JPH02135256A - Composition having excellent vibration-damping performance - Google Patents

Abstract

PURPOSE:To provide a composition composed of a specific block copolymer and a tackifier resin having a specific softening point, having sufficiently high mechanical strength and elongation, exhibiting excellent vibration-damping performance and having good adhesivity to metal and moldability. CONSTITUTION:The objective composition is produced by compounding (A) 100 pts.wt. of a block copolymer having a molecular weight of 30,000-200,000, preferably 40,000-150,000 and composed of (A1) two or more blocks composed of an aromatic vinyl monomer (preferably styrene) and having a number-average molecular weight of 2,500-30,000 and (A2) one or more blocks composed of isoprene or isoprene-butadiene, containing >=40% of vinyl bond and having a main dispersion peak of tandelta at >=0 deg.C, (B) 5-250 pts.wt. of a tackifier resin (e.g., terpene resin) having a softening point of >=30 deg.C and, as necessary, (C) other polymers, plasticizers, softeners, fillers (preferably mica), etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a composition comprising a novel block copolymer and a tackifier resin, which has excellent vibration damping performance.

[Problems to be solved by conventional techniques and inventions] In recent years,
BACKGROUND OF THE INVENTION With the development of transportation such as automobiles, the noise and vibration caused by them have become a major social problem. Furthermore, with the spread of various types of office equipment, the vibrations and noise generated by these equipment have become a major problem.

Furthermore, even household electrical appliances such as refrigerators, washing machines, and vacuum cleaners are required to be quieter. Conventionally, various springs, anti-vibration rubbers, etc. have been used to reduce or eliminate this vibration and noise f. Among these, the vibration isolating beam has been widely used because of its shape selectivity, vibration isolation properties in a high frequency range, and low cost. Also, recently, steel plates with an allocation function, to which various viscoelastic bodies are attached or sandwiched, have begun to be used.

Rubbers such as natural rubber, styrene-butadiene rubber, butylpum, etc. have been used for this purpose, but when using these materials, various compounding agents are blended to develop sufficient mechanical strength. Then, it is necessary to crosslink this by a method such as vulcanization. Moreover, many steps are required to create the formulation, and the crosslinking reaction also requires a long time and energy.

In addition, when used in combination with a steel plate, a material with high elongation is preferable when processing such as bending or drawing, and from this point of view, the earlier Pum type material is preferable, but at the same time it has the above-mentioned drawbacks. It also has the disadvantage of insufficient adhesion to steel plates, making its application difficult.

The present invention not only has sufficient mechanical strength and elongation, but also exhibits excellent vibration damping performance, has excellent adhesion to members such as metal, and can be extremely easily molded by hot melt. The object of the present invention is to provide a composition that does not require crosslinking and has excellent workability.

[Means to solve the problem]

According to the present invention, the above-mentioned problem can be solved by containing a block consisting of two or more vinyl aromatic monomers having a number average molecular weight of 2,500 to 30,000 and one or more vinyl bonding metals having a number average molecular weight of 40,000 to 40,000.
1 or more and has a molecular weight of 30,000 to 200 and is composed of a block consisting of isogrene or isoprene-butadiene having a main dispersion peak of tan δ at 0 ° C. or more.
100 parts by weight of a block copolymer of 000, and 3
The problem is solved by a composition with excellent distribution performance, which is composed of 5 to 250 parts by weight of a tackifying resin having a softening point of 0° C. or higher.

The above block copolymer exhibits strength equivalent to vulcanized copolymer without crosslinking because the vinyl aromatic blocks form pseudo-crosslinking points, and is also elastic due to the presence of isogrene or isoprene-butadiene blocks. It has the properties of a body. The composition comprising the present block copolymer and tackifying resin can be hot-melted and is extremely easy to mold, and also has excellent adhesiveness to members such as metals and f-lastics.

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,
Examples, t-styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, 3-methylstyrene, 4-f-ropylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl) ) Styrene, etc., but styrene is the most preferred.

Further, isoprene or isoprene-butadiene is suitable as the second component of the block copolymer used in the present invention. When using other 7-mers, for example, when butadiene is used alone, even if the amount of vinyl bond is increased, the temperature at which damping performance is exhibited is less than 0°C, and the function at the temperature actually used is not obtained. It is of little practical significance.

