JPH0639516B2 - Manufacturing method of viscoelastic resin for damping material - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a viscoelastic resin for a vibration damping material, and more specifically to a vibration damping member for a structural member of various structures such as machines, buildings and vehicles, or a damping structure for a covering structure used as a part thereof. The present invention relates to a method for producing a viscoelastic resin for a vibration damping material used as an intermediate layer in the material.

[Conventional technology]

In recent years, the problems of noise and vibration have become a social problem as pollution due to the development of transportation facilities and the approach to houses and factories.In addition, noise and vibration are regulated in the workplace to improve the working environment. Tend to do. Corresponding to such a tendency, the vibration damping performance of the metal material that is the noise source or the vibration source, that is, the vibration energy of the member that generates noise is absorbed and converted into heat energy, and the vibration velocity or vibration amplitude It has been demanded to add a function of attenuating the light source to reduce the acoustic emission and further improve the function.

Based on such a demand, as one of the vibration damping materials exhibiting such performance, a composite vibration damping material having a multilayer structure in which an intermediate layer having viscoelasticity is sandwiched between metal layers has been conventionally proposed. There is. And, this composite type vibration damping material is used for automobile oil pans, engine covers, hopper chute parts, transport equipment stoppers, home appliances, and other vibration reduction members for metal working machines and structural members for precision machinery where vibration prevention is desired. Etc. have been examined and adopted.

Generally, the damping performance of such a composite damping material depends on the performance of the viscoelastic intermediate layer constituting the intermediate layer.
This damping performance is expressed as a loss factor (a quantity related to mechanical hysteresis loss due to vibration, which is a measure of conversion of vibration energy from the outside into heat energy due to internal friction), and this damping performance has a peak characteristic at a certain temperature. Indicates
It is known that it is most effective to use in the vicinity of this peak characteristic temperature.

Conventionally, as a viscoelastic composition constituting the viscoelastic intermediate layer of such a composite type vibration damping material, polyester alone (JP-A-50-143880) or polyester with a plasticizer added (JP-A-SHO) No. 51-93770), a single polyurethane foam (JP-A-51-919).
No. 81), polyamide alone (JP-A-56-1591).
No. 60), ethylene-vinyl acetate copolymer alone (JP-A-57-34949), polyvinyl butyral or a composition of polyvinyl butyral and polyvinyl acetate mixed with a plasticizer and a tackifier (special Kosho 5
No. 5-27975), a copolymer of an isocyanate prepolymer and a vinyl monomer (Japanese Examined Patent Publication (Kokoku) No. 52-26554).
Japanese Patent Publication No. 39-12451, Japanese Patent Publication No. 45-34703, and the like.

[Problems to be solved by the invention]

By the way, the composite damping material is required to have a high loss coefficient and a high adhesive strength between the viscoelastic intermediate layer made of the viscoelastic composition and the metal layer. However, there is a problem in any of the performances in the composite vibration damping material produced by the conventional viscoelastic composition,
I was not completely satisfied. In particular, in order to exhibit high vibration damping performance at around room temperature, it is necessary to set the glass transition temperature to room temperature or lower, and in conventional known resins, when the glass transition temperature is lowered, the adhesive strength is greatly reduced, Therefore, it cannot be used in applications requiring high adhesiveness.

[Means for solving problems]

In view of these problems, the inventors of the present invention have arrived at the present invention as a result of earnest studies on an intermediate layer for a vibration damping material, which has a high vibration damping performance especially near room temperature and has a high adhesive force.

That is, in the present invention, 60 mol% or more of the dicarboxylic acid component is an aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid having 4 to 20 carbon atoms, and 50 mol% or more of the glycol component has an alkyl group in the side chain. Polyester diol (A) having a molecular weight of 600 to 6000, which is an aliphatic glycol having 3 to 6 carbon atoms and / or a derivative thereof, and a chain extender having a molecular weight of 400 or less.
(B), the diisocyanate compound (C) and (A), (B) and
In a solvent that dissolves (C), a weight ratio of (A) :( B) :( C) = 10
The ratio of 0: 1 to 20:10 to 100, and the isocyanate group of (C) 0. 1 to 1 equivalent of the active hydrogen group of (A) + (B).
Number average molecular weight 8 to be reacted at a ratio of 85 to 1.15 equivalents
000 to 100,000, glass transition temperature -50 ° C to 30
It is a method for producing a viscoelastic resin for composite vibration damping materials having a characteristic of ℃.

