JPH06184512A - Vibration-damping thermosetting adhesive and vibration-damping composite board - Google Patents

Abstract

PURPOSE:To obtain an adhesive which is excellent in heat resistance, vibration- damping properties, and adhesiveness by compounding a heat-resistant epoxy resin with a specific amine adduct as a curative. CONSTITUTION:This adhesive is obtd. by compounding a heat-resistant epoxy resin (e.g. Epikote 828, a product of Yuka-Shell) with an amine-terminated amine adduct as a curative. This adduct is obtd. by reacting a polyester diol obtd. pref. by reacting 2-n-butyl-2-ethyl-1,3-propanediol with a dicarboxylic acid component contg. at least 80mol% aliph. dicarboxylic acid (e.g. adipic acid) with an arom. diisocyanate (e.g. diphenylmethane diisocyanate) and reacting the resulting isocyanate-terminated prepolymer with a diamine (e.g. 4,4'- diaminodiphenyl sulfone) in a molar ratio of the diamine to the prepolymer of 2 or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping material adhesive and a damping composite plate. More specifically, it relates to a thermosetting vibration-damping adhesive and a composite vibration-damping metal plate.

[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 homopolymer 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, polyesters (JP-A-50-14388)
No. 0), polyamide (JP-A-51-79146), cross-linked polyolefin (JP-A-59-152847).
JP), JP-A-47-19277, JP-A-63-202613, JP-A-1-16.
No. 8720) is known. In particular, JP-A-63
In JP-A-202613 and JP-A No. 1-168720, a NCO-terminated prepolymer is polymerized with a diamine or the like as a chain extender (number average molecular weight 8000 to 100000).
A thermoplastic urethane type vibration damping resin has been proposed.

[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 adhesiveness to plates and heat resistance are required. Thermoplastic resin and thermosetting resin are used for the viscoelastic resin depending on the application of the composite vibration-damping metal plate.However, in the case of thermosetting resin that is generally excellent in heat resistance, It is required to cure the resin according to the production line speed, and the curing time is within 5 minutes, preferably within 2 minutes. In the case of a thermosetting resin, a viscoelastic resin is mixed with a crosslinking agent or a curing agent, so that the storage stability of one liquid is poor and the pot life becomes short. Therefore, the crosslinking agent or the curing agent is separated from the viscoelastic resin. The method of mixing and using just before use is taken, and there is a problem in workability. In addition, it is difficult for viscoelastic resin to obtain various properties (vibration damping, adhesiveness, heat resistance, handling conditions, etc.) in a well-balanced manner. For example, when trying to obtain high adhesion and heat resistance, vibration damping performance decreases. In addition, there have been various problems such that when the resin is cured rapidly, the vibration damping performance can be exhibited only within a narrow temperature range and the vibration damping performance is deteriorated.

The present inventors have conducted extensive research to solve the above technical problems. As a result, an adhesive having an amine adduct (E) having vibration damping performance, a heat-resistant epoxy resin (F) and a curing accelerator (G) as essential components is interposed between two plate-shaped members, particularly metal plates. Thus, the inventors have completed the present invention, knowing that such problems can be solved. 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, to exhibit high adhesive strength to an adherend such as a metal plate, and to have high heat resistance and high speed. Hardness 1
It is to provide a thermosetting adhesive that can be used as a three-part liquid.

[0006]

