JP3422066B2 - Viscoelastic resin for vibration damping material and composition thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a viscoelastic resin for vibration damping materials and an adhesive composition having excellent properties.

[0002]

2. Description of the Related Art With the development of mechanical civilization such as motorization, noise is becoming higher and higher, and the demand for noise prevention is increasing. Under such circumstances, in recent years, a composite type vibration damping material in which a member having a vibration damping function is arranged in an intermediate layer has been developed. For example,
A composite type vibration damping material obtained by sandwiching a viscoelastic resin between two thin metal plates has a function of converting the vibration energy applied to the resin layer into heat energy to effectively damp the vibration. It has been studied to use it for a wide range of applications such as vibrators, stairs, doors, shutters, building materials such as flooring materials, automobile engine covers, oil pans, etc.

Conventionally, the viscoelastic material constituting the intermediate layer of the vibration-damping steel sheet has been a monomer such as vinyl acetate or vinyl chloride, vinyl acetate-ethylene copolymer, vinyl acetate-ethylene-acrylic acid. In addition to copolymers, copolymers of isocyanate prepolymers and vinyl monomers, polyurethanes (JP-A-47-19277)
No.), polyester (No. 50-143880), polyamide (No. 51-79146), cross-linked polyolefin (No. 59-152847) and the like are known. Further, a damping material using an epoxy resin such as diglycidyl ether of polyol or its polymer (see 63-186).
No. 795, JP-A-3-121120, etc.) are known.

[0004]

A composite type vibration damping material, particularly a viscoelastic resin used as an intermediate layer of a composite type vibration damping metal plate, has a vibration damping performance in a wide temperature range. High adhesion to boards, heat resistance, water resistance, weather resistance,
Oil resistance is required, but it is difficult to obtain each performance in good balance. For example, there have been various problems such that the vibration damping performance deteriorates when trying to obtain high adhesiveness and heat resistance, or the vibration damping performance can be exhibited only within a narrow temperature range. In recent years, thermosetting adhesives with high heat resistance and solvent-free adhesives have been required for workability and safety, but adhesives that meet each requirement and have excellent performance There is a problem that it is very difficult to obtain the drug.

The present inventors have conducted extensive research to solve the above technical problems. As a result, the inventors have completed the present invention by knowing that such a problem can be solved by interposing a vibration-damping adhesive containing a specific viscoelastic resin as a main component in a composite plate, particularly a metal plate. As is clear from the above description, the object of the present invention is to exhibit excellent vibration damping performance in a wide temperature range,
In addition, a viscoelastic resin for vibration damping materials, which exhibits high adhesion to adherends such as metal plates, and is also excellent in heat resistance and water resistance, and heat for solvent-free vibration damping materials containing the resin as an active ingredient. A curable adhesive composition is provided.

[0006]

The present invention has the following constitutions (1) to (5). (1) A diol represented by the formula HO-R-OH (in the formula, R is an alkylene group having a side chain of an alkyl group and having 2 to 12 hydroxyl groups and having 2 to 12 carbon atoms) and a dicarboxylic acid Polyester diol obtained by condensing has 30 carbon atoms
A viscoelastic resin for a vibration damping material, comprising a polyester obtained by reacting one or more acid anhydrides selected from the following aromatic acid anhydrides. (2) The viscoelastic resin for a vibration damping material according to item (1), which is made of polyester obtained by reacting the acid anhydride / polyester diol at a molar ratio of 1.5 to 3. (3) The viscoelastic resin for vibration damping materials according to item (1) or (2), wherein the aromatic acid anhydride having 30 or less carbon atoms is trimellitic acid anhydride or pyromellitic acid anhydride. (4) The number average molecular weight of the polyester is 1000 to 20.
The viscoelastic resin for vibration damping material according to any one of (1), (2) or (3), wherein the viscoelastic resin is 000. (5) A composition for a composite damping material, which comprises 100 parts by weight of the viscoelastic resin according to the item (1) and 1 to 100 parts by weight of an epoxy resin and 0.1 to 10 parts by weight of a curing accelerator.

