolymer can be obtained by the following various methods. A method in which an aromatic vinyl compound, isoprene or isoprene-ptadiene is polymerized sequentially using an alkyllithium compound as an initiator, or a method in which an aromatic vinyl compound, isoprene or isoprene-ptadiene is polymerized and coupled with a coupling agent, or a dilithium compound is used as an initiator. Examples include a method of sequentially polymerizing isoprene, isoprene-ptadiene, and an aromatic vinyl compound as an initiator. Examples of alkyllithium compounds include alkyl compounds in which the alkyl residue has 1 to 10 carbon atoms, and methyllithium, ethyllithium, pentyllithium, and butyllithium are particularly preferred. Examples of dilithium compounds include naphthalene dilithium, oligostildilithium, dilithiohexylbenzene, and the like. Appropriate amounts to be used are 0.01 to 0.2 parts by weight of each initiator and 0.04 to 0.8 parts by weight of the camping agent based on 100 parts by weight of all monomers used in the polymerization. The block made of isoprene or isoprene-ptadiene contains 40% or more of vinyl bonds, and
A Lewis base is used as a cocatalyst during the polymerization of isoprene or isoprene-ptadiene in order to have a peak of the an δΦ main dispersion. Examples of Lewis bases include ethers such as dimethyl ether, diethyl ether, methyl ethyl ether, and tetrahydrofuran, and glycol ethers such as ethylene glycol diethyl ether and ethylene glycol dimethyl ether. N,N,N',N'-tetramethylethylenediamine. Examples include tertiary amines such as triethylenediamine, and ether-containing amines such as N-methylmorpholine and N-ethylmorpholine. The Lewis base is used in an amount of 0.1 to 400 parts by weight per 100 parts by weight of the initiator. An inert organic solvent is used as the solvent. In particular hydrocarbons having 6 to 12 carbon atoms, such as hexane, heptane,
Octane, decane and their cyclic analogs are suitable. Aromatic solvents such as toluene, benzene, xylene, etc. are also suitable. In all polymerization methods, the polymerization is carried out at a temperature of -20 DEG C. to 80 DEG C. for a period of 1 to 50 hours. Block copolymers can be produced by adding the polymer solution to a poor solvent such as methanol, solidifying it, and then drying it by heating or under reduced pressure, or dropping the polymer solution into boiling water to azeotrope the solvent, then heating or under reduced pressure. Obtained by drying. By subjecting the obtained block copolymer to a hydrogenation reaction as required, part or all of the carbon-carbon double bonds in the block consisting of isoprene or isoprene-ptadiene are hydrogenated. In the hydrogenation reaction, a method is preferably used in which molecular hydrogen is reacted with a known hydrogenation catalyst in a state dissolved in a solvent that is inert to the reaction and the catalyst. The catalyst used is Raney nickel or
Carbonizes metals such as PL, Pd, Ru, Rh, and Ni. A heterogeneous catalyst such as one supported on a single substance such as alumina or diatom, or a Ziegler catalyst consisting of a combination of a transition metal and an alkyl aluminum compound, an alkyl lithium compound, etc., are used. The reaction is carried out at a hydrogen pressure of normal pressure to 200 kg/crA, and a reaction temperature of normal temperature to 200 kg/crA.
The reaction is carried out at 50° C. for a reaction time of 0.1 to 100 hours. The block copolymer after the reaction can be produced by coagulating the reaction solution with methanol or the like and then drying it by heating or under reduced pressure, or by pouring the reaction solution into boiling water to remove the solvent by azeotropic distillation, and then drying it by heating or under reduced pressure. can get. The hydrogenation rate is determined by the level of physical properties required, but if heat resistance and weather resistance are important, hydrogenation should be at least 50%, preferably at least 70%. The block copolymer has thermoplasticity and can be easily molded by real melt. That is, the mixture is kneaded using a kneader or the like, molded using a press or the like, or kneaded and molded using an extruder, and usually cooled to obtain a molded product. The block copolymer is filled with compounding agents used in general rubber compounding, such as plasticizers such as oil, softeners, carbon blanks, reinforcing agents such as silica, calcium carbonate, talc, mica, etc., as necessary. It is used in combination with an agent. As the oil, various paraffinic, naphthenic, and aromatic oils are used. Various other vegetable or synthetic oils can also be used as long as they have good compatibility with the block copolymer and do not significantly impair processability. Preferred oils are naphthenic oils, and in particular, oils with good heat resistance are preferred in consideration of the temperature at which the vibration-damping composite is baked at the time of coating. For example, 5unthe
n250, PH10. The amount of oil added is 5 to 60 parts by weight, particularly preferably 10 to 50 parts by weight, per 100 parts by weight of the block copolymer. If the amount is less than 10 parts by weight, the processability will not be improved sufficiently. On the contrary, 6
If the amount is more than 0 parts by weight, the oil will bleed, which is not desirable. Furthermore, by blending various oils, it is possible to change the temperature range in which the present block copolymer exhibits good vibration damping performance. The filler has the effect of increasing the strength of the composition comprising the block copolymer, and mica in particular has the effect of improving vibration damping performance and heat resistance. The appropriate amount is 20 to 150 parts by weight per 100 parts by weight of the e-block copolymer. When seeking to improve damping performance by adding mica, it is preferable to add 30 parts by weight or more. In addition, various metal powders and metal fibers such as stainless steel powder and aluminum powder, or carbon blanks are used to impart conductivity and enable spot welding. Conductive particles such as graphite are blended. Additionally, a tackifier is added for the purpose of increasing metal adhesion. Coumaron resin is used as a tackifier. Various resins such as phenolic resins, terpene resins, and oil-based hydrocarbon resins are used. Other tackifying resins can also be used as the tackifying resin of the composition if they have good compatibility with the block copolymer and do not deteriorate processability. The block copolymer used in the present invention can be blended with other polymers as long as it does not impair the spirit of the present invention. Usable polymers include NR, IR, BR, SBR, and EPDM. Butyl rubber or low molecular weight isoprene and butadiene rubber, imprene-butadiene copolymers, aromatic vinyl-conjugated diene block copolymers and their hydrogenated products, ethylene-vinyl acetate copolymers, polyesters, etc. Examples include thermoplastic resins and thermoplastic polyurethanes. The proportion of these polymers used is 100% block copolymer.
The amount per part by weight is preferably approximately 20 parts by weight or less. The block copolymer used in the present invention may be crosslinked. Sulfur, peroxide, etc. can be used as the crosslinking agent. Crosslinking can be easily carried out by conventional methods and equipment used for conventional rubber crosslinking. The amount used is 0.5 to 20 parts by weight of sulfur and 0.5 to 20 parts by weight of peroxide per 100 parts of block copolymer.
1 to 20 parts by weight is suitable. In the present invention, the lamination of the block copolymer and the metal plate is
A method in which the block copolymer is shaped into a film and then sandwiched between heated metal plates, a method in which the molten block copolymer is coated on a metal plate using a roll coater and then sandwiched, or a method in which the block copolymer is melted This is done by extruding it and sandwiching it between metal plates, etc. The metal plate used in the present invention is not particularly limited as long as it functions as a vibration damping plate, but cold-rolled steel plates,
In addition to steel plates such as carbon steel plates, stainless steel plates, and low alloy tempered plates, aluminum plates and the like can be cited.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples. Table 1 shows the formulation of the composition. The block copolymers used in the examples were obtained as follows. (Reference example) Cyclohexane as a solvent and TME as a vinylating agent in a stirred autoclave purified with dry nitrogen.
DA, 5ec-Boff was charged as an initiator, styrene monomer was fed at a temperature of 50°C, then isoprene was fed, and then styrene monomer was fed, and after polymerization, the reaction was stopped. The obtained reaction solution was poured into methanol to recover the block copolymer. The number average molecular weight of the obtained block copolymer (A) determined by GPC is 2.0OX10'. The molecular weight of the styrene block is 1.00X10', and the vinyl bond content of the isoprene block determined by NMR is 71.9%. Met.