The present invention has the following constitutions (1) to (7). (1) A diamine (D) is reacted with a prepolymer (C) having an isocyanate group terminal obtained by reacting a polyester diol (A) with an aromatic diisocyanate (B) at a reaction molar ratio of (D) / (C) ≧ 2. A thermosetting vibration-damping adhesive having excellent heat resistance, which is obtained by using the resulting amine adduct (E) having an amino group as a curing agent for a heat-resistant epoxy resin (F). (2) Polyester diol (A) is 2-n-butyl-2-ethyl-1,3-propanediol (abbreviated as DM).
H) is reacted with a dicarboxylic acid containing 80 mol% or more of an aliphatic dicarboxylic acid, the above (1)
The thermosetting vibration-damping adhesive described. (3) The number average molecular weight of the amine adduct (E) is 4000.
The thermosetting vibration-damping adhesive according to (1) above, which is ˜7000. (4) The thermosetting vibration-damping adhesive according to (1) above, wherein a diamine having a low reaction rate is used as the diamine (D). (5) The diamine (D) is added to the isocyanate group-terminated prepolymer (C) obtained by reacting the polyester diol (A) with the aromatic diisocyanate (B) at a reaction molar ratio of (D) / (C) ≧ 2. And a heat-resistant epoxy resin (F) and a curing accelerator (G) as essential components, which can be used as one liquid, and can be used as one liquid. Damping adhesive. (6) The diamine (D) is added to the isocyanate group-terminated prepolymer (C) obtained by reacting the polyester diol (A) with the aromatic diisocyanate (B) at a reaction molar ratio of (D) / (C) ≧ 2. 2 plates of a thermosetting type vibration-damping adhesive having excellent heat resistance, which is obtained by using the resulting amine adduct (E) having an amino group as a curing agent for a heat-resistant epoxy resin (F) Which is an intermediate layer of the plate-shaped member, and is a composite plate having vibration damping performance in a wide temperature range obtained by curing the adhesive. (7) The diamine (D) is added to the isocyanate group-terminated prepolymer (C) obtained by reacting the polyester diol (A) with the aromatic diisocyanate (B) at a reaction molar ratio of (D) / (C) ≧ 2. And a thermosetting epoxy resin (F) and a curing accelerator (G), which are amino groups at the end, are used as one component and can be used as one liquid. A composite plate having a vibration-damping adhesive as an intermediate layer between two plate-shaped members and hardening the adhesive to have a vibration-damping performance in a wide temperature range.

The structure and effects of the present invention will be described in detail below. The polyester diol (A) in the present invention is obtained by the reaction of glycol and dicarboxylic acid, and the glycol component has DMH having an alkyl group side chain with 6 carbon atoms.
Is used. Damping performance is low with saturated and unsaturated glycols that do not have an alkyl group side chain, and have an alkyl group side chain with less than 6 carbon atoms such as neopentyl glycol and 2,2-diethyl-1,3-propanediol. With glycol, the vibration damping performance at around room temperature decreases. An alkyl group side chain having 7 or more carbon atoms, for example, 2-n-pentyl-2-n
-Propyl-1,3-propanediol and the like have high vibration damping performance over a wide temperature range, but the adhesiveness decreases. 80 mol% or more of the dicarboxylic acid component of the polyester diol (A) is composed of an aliphatic dicarboxylic acid, and examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, azelaic acid and sebacic acid. Examples of the dicarboxylic acid component include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and orthophthalic acid, and unsaturated aliphatic and alicyclic dicarboxylic acids such as fumaric acid, maleic acid, itaconic acid and tetrahydrophthalic acid. . The number average molecular weight of the polyester diol (A) in the present invention is 3000 to 6000, preferably 4000 to 5000, and if it is less than 3000, the vibration damping performance is reduced, and if it is greater than 6000, the adhesiveness is reduced.

The aromatic diisocyanate (B) used in the present invention includes 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate (abbreviated as TD).
I), diphenylmethane diisocyanate (abbreviation MD)
I) and the like, and preferably MDI. The heat resistance of the aliphatic diisocyanate and the alicyclic diisocyanate decreases.

The diamine (D) used in the present invention is a diamine having a low reaction rate with isocyanate,
3,3′-dichloro-4,4′-diaminodiphenylmethane (abbreviation MOCA), 3,3′-diaminodiphenylsulfone (abbreviation 3,3′-DDS), 4,4′-diaminodiphenylsulfone (abbreviation 4,4) '-DDS),
3,3 ', 5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3', 5,5'-tetraethyl-4,4'-diaminodiphenylmethane, 3,3 ',
5,5'-tetraisopropyl-4,4'-diaminodiphenylmethane, 3,3'-diisopropyl-5,5 '
-Dimethyl-4,4'-diaminodiphenylmethane,
3,3'-diisobutyl-5,5'-diethyl-4,
4'-diaminodiphenylmethane, 3,3'-di-t-
Butyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane, 4,4 '-(diisopropylamino)-
Examples include diphenylmethane. A diamine having a high reaction rate with isocyanate, such as ethylenediamine, p-diaminobenzene, m-diaminobenzene,
When 4,4'-diaminodiphenylmethane or the like is used, it becomes unusable when it is stored in a liquid 1 in which an epoxy resin (F) and a curing accelerator (G) are mixed and the viscosity becomes high or gels in several hours to several days. . Diamine, which has a low reaction rate with isocyanate, can be stored in one solution for 10 days to 6 months, especially MOCA, 3,3'-DDS, 4,4'-D.
With DS, it is possible to store a single liquid for a long period of 3 to 6 months.