The structure and effects of the present invention will be described in detail below. In the formula of the present invention, HO-R-OH (in the formula, R has an alkyl group side chain and the main chain connecting two hydroxyl groups has 2 carbon atoms.
Examples of the diol component represented by alkylene group of 1 to 12) include 1,2-propanediol, 1,3-butanediol, neopentyl glycol and 3-methyl-
1,5-pentanediol, 2-methyl-2,4-pentanediol, 2-ethyl-2-methyl-1,3-propanediol, 2-ethyl-2-pentyl-1,3-propanediol, 2- Ethyl-2-hexyl-1,3-
Propanediol, 2,2-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2-n-butyl-2-hexyl-1,
3-propanediol, 2-methyl-2-propyl-
1,3-propanediol, 2-pentyl-2-propyl-1,3-propanediol, 2-ethyl-1,3-
It is one or more diols selected from hexanediol and the like. Saturated / unsaturated diols having no alkyl group side chains can be mixed in a range of less than 20 mol% of all diols, but when saturated / unsaturated diols having no side chains are excessive, vibration is suppressed over a wide temperature range. The performance may not be obtained.

Examples of the dicarboxylic acid component in the present invention include aliphatic dicarboxylic acid, aromatic dicarboxylic acid, unsaturated aliphatic and alicyclic dicarboxylic acid, and the like. Aliphatic dicarboxylic acid is 80 mol in the component. % Or more is preferable. 80 mol% of aliphatic dicarboxylic acid
If it is less than the above, the vibration damping performance may be lowered depending on the diol used. Examples of the aliphatic dicarboxylic acid include succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid. Examples of the other dicarboxylic acid include terephthalic acid, isophthalic acid, orthophthalic acid, phthalic anhydride, naphthalic acid, biphenyldicarboxylic acid, hexahydro (anhydrous) phthalic acid, cyclohexanedicarboxylic acid, 5-methylisophthalic acid, fumaric acid, maleic acid. , Itaconic acid and the like.

The polyester in the present invention can be obtained by esterification reaction of a diol and a dicarboxylic acid by a known method. The number average molecular weight of polyester is 1
2,000 to 20,000, preferably 2,000 to 15,000, and if less than 1,000, the vibration damping performance is deteriorated.
If it is larger than this, it becomes difficult to handle without a solvent.

The acid anhydride used in the present invention has 30 carbon atoms.
The following aromatic acid anhydrides. Specific examples thereof include trimellitic anhydride, pyromellitic dianhydride, 3,3 ′, 4.
4'-benzophenone tetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride,
Examples thereof include bis (3,4-dicarboxyphenyl) ether dianhydride and 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride. Of these, trimellitic anhydride and pyromellitic dianhydride are particularly preferable.

The viscoelastic resin for damping material in the present invention is
It is obtained by reacting the polyester diol synthesized as described above with an acid anhydride. The acid anhydride / polyester diol molar ratio is particularly preferably in the range of 1.5 to 3. If the reaction molar ratio is less than 1.5, the resin may not be obtained in liquid form, and even if it is obtained in liquid form, the adhesiveness may be deteriorated. On the other hand, if it is larger than 3, the vibration damping performance may not be obtained in a wide temperature range, and the vibration damping property itself may be deteriorated.

Examples of the epoxy resin in the present invention include bisphenol A type epoxy resin, bromine-containing epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, urethane modified epoxy resin,
Examples thereof include phenol and cresol type epoxy resins, novolac type epoxy resins, cycloaliphatic epoxy resins, glycidyl ester resins, glycidyl amine resins, and heterocyclic epoxy resins. The epoxy resin is
They can be used alone or as a mixture of two or more.