The polyester diol (A) used in the polyurethane resin of the present invention has 60 mol% or more of the dicarboxylic acid component composed of an aliphatic dicarboxylic acid having 4 to 20 carbon atoms and / or an alicyclic dicarboxylic acid, but having 4 to 20 carbon atoms. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, decamethylenedicarboxylic acid, dodecanedicarboxylic acid, tetradecanedicarboxylic acid, and the like, and alicyclic dicarboxylic acids include 1,4- Examples thereof include cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid and 1,2-cyclohexanedicarboxylic acid. Examples of the dicarboxylic acid component that can be used in the range of less than 40 mol% include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, 1,5-naphthalenedicarboxylic acid, and 2,6-naphthalenedicarboxylic acid, or dimer acid. Examples thereof include long-chain aliphatic dicarboxylic acids, and hydroxybenzoic acids such as p-oxybenzoic acid and p- (2-hydroxyethoxy) benzoic acid.

Further, the glycol component of the polyester diol (A) needs to contain 50 mol% or more of the aliphatic glycol having 3 to 6 carbon atoms and / or its derivative having an alkyl group in the side chain in the total glycol, but having 3 carbon atoms. Examples of the aliphatic glycol having an alkyl group in the side chain of ~ 6 include 1,2-
Propylene glycol, 1,3-butanediol, neopentyl glycol, 3-methylpentanediol, 2
-Methyl-2-ethyl-1,3-propanediol and the like can be mentioned, and as the derivative compound, neopentyl glycol hydroxypivalate can be mentioned. As glycols that can be used in combination with these side chain alkyl group-containing glycols, ethylene glycol,
1,3-propanediol, 1,4-butanediol,
Aliphatic glycols such as 1,6-hexanediol, 1,5-pentanediol and 1,9-nonanediol,
An alicyclic glycol such as 1,4-cyclohexanedimethanol, an aromatic ring-containing glycol such as an alkylene oxide adduct of bisphenol A, or a cyclic ester compound such as ε-caprolactone or 3-methylvalerolactone can also be used.

The polyester diol (A) in the present invention is preferably bifunctional, but as long as the characteristics are not impaired, trifunctional or higher polycarboxylic acid or polyol is used in an amount of 5 mol per total dicarboxylic acid component or total diol component. %
It is also possible to use within.

As the chain extender (B) having a molecular weight of 400 or less used in the polyurethane resin of the present invention, ethylene glycol, 1,
2-propanediol, 1,4-butanediol, 1,
Aliphatic glycols such as 6-hexanediol and neopentyl glycol, alicyclic glycols such as 1,4-cyclohexanedimethanol, alkylene oxide adducts of bisphenol A, aromatic ring-containing glycols such as xylylene glycol, ethylenediamine, tetramethylene. Diamine, hexamethylene diamine, 2,2-dimethyl-
Aliphatic diamines such as 1,3-propanediamine and 2-methyl-4,4-dimethyl-1,6-hexanediamine,
Hydroxyl group-containing amino compounds such as ethanolamine and N-methylmonoethanolamine, p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 4,4′-diaminodiphenylmethane, 3,3 ′
-Diaminodiphenylmethane, 4,4'-diamino-
3,3 ', 5,5'-tetramethyldiphenylmethane,
Examples thereof include aromatic diamines such as 4,4'-diaminodiphenyl ether and 4,4'-diaminodiphenyl sulfone.

Next, as the diisocyanate compound (C), 2,4-
Tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenylene diisocyanate, diphenylmethane diisocyanate, m-phenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, 3,3′-dimethoxy-4,
4'-biphenylene diisocyanate, 2,4-naphthalene diisocyanate, 3,3'-dimethyl-4,4 '
-Biphenylene diisocyanate, 4,4'-diphenylene diisocyanate, 4,4'-diisocyanate-
Diphenyl ether, 1,5-naphthalene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, 1,3-diisocyanate methylcyclohexane, 1,4-diisocyanate methylcyclohexane, 4,4′-diisocyanate dicyclohexane, 4 , 4'-diisocyanate dicyclohexylmethane, isophorone diisocyanate and the like,
If necessary, a small amount of 2,4,4'-triisocyanate-diphenyl, benzenetriisocyanate or the like can be used.