In the case of isogrene, by adding the vinyl bond of the present invention, it can exhibit its full vibration damping performance in a practical temperature range from approximately 0°C to around 50°C, making it applicable to a wide range of applications. This is extremely meaningful in practical terms. In the case of isoprene-butadiene, if the proportion of isoprene is 40% or more, vibration damping performance is exhibited at 0° C. or higher. The forms of the copolymer are random, block, and TCJ? The vinyl bond content of the isogrene or imprene-butadiene block portion of the block copolymer used in the present invention is 40% or more (may be 100%). If the vinyl bond content is less than 401, sufficient allocation 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. Even if there is a peak only at a temperature lower than 0°C, sufficient allocation performance cannot be obtained in the normal temperature range. Note that when the vinyl bond content of the isogrene block is 100%, the tan δ absorption temperature is 60°C, so the possible upper limit is 60°C.

The molecular weight of the block copolymer obtained is 30,000 to 2.
It must be in the range 00000. molecule i is 3
If it is less than 0,000, the mechanical properties such as strength and elongation at break of the block copolymer itself will decrease.

If it exceeds 200,000, workability deteriorates.

From this point of view, the molecular weight of the block copolymer is more preferably in the range of 40,000 to 150,000.

The molecular cap of vinyl aromatic block is 2500-30000
If the molecular weight is less than 2,500, the mechanical performance will deteriorate, and if it exceeds 30,000, 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, and conversely, 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 block form of the block copolymer is A(BA)n.

(AB)n, where one is an aromatic vinyl hexamer.
B is isoprene or isoprene-
It represents a block consisting of butadiene, and n is an integer of 1 or more.

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-butanoene is sequentially polymerized using an alkyllithium compound as an initiator, or a method in which an aromatic vinyl compound, isogrene or isogrene-butanoene is polymerized and coupled with a coupling agent, or dilithium is used as an initiator. Examples include a method of sequentially polymerizing isoprene, isogrene-butadiene, or an aromatic vinyl compound using a system 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. As the coupling agent, dichloromethane, dibromomethane, dichloroethane, dibromoethane, etc. are used.

Examples of dilithium compounds include naphthalene dilithium,
Examples include oligostyryl dilithium and solithiohexylbenzene. 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 coupling agent, based on 100 parts by weight of all monomers used in the polymerization.

In order to make the microstructure of the isoprene or isozolene-butadiene moiety such that the vinyl bond has a width of 40°C or more and a peak of the main dispersion of t-nδ at 0°C or higher, it is necessary to A Lewis base is used as a cocatalyst. Examples of Lewis bases include ethers such as dimethyl ether, diethyl ether, methyl ethyl ether, and tetrahydrofuran;
Glycol ethers such as ethylene glycol diethyl ether and ethylene glycol diethyl ether, N,
N,N',N'-tetramethylethylenediamine (T
MEDA), tertiary amines such as triethylenediamine, and ether-containing amines such as N-methylmorpholine and N-ethermorpholif.

Lewis base is 0.1 to 400 parts per 100 parts by weight of initiator.
Use parts by weight.

An inert organic solvent is used as the solvent. In particular carbon hydrogens 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 used.

Regardless of the polymerization method used, the polymerization is carried out at a temperature of -20 to 80°C for a period of 1 to 50 hours.

Block copolymers can be produced by adding the polymerization solution to a poor solvent such as methanol, coagulating it, then drying it by heating or under reduced pressure, or by dropping the polymerization solution into boiling water to azeotrope the solution and agent, and then heating it. Alternatively, it can be obtained by drying under reduced pressure.

Next, as for the tackifying resin which is another essential component of the present invention, a resin having a softening point of 30 DEG C. or higher is added in an amount of 5 to 250 parts by weight based on 100 parts of the block copolymer. Examples of tackifying resins include terpene resins, terpene-phenol resins, rosin resins, hydrogenated rosin resins, synthetic polyterpenes, aromatic hydrocarbons, aliphatic hydrocarbons, alicyclic hydrocarbons, etc. Examples include petroleum-based hydrocarbon resins. In the present invention, the tackifying resin must have a softening point of 30°C or higher; if the softening point is lower than 30°C, the mechanical strength of the composition containing it will decrease;
Moreover, adhesiveness is not sufficiently developed, which is not preferable.

The tackifier resin is used in an amount of 5 to 250 parts by weight based on 100 parts by weight of the block copolymer.

If the amount used is less than 5 parts by weight based on the block copolymer, the effect of improving adhesion will be poor, and if it exceeds 250 parts by weight, mechanical strength will decrease, which is not preferable. From this point of view, the amount used is more preferably in the range of 10 to 150 parts by weight.

The composition of the present invention can be easily hot melt processed. That is, a molded product is obtained by kneading with a kneader or the like, molding with a press or the like, or kneading and molding with an extruder, and usually cooling.