As the curing accelerator in the present invention, those having a latent property are preferable, for example, dicyandiamide, organic acid dihydrazide, tertiary amine salt, imidazole salt,
Examples thereof include Lewis acid salts and Bronsted acid salts. Preferred are dicyandiamide, tertiary amine salts, and imidazole salts.

The composition of the composite type vibration damping material of the present invention comprises 1 to 100 parts by weight of an epoxy resin and 0.1 part by weight of a curing accelerator based on 100 parts by weight of the viscoelastic resin according to claim 1.
It is obtained by blending 10 to 10 parts by weight.

If necessary, for example, a silane coupling agent, an antioxidant, an inorganic additive, a viscosity modifier, and a viscosity modifier may be added to the adhesive of the present invention. Specifically, the silane coupling agent is not particularly limited and may be a commercially available one, but it is particularly effective if the organic functional group has an amino group or an epoxy group. For example, as a commercially available product, Amino-based Sila Ace S330,
For epoxy type, Sila Ace S510 (above, Chisso)
And so on. As the antioxidant, an amine-based compound, a phenol-based compound, a quinone-based compound or the like is used. The inorganic additive is preferably in powder form, and examples thereof include alumina, silica, calcium carbonate, mica, talc, kaolin, glass fiber, metal fiber and various metal powders. Viscosity modifiers include diluents such as reactive diluents, non-reactive diluents, fillers, thickeners such as high viscosity polymers. Examples of the viscosity adjusting agent include thixotropic agents, leveling agents, defoaming agents, and adhesives. Further, the adhesive of the present invention is characterized by being a solvent-free liquid adhesive, but it goes without saying that a diluting solvent can be used if necessary.

As described above, the present invention has the formula HO-R-OH (wherein
R is an alkylene group having an alkyl group side chain and having 2 to 12 carbon atoms in the main chain connecting two hydroxyl groups) and a polyester diol obtained by polycondensing a diol and a dicarboxylic acid, and having 30 or less carbon atoms. A viscoelastic resin for vibration damping materials, which comprises a polyester obtained by reacting one or more acid anhydrides selected from the aromatic acid anhydrides described above, or an epoxy resin, a curing accelerator, and, if necessary, the viscoelastic resin. The purpose of the present invention is to provide a quick-curing, solventless thermosetting vibration-damping adhesive that is excellent in adhesiveness, heat resistance, water resistance, and has high vibration-damping performance over a wide temperature range by incorporating various additives. .

[0017]

The present invention will be specifically described with reference to the following examples. In this example, a composite vibration-damping metal plate was manufactured under the following conditions, and the performance of each composite was evaluated by using them as samples.

Production of composite type vibration damping metal plate Acetone degreased galvanized steel plate having a thickness of 0.4 mm is coated with the adhesive shown in the embodiment by a bar coater or a doctor blade so that the thickness becomes 50 μm. Steel sheets of the same kind that had not been applied were laminated and pressure-bonded by a roll. This laminated steel plate was heated in an oven at 200 ° C. for 5 minutes to obtain a composite vibration-damping metal plate (damping steel plate).

Adhesion Test T-Peel Strength: According to JIS K 6854. Tensile speed 50 mm / min. Shear strength: According to JIS K 6850. Tensile speed 5 mm / min.

Vibration damping measurement A frequency of 50 at room temperature to 100 ° C. by the cantilever method.
The loss coefficient [η] at 0 Hz was measured.

Heat Resistance Test Each composite type vibration damping metal plate was heated in an oven at 200 ° C. for 30 minutes and then subjected to an adhesion test at room temperature.

Water resistance test After immersing each composite type vibration damping metal plate in boiling water for 24 hours,
The adhesion test was performed at room temperature.