The polyester diol (A) used in the polyurethane resin of the present invention comprises 60 mol% or more, preferably 70 mol% or more of dicarboxylic acid components derived from an aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid having 4 to 20 carbon atoms. Consists of
If it is less than 60 mol%, excellent vibration damping performance cannot be exhibited near room temperature. As for the glycol component of the polyester diol (A), a glycol having 3 to 6 carbon atoms and / or a derivative thereof having an alkyl group in the side chain is required to be 50 mol% or more, preferably 70 mol% or more in the total glycol.
If it is less than mol%, it is difficult to exhibit high vibration damping performance.

The chain extender having a molecular weight of 400 or less used in the polyurethane resin of the present invention is used in an amount of 1 to 20 parts, preferably 1.5 to 12 parts, relative to 100 parts of the polyester polyol (A). On the contrary, when it exceeds 20 parts, the vibration damping performance at around room temperature deteriorates, and the depth of the resin becomes poor and the performance such as drawability becomes poor.

The polyurethane resin of the present invention has (A) :( B) :( C) = 100:
1 to 20:10 to 100 (weight ratio) 0.85 to isocyanate groups of (C) to 1 equivalent of active hydrogen groups of (A) + (B)
It is obtained by reacting at a ratio of 1.15 equivalents, preferably 0.90 to 1.10 equivalents, but even if the isocyanate compound is less than 10 parts or less than 0.85 equivalents, conversely exceeds 100 parts, or 1.15 equivalents. Even if the equivalent weight is exceeded, the molecular weight of the polyurethane resin will be low and high adhesive strength cannot be expected.

Two or more kinds of the polyester diol (A) used in the polyurethane resin of the present invention can be used if necessary, and the polyester diol (A) of the present invention can be used in an amount of 100 parts by weight of the present invention as long as the performance is not impaired. Polyester diol or polyether diol not included in
30 parts or less of polycarbonate diol, preferably 2 parts
It is also possible to use within a range of 0 part or less.

The number average molecular weight of the polyurethane resin of the present invention is 8000 to
100,000 preferably 20,000 to 60,000, and glass transition temperature is -50 ° C to 30 ° C, preferably-
It is 40 ° C to 10 ° C.

If the number average molecular weight is less than 8,000, high adhesive strength cannot be expected, and if it exceeds 100,000, the viscosity becomes too high, and the coating workability becomes difficult, resulting in impracticality. If the glass transition temperature is lower than -50 ° C, the vibration damping performance at room temperature or higher is significantly lowered, and the cohesive force of the resin is lowered, so that it becomes difficult to obtain a high adhesive force. On the other hand, if the temperature exceeds 30 ° C, the vibration damping performance at room temperature or lower is significantly reduced.

The polyurethane resin of the present invention has excellent vibration damping properties and adhesive properties when used alone, but if necessary, other compatible resins such as polyester resin, epoxy resin, petroleum resin and acrylic copolymer are used. It can be used as a mixture with a combination or the like, and if necessary, a compound which reacts with a polyurethane resin such as a polyisocyanate compound can also be used as a mixture.

When the resin of the present invention is used as an intermediate layer of a vibration damping material, it goes without saying that the above resin can be used as it is, but in addition to this, various kinds of glass fiber, polyester fiber, carbon fiber and the like for the purpose of increasing the resin strength. Fibers, various particles of calcium carbonate, magnesium carbonate, etc., or various metal powders and metal fibers such as stainless powder, aluminum powder, etc. for the purpose of imparting point contact weldability, or conductive particles such as carbon black and graphite, In addition, it goes without saying that one or more kinds of various coupling agents may be appropriately selected and used for the purpose of improving the adhesiveness between the mixed inorganic substance and the resin, and various leveling agents for the purpose of improving the coating property.

The viscoelastic resin of the present invention having such a structure exhibits a marked effect as compared with the conventional viscoelastic substance for vibration damping materials. That is, it is difficult to satisfy both the good vibration damping performance and the good adhesive force with the conventional viscoelastic material for vibration damping materials, but it is possible to suppress the vibration by using the viscoelastic resin for vibration damping material of the present invention. It is possible to improve vibration performance and obtain high adhesive strength.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to Examples. In Examples, "parts" means "parts by weight".