[Examples 1 to 5 and Comparative Example 1] The block copolymer (A) was used to prepare the blends shown in Table 1, and the mixture was made into a sheet having a width of 2.5 am, a length of 40 cm, and a thickness of 0.5 am.
A test piece was made by sandwiching it between 8 m cold-rolled steel plates with a thickness of 0.02 mm, and the loss coefficient was measured using a cantilever resonance method. The shear adhesive strength was measured in accordance with JIS-6850. The results of these measurements are shown in Table 2. Further, the temperature dependence of the loss coefficient η is shown in FIG.
As can be seen from Table 2 below, the loss coefficient ηΦ value of all samples is higher than that of the comparative example (11), indicating that the ethylene sample has excellent vibration damping performance near room temperature. - In Example (4) in which vinyl acetate was blended, an improvement in adhesion to metal was observed. In addition, for Examples (3), (4) and Comparative Example (11), samples equivalent to those used for loss coefficient measurement were observed. A bending test (R = 4 mm) was conducted using the elastomer to investigate peeling and extrusion of the elastomer.As a result, peeling occurred in Comparative Example (1), but peeling did not occur in Examples (3) and (4). , none of the extrusion occurred.

Example 6 Hydrogenated product CB) was obtained by hydrogenating the block copolymer (A) using Pd-C. As for the iodine value of the hydrogenated product (B), the hydrogenation rate was 90%. Using this, the same test as for block copolymer (A) was conducted. The measurement results were almost the same as when using the block copolymer (A).

【Effect of the invention】

A vibration-damping composite produced using a composition containing the block copolymer of the present invention has excellent vibration-damping performance and can also be subjected to drawing and bending.

[Brief explanation of drawings]

FIG. 1 shows the temperature dependence of the loss coefficient η for the test pieces obtained in Examples 1 to 5 and Comparative Example 1.

Claims (1)

[Claims] (1) Two or more blocks consisting of a vinyl aromatic monomer with a number average molecular weight of 2,500 to 40,000, a number average molecular weight of 10,000 to 200,000, a vinyl bond content of 40% or more, and a main body of tan δ at 0°C or higher. Consisting of isoprene or isoprene-ptadiene having a dispersion peak, or one or more blocks consisting of a hydrogenated product thereof, with a molecular weight of 30,000 to 3,000
A vibration-damping metal composite formed by laminating a composition comprising a block copolymer of 0.00.