The amine adduct (E) of the present invention comprises a prepolymer (C) and a diamine (D) in a reaction molar ratio (D) /
It is obtained by reacting (C) ≧ 2. When (D) / (C) <2, the diamine becomes a chain extender and polymerizes. Polymerized polyurethane-urea resin has a reduced function as a curing agent for epoxy resin,
Longer curing time. When an excess molar amount of diamine (D) is used in the reaction, monomeric diamine remains in the amine adduct (E), which acts as a curing agent for the epoxy resin. However, when the monomer diamine is present in a large excess, the adhesiveness and the vibration damping performance are deteriorated, so the reaction molar ratio of the diamine (D) is preferably 2 ≦ (D) / (C).
≦ 5 is preferable. The number average molecular weight of the amine adduct (E) of the present invention is 4,000 to 7,000, preferably 5,000.
~ 6000. If the molecular weight is less than 4000, the vibration damping performance will be deteriorated, and if it exceeds 7,000, the quick-hardening property of the adhesive will be lost and the adhesiveness will also be decreased.

The heat-resistant epoxy resin (F) which can be used in the present invention is one or more epoxy resins selected from bisphenol A type epoxy resin, novolac type epoxy resin, urethane modified epoxy resin, etc. Examples include 828 (bisphenol A type, manufactured by Yuka Shell Co., Ltd.), DEN-438 (novolak type, Dow Chemical), ADEKA RESIN EPU-6 (urethane modified type, manufactured by Asahi Denka Co., Ltd.).

The curing accelerator (G) used in the present invention is
Aliphatic polyamines, amidoamines, polyamides, cycloaliphatic polyamines, aromatic polyamines, boron trifluoride amine complexes, tertiary amines, dicyandiamide and the like can be mentioned. Boron trifluoride amine complex which has little activity and exhibits high activity at 100 ° C. or higher is preferable. Most preferred is boron trifluoride benzylamine.

Diluting solvent (G) usable in the present invention
Is acetone, aniline, benzene, carbitol, carbon disulfide, carbon tetrachloride, cyclohexane, cyclohexanone, o-dichlorobenzene, diisobutyl ketone, ethyl acetate, n-heptane, n-hexane, isoamyl alcohol, isopropyl alcohol, methyl ethyl ketone ( Abbreviation MEK), methyl cellosolve, methyl amyl ketone, methyl isobutyl ketone, n-pentane, toluene, diethyl ketone (abbreviation DEK), dimethylformamide (abbreviation DMF), one or more solvents selected from ethyl acetoacetate, Preferably MEK, DEK, DM
A mixed solvent of F is preferable.

A silane coupling agent, an antioxidant and an inorganic additive can be added to the adhesive of the present invention, if necessary. The silane coupling agent that can be used in the present invention is not particularly limited and may be a commercially available one, but it is particularly effective if the organic functional group is an amino group or an epoxy group. For example, as a commercially available product, Sila Ace S330 for amino series and Sila Ace S51 for epoxy series
0 (above, Chisso) etc. can be mentioned. As the antioxidant that can be used in the present invention, amine compounds, phenol compounds, quinone compounds and the like are used. The inorganic filler that can be used in the present invention is preferably in powder form, such as alumina, silica, aluminum hydroxide, calcium hydroxide,
Examples thereof include mica and metal powder.