The composition of the present invention can be used by itself as a molded product, but in some cases, it can also be blended with other polymers and used as a composition to the extent that it does not impair the spirit of the present invention. Other I remers to be blended include NR,
IR, BR, SBR, EPDM.

Thermoplastic resins such as EPR, butyl rubber or low molecular weight isoprene, butadiene rubber, isogrene-sitatsuene copolymers, aromatic vinyl-conjugated diene block copolymers, ethylene, vinyl acetate copolymers, polyamides, polyesters, etc. Examples include plastic polyurethane. The blending ratio of these is preferably approximately 20ii parts or less per 10014 parts of block copolymerization in the present composition.

The composition of the present invention also contains compounding agents used in general rubber compounding, such as plasticizers and softeners such as oil, reinforcing agents such as carden black and silica, and fillers such as calcium carbonate, talc, and mica. be able to. In particular, mica is more preferably used since it can improve allocation performance.

The preferred amount of each compounding agent is usually 10% of the block copolymer.
0 parts by weight, 5 to 250 parts by weight of plasticizer/softener, 20 to 200 parts by weight of reinforcing agent, and 20 to 300 parts by weight of filler. The blending method may be the hot melt processing described above.

The composition of the present invention may be used after being crosslinked.

As the crosslinking agent, sulfur, . . . oxide, etc. are used. Crosslinking can be easily carried out using common methods and equipment used for conventional rubber crosslinking. The amount used is 0.00 sulfur per 100 ii part of the block copolymer.
Appropriate amounts are 5 to 20 parts by weight and 0.1 to 20 parts by weight of peroxide.

The composition of the present invention can be used as it is as a molded product, but
Since it has excellent adhesive properties, it is suitable for use in applications where it is attached to a metal plate or the like or when it is used by sandwiching it. The materials to be bonded together at this time include metals such as iron and aluminum; polystyrene, acrylic a
Hard plastics such as resin, ABS resin; and soft plastics such as polyethylene, polypropylene, polyvinyl chloride, etc.
Examples include f-lastics.

The following is an example of Ki-ni F! A will be explained more specifically.

Example 1 and Comparative Example 1 Cyclohexane 600.9% N, N, N', N'-tetramethylethylenediamine (TbrEDh) 2.9 and initiator n-BuLi 7 mmol were added to a dry autoclave purged with nitrogen. After raising the temperature to °C, styrene monomer was fed at 30F and polymerized for 1.5 hours. Then add isoprene to 14011. ．． 2.
Polymerization was carried out for 5 hours. Then again, styrene monomer 30
Ii was fed and polymerized for 1.5 hours. The obtained reaction solution was poured into a large amount of methanol to completely precipitate the product, and this was vacuum dried to obtain a block copolymer.

The number average molecular weight of the obtained block copolymer (A) was 51
000, the molecular weight of the styrene block was 5100, and the vinyl bond content tu of the isoprene block was 79.8%. In addition, when the tan δ of the 11H1 lever block copolymer was totally measured using a rheopipron, it was found to be 38.5.
It was found that the main dispersion peak was at °C.

A composition was prepared by melt-mixing the obtained copolymer at 180° C. according to the formulation shown in Table 1, and its impact resilience and adhesive strength to an iron plate were measured. To measure the adhesive strength, the composition was melted at 160°C on a degreased cold-rolled steel plate and applied to a thickness of 0.5 fin in an area of 5 x 5 crIL, and the two steel plates were bonded together while being molten at room temperature. It was cooled to 30 cm/cm using an Instron tensile tester.
This was done by measuring the shear adhesive strength at a speed of min. The results are shown in Table 1. It can be seen that the composition of the present invention has low impact resilience and excellent vibration damping performance, and at the same time, it has sufficient adhesive strength to the iron plate.

Table 1 Example 1 Blended block copolymer (A) Tackifying resin 1) Antiaging agent 2) Impact resilience 25°C (壬) 50'C Adhesive strength (kg μm2) Comparative example 1 1) Aliphatic sensitized carbonization Hydrogen 1 fat (softening point 100°C): manufactured by Arayo Kagaku ■, Alcon P-100 Tetrakis-[methylene-3-(3',5'-Z-ta)
rt-butyl-4'-hydroxyphenyl) clobionate] methane: Irganox 10 manufactured by Civer Geigy
10 Example 2 Block copolymers (B), (C), (D), (E) were prepared in the same manner as in Example 1, except that the amounts of n-BuL1s styrene and isoprene used were changed to those shown in Table 2. I got it. The properties of the obtained block copolymer were as shown in Table 2.