(Synthesis Examples 1 and 2) In a reactor 1 equipped with a thermometer, a stirrer, a nitrogen introducing tube, and a condenser, 2-n-butyl-2-ethyl-1,3-propanediol 1603 was added.
g, 1564 g of adipic acid, and 0.2 g of a catalyst antimony trioxide were added, and the reaction was carried out at 195 to 220 ° C. for 20 hours under a nitrogen stream under atmospheric pressure to obtain a polyester diol having a number average molecular weight of 4000. This polyester diol 100
g and 12 g of pyromellitic dianhydride were charged in a reactor 2, 0.15 g of N-benzyl-2-methyl-imidazole was added as a catalyst, and the mixture was reacted at room temperature to 100 ° C. for 3 hours to obtain a viscoelastic resin. A viscoelastic resin of Synthesis Example 2 was obtained by the same production method, and the results thereof are also shown in Table 1.

[0024]

[Table 1]

(Comparative Synthesis Example 1) 100 g of a polyester diol having the same number average molecular weight of 4000 as in Synthesis Example 1 and 12 g of isophorone diisocyanate were charged in a reactor, and 0.15 g of tin octylate was added as a catalyst, followed by 3 at 95 ° C.
The reaction was carried out for a time to obtain a viscoelastic resin, and the results are shown in Table 1.

(Comparative Synthesis Example 2) 901 g of 1,4-butanediol, 1564 g of adipic acid and 0.2 g of catalyst antimony trioxide were placed in a reactor 1 equipped with a thermometer, a stirrer, a nitrogen introducing tube and a condenser, and nitrogen was added. Air flow, under normal pressure, 19
The reaction is carried out at 5 to 220 ° C for 20 hours, and the number average molecular weight is 40.
00 polyester diol was obtained. 100 g of this polyester diol and 12 g of pyromellitic dianhydride were charged in a reactor 2, 0.15 g of N-benzyl-2-methyl-imidazole was added as a catalyst, and the mixture was reacted at room temperature to 100 ° C. for 3 hours to obtain a viscoelastic resin. The results are shown in Table 1.

(Examples 1 to 4) and (Comparative Examples 1 and 2) Each of the viscoelastic resins obtained in Synthesis Examples 1 and 2 and Comparative Synthesis Examples 1 and 2 was mixed with an epoxy resin, a curing accelerator and the like. It was a liquid adhesive. Using this adhesive, a composite vibration-damping metal plate (damping steel plate) was manufactured by the method described in Examples, and an adhesiveness test, vibration-damping measurement, heat resistance test, and water resistance test were conducted. The results are shown in Table 2.

[0028]

[Table 2]

[0029]

EFFECTS OF THE INVENTION Exhibiting excellent vibration damping performance in a wide temperature range, and exhibiting high adhesive force to an adherend such as a metal plate,
Further, it has become possible to provide a viscoelastic resin for vibration damping materials having excellent heat resistance and water resistance, and a solvent-free thermosetting adhesive composition for vibration damping materials using the resin.

Claims (5)

(57) [Claims] 1. The formula HO-R-OH (wherein R has an alkyl group side chain and the main chain connecting two hydroxyl groups has 2 to 1 carbon atoms).
2 alkylene group) and a polyester diol obtained by polycondensing a dicarboxylic acid with one or more acid anhydrides selected from aromatic acid anhydrides having 30 or less carbon atoms. Viscoelastic resin made of polyester for vibration damping materials. 2. The viscoelastic resin for a vibration damping material according to claim 1, wherein the viscoelastic resin comprises a polyester obtained by reacting the acid anhydride / polyester diol at a molar ratio of 1.5 to 3. 3. The viscoelastic resin for a vibration damping material according to claim 1, wherein the aromatic acid anhydride having 30 or less carbon atoms is trimellitic anhydride or pyromellitic anhydride. 4. A polyester having a number average molecular weight of 1,000.
The viscoelastic resin for a vibration damping material according to any one of claims 1, 2 and 3, wherein 5. 100 parts by weight of the viscoelastic resin according to claim 1, 1 to 100 parts by weight of an epoxy resin, and 0.1 parts by weight of a curing accelerator.
A composition for a composite vibration damping material, which comprises 10 to 10 parts by weight.