The material of the plate-like member that can be used for the composite plate of the present invention is not limited, and any material such as a metal plate, a wood plate, a stone plate, a glass plate or a plastic plate can be used. Further, the thickness thereof is not limited, and is equal to or more than a limit that can be configured as a plate-shaped member (for example, 0.1 mm or more in the case of a metal plate, preferably 0.3 mm or more) and is equal to or less than a limit of a thickness that can be used as a plate-shaped member (for example, if a stone plate is used. 50 mm or less, preferably 30 mm or less). Examples of the material of the metal forming the metal plate include iron, aluminum, stainless steel, titanium and the like. As the wood board material, cedar, rice cedar, cypress, oak, teak, lauan, and various other plywoods can be used.

The thermosetting vibration-damping adhesive (5) of the present invention is used as one liquid containing amine adduct (E), heat resistant epoxy resin (F) and curing accelerator (G) as essential components. It is a fast-curing adhesive with good storage stability, exhibits excellent vibration damping performance over a wide temperature range, and exhibits high adhesion and heat resistance to adherends such as metal plates.

[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.

Manufacture of composite type vibration damping metal plate Two 0.4 mm thick cold-rolled steel plates were degreased with acetone, and the adhesive shown in each example of the Examples was applied to one side of the two steel plates with a bar coater (# 50). ) Was used for coating. After drying these two steel plates in an oven (180 ° C / 1 min) and distilling off the solvent,
The two steel plates were laminated with the resin-coated side inside and thermocompression bonded (200 ° C./1 min) to obtain a composite vibration-damping metal plate.

Adhesion test T-Peel strength: Peel strength (kgf / 25 mm) when peeled at a speed of 50 mm / min with a tensile tester.

Vibration damping measurement A test piece of size 16 mm × 200 mm was measured at room temperature to
The loss coefficient [η] at a frequency of 250 Hz was measured in the temperature range of 140 ° C. The vibration control measuring device is a cantilever method (B
& K), FFT analyzer (DATA PHYSICS), vibration damping characteristic analysis software, shaker (Entec) were used in combination.

Heat Resistance Test Each composite vibration damping metal plate was heated in an oven at 180 ° C. for 30 minutes and then subjected to an adhesion test at room temperature.

Example 1 1.1 mol of DMH and 1.0 mol of adipic acid were used as an esterification catalyst, and antimony trichloride was added thereto to carry out an esterification reaction at 200 ° C. for 6 hours to obtain a polyester diol having a number average molecular weight of 4000. This polyester diol 80
While the mixture was added dropwise to 11 parts of MDI melted at 50 ° C (polyester diol was reduced in viscosity at 80 ° C in advance), the reaction was carried out at 80 ° C for 3 hours. 0.02 parts of tin octylate was added to this reaction solution, and ME was used as a diluting solvent.
40 parts of a mixed solvent of 1: 1: 1 (weight ratio) of K, DEK and DMF was added and reacted at 80 ° C. for 1 hour to obtain a prepolymer solution. Separately, in 30.6 parts of a mixed solvent of 1: 1: 1 (weight ratio) of MEK, DEK and DMF, 4,4'-DDS14.
A solution having 9 parts dissolved therein was prepared, and the whole amount of the prepolymer solution was added dropwise to the solution to react at 90 ° C. for 2 hours to obtain an amine adduct solution (solid content 60%). 100 parts of this amine adduct solution and novolac type epoxy resin D
23 parts of EN-438 (Dow Chemical), 3 parts of curing accelerator boron trifluoride benzylamine, and 0.5 parts of silane coupling agent Sila Ace S510 (Chiso) were mixed to prepare a one-component adhesive. Using this adhesive, a composite vibration-damping metal plate was manufactured by the method described in the examples, and the adhesion test, vibration-damping measurement, and heat resistance test were performed.

Example 2 Sebacic acid was used as the dicarboxylic acid component, and the same reaction as in Example 1 was conducted except for the above, and evaluation was carried out.

Example 3 Adipic acid / terephthalic acid = 8 as dicarboxylic acid component
/ 2 (molar ratio) was used, and otherwise the same reaction as in Example 1 was carried out and evaluated.

Examples 4 to 6 The amine adduct solution obtained in Example 1 (solid content 60
%) Was mixed with another type of epoxy resin and a curing accelerator and evaluated in the same manner.