Using this block copolymer, a composition was prepared in the same manner as in Example 1 according to the formulation shown in Table 3, and its impact resilience and adhesive strength were measured. The results are shown in Table 3.

These results show that all of the compositions of the present invention have sufficient adhesive strength and excellent distribution performance.

Table 2 Table 3 Cyclohexane (9) 1-BuL% (mmol) with TMED (P) Styrene (I) (Isoprene (9> Styrene (n) (,9) 0.5 Molecule fit 39,000 Styrene Yuhi and Do Hisaku 3.4003.4 Bond amount (
H) 45.3 B of tan δ C) 7.0 0.5 78.000 5.900 65.3 23.1 126.000 15.900 80.4 41.5 1.0 0.3 158. 000 12.500 75.3 38.5 Block copolymer (B) (C) (D) (E) Tackifying resin 1) 1) Synthetic polycil resin (softening point 85°C): Nippon Zeon ■ Clayton U-1852) Tetrakis-[methylene-3-(3', 5'-di-t@rt-butyl-4
'-Hydroxyphenylgropionate]methane: Teva Geigy Irganox 1010 Example 3 and Comparative Example 2 8 g using the block copolymer (A) obtained in Example 1
A composition was prepared in the same manner as in Example 1 according to the formulation shown in Table 4, and its impact resilience and adhesion were evaluated. For comparison, the vinyl bond amount is 8 and the styrene content is 14.
Styrene-isoprene-styrene block copolymer (F) with a molecular weight of 176,000 (Krayton T manufactured by Shell Co., Ltd.
As shown in Table 4, the compositions of the present invention (&1 to 4) have low impact resilience and high adhesion to iron plates. On the other hand, when a block copolymer with a small amount of vinyl bonds is used, the adhesive force is sufficiently high, but the impact resilience is high, indicating that the splitting effect is small.

)゛X-d margin Table 4 AI A2 (Blend) Block copolymer) 100 Block copolymer (F) Tackifying resin 1) Antiaging agent 2) 1) Aliphatic cyclic hydrocarbon resin (European point 100°C ): Arayo Chemical [Homemade Alcon P-100 Tetrakis-[Methylene-3-(3',5'-theta
rt-Butyl-4'-hydroxyphenylzolopionate]methane: Irganox 101 manufactured by Chipa Geigy
0 Example 4 and Comparative Example 3 Using the block copolymer (A)'r obtained in Example 1, the formulations shown in Table 5 were prepared using tackifying resins (1) to (V) having different softening points. Therefore, a composition was prepared in the same manner as in Example 1, and its impact resilience and adhesiveness were evaluated. As shown in Table 5, the compositions (&1 to 4) of the present invention have low impact resilience and high adhesive strength to iron plates.

On the other hand, a formulation that uses all tackifying resins with a low Europeanization point of 20°C has high rebound resilience especially at high temperatures, indicating poor breakage performance, and at the same time only low adhesive strength can be obtained. It turns out there isn't.

Below A is white Table 5 Flat l (Composition) Block copolymer (A) Zo.

Tackifying resin ([)1) 75 〃(II)2) (Book 3) (Foundation) 1 (V)5) Anti-aging agent 6)1 Repulsion elasticity 25℃ (Re 50’C Adhesive strength (yu/cWL2) l) Terpene resin (ys lenone made from cheap crude oil) Softening point Zoo℃) PXlooOl (ys resin made by cheap crude oil IaOJ) Softening point 80℃) P.

800° (cheap crude oil ■ pear ys reson softening point 60°C) x 600. (Cheap crude oil @ pear YS resin softening point 40℃) x (Cheap crude oil ■ YS resin softening point 20℃) x 200. 6) Tetrakis-[methylene-3-(3',5'-notart-butyl-4'-hydroxyphenylpropionate]methane: Norganox 10 manufactured by Ciba Geigy)
10 [Effects of the Invention] The composition of the present invention not only has sufficient mechanical strength and elongation, but also exhibits excellent vibration distribution performance, has excellent adhesiveness to members such as metals, and can be extremely easily melted by hot melting. It can be molded and has excellent workability as there is no need for crosslinking.

Claims (1)

[Claims] (1) Two or more number average molecular weights in the molecule are 2500 to 3
Molecular weight composed of a block consisting of a vinyl aromatic monomer of 0,000 and a block consisting of isoprene or isoprene-butadiene in which the content of one or more vinyl bond metals is 40% or more and the main dispersion peak of tan δ is at 0°C or higher. 100 parts by weight of a block copolymer having a temperature of 30,000 to 200,000, and 5 to 250 parts by weight of a tackifier resin having a softening point of 30°C or higher.A composition having excellent vibration damping performance.