Comparative Examples 1 and 2 The polyester diol of Example 1 has a number average molecular weight of 20.
00 (Comparative Example 1) and 7000 (Comparative Example 2) were produced, and otherwise the same reaction as in Example 1 was carried out and evaluated.

Comparative Examples 3 to 5 Neopentyl glycol (Comparative Example 3), 2,2-diethyl-1,3-propanediol (Comparative Example 4) and 2-n-pentyl-2-n-propyl were used as glycol components. −
1,3-Propanediol (Comparative Example 5) was used, and otherwise the same reaction as in Example 1 was carried out and evaluated.

Comparative Example 6 Adipic acid / terephthalic acid = 6 as dicarboxylic acid component
/ 4 (molar ratio) was used, and otherwise the same reaction as in Example 1 was carried out and evaluated.

Comparative Example 7 4,4'-diaminodiphenylmethane was used as a diamine component, and the same reaction as in Example 1 was carried out for other evaluations.

Regarding the reaction molar ratios and molecular weights of the polyester diols [I to IX] according to the above Examples 1 to 6 and Comparative Examples 1 to 7, the test results of the amine adduct and the adhesive according to [Table 1] [ Table 2].

[0031]

[Table 1]

[0032]

[Table 2]

According to these results, the results obtained by using I to III according to Examples 1 to 6 as the polyester diol are higher than those obtained by using IV to VIII according to Comparative Examples 1 to 6 as the polyester diol. coefficient)
Is excellent in. In Comparative Example 7, since 4,4′-diaminodiphenylmethane was used as the diamine, the storability of one liquid was extremely short.

Claims (7)

[Claims] 1. An isocyanate group-terminated prepolymer (C) obtained by reacting a polyester diol (A) with an aromatic diisocyanate (B) and a diamine (D) at a reaction molar ratio of (D) / (C). The resulting amine adduct (E) at the amino group terminal is reacted so that ≧ 2,
A thermosetting vibration-damping adhesive having excellent heat resistance, which is used as a curing agent for a heat-resistant epoxy resin (F). 2. The polyester diol (A) is 2-n
-Butyl-2-ethyl-1,3-propanediol (abbreviated as DMH) is reacted with a dicarboxylic acid containing 80 mol% or more of an aliphatic dicarboxylic acid, and the thermosetting type according to claim 1. Damping adhesive. 3. The thermosetting vibration-damping adhesive according to claim 1, wherein the amine adduct (E) has a number average molecular weight of 4,000 to 7,000. 4. The thermosetting vibration-damping adhesive according to claim 1, wherein a diamine having a low reaction rate is used as the diamine (D). 5. A prepolymer (C) having an isocyanate group terminal obtained by reacting a polyester diol (A) with an aromatic diisocyanate (B) and a diamine (D) at a reaction molar ratio of (D) / (C). A fast-setting heat that can be used as one liquid by using the resulting amine adduct (E) at the amino group, the heat-resistant epoxy resin (F), and the curing accelerator (G) as essential components Curing type vibration damping adhesive. 6. The isocyanate group-terminated prepolymer (C) obtained by reacting a polyester diol (A) with an aromatic diisocyanate (B) and a diamine (D) at a reaction molar ratio of (D) / (C). A thermosetting vibration-damping adhesive having excellent heat resistance, which is obtained by reacting the resulting amine adduct (E) at the amino group end as a curing agent for a heat-resistant epoxy resin (F) A composite plate, which is an intermediate layer of two plate-shaped members and is formed by curing the adhesive, and has a vibration damping performance in a wide temperature range. 7. A prepolymer (C) having an isocyanate group terminal obtained by reacting a polyester diol (A) with an aromatic diisocyanate (B) and a diamine (D) at a reaction molar ratio of (D) / (C). A fast-setting heat that can be used as one liquid by using the resulting amine adduct (E) at the amino group, the heat-resistant epoxy resin (F), and the curing accelerator (G) as essential components A composite plate having a vibration-damping performance in a wide temperature range, which is obtained by hardening the adhesive by using a curable vibration-damping adhesive as an intermediate layer between two plate-shaped members.