In addition, the measurement of the vibration absorption performance in Table 3 is shown by the loss coefficient η, and the 0.8 mm thick bonder-treated steel plate (SPCE
This is a relationship between the temperature and the loss coefficient at a vibration frequency of 500 Hz for a vibration damping steel plate in which a 0.05 mm thick viscoelastic resin layer is sandwiched between two sheets.

As shown in the comparative example in Table 3, polyester diol
When the molecular weight of (A) is less than 600, the isocyanate compound (C) is more than 100 parts, or the diisocyanate compound (C) is added to 1 equivalent of active hydrogen groups of the polyester diol (A) and the chain extender (B). If the isocyanate group of 1) is more than 1.15 equivalents, high vibration damping performance cannot be obtained.

When the molecular weight of the polyester diol (A) is more than 6000, the isocyanate compound (C) is less than 10 parts, or the diisocyanate compound (C) is added to 1 equivalent of the active hydrogen group of the polyester diol (A) and the chain extender (B). When the isocyanate group of 1) is less than 0.85 equivalent, high shear adhesive strength cannot be obtained.

Example of production of polyester diol Adipic acid 292 parts, neopentyl glycol 25 in a reactor equipped with a thermometer, a stirrer, and a condenser for distillation.
0 parts, 70 parts of 3-methylpentanediol and 0.14 parts of tetrabutyl titanate were charged, the esterification reaction was carried out at 200 to 230 ° C. for 3 hours, and then the reaction system was depressurized to 20 mmHg over 30 minutes. . Care should be taken not to cause clogging inside the condenser due to the distilling of neopentyl glycol, and further 1 to 20 mmHg, 250 ° C,
Polycondensation reaction is carried out for 45 minutes, and polyester diol (a
-1) was obtained.

The polyester diol (a-1) has a molecular weight of 2500 hydroxyl value of 44 (KOHmg / g), and the NMR analysis shows that the dicarboxylic acid component adipic acid is 100 mol%, the glycol component neobenthyl glycol is 77 mol%, and 3 -Methylpentanediol was confirmed to be 23 mol%.

Polyester diols (a-2) to (a-11) shown in Table 1 were obtained by the same production method.

Production Example of Polyurethane Resin A reactor equipped with a thermometer, a stirrer and a reflux condenser was charged with 50 parts of toluene and 50 parts of methyl ethyl ketone, and then 100 parts of polyester diol (a-1) shown in Table 1 was added and dissolved. To do. Next, 16.4 parts of isophorone diisocyanate and 0.02 part of dibutyltin dilaurate were added and reacted at 70 to 80 ° C. for 3 hours, and then 4,4′-
7 parts of diaminodiphenylmethane was added, and the mixture was further reacted at 70 to 80 ° C. for 4 hours. During this period, 94 parts of toluene and 94 parts of methyl ethyl ketone were added in accordance with the increase in viscosity to make the final solid content concentration 30% by weight.

The resulting polyurethane resin (D-1) has a number average molecular weight of 3
It had a glass transition temperature of 8000 and a glass transition temperature of -25 ° C.

By the same method, the polyurethane resin (D
-2) to (D-15) were obtained.

[Effects of the Invention] As is clear from the above examples, the viscoelastic resin of the present invention exhibits high vibration damping performance and excellent adhesiveness by being sandwiched between two metal plates, and is extremely Since it enables excellent press molding, it is extremely useful as a viscoelastic resin for composite vibration damping materials.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobuo Kadowaki 5-10-1 Fuchinobe, Sagamihara City, Kanagawa Pref., Second Research Laboratory, Nippon Steel Corporation (72) Takeshi Yatsuka, Katata, Otsu City, Shiga Prefecture No. 1-1 Toyobo Co., Ltd. Research Institute (72) Inventor Yu Mizumura 2-1-1 Katata, Otsu City, Shiga Prefecture Toyobo Co., Ltd. Research Institute (56) Reference JP 61-14221 (JP, A) JP 60-92317 (JP, A) JP 54-127499 (JP, A) JP 50-143880 (JP, A) JP 51-93770 (JP, A) JP 51 -91981 (JP, A) JP 56-159160 (JP, A) JP 52-26554 (JP, B2)

Claims (1)

[Claims] 1. 60 mol% or more of a dicarboxylic acid component is an aliphatic dicarboxylic acid and / or alicyclic dicarboxylic acid having 4 to 20 carbon atoms, and 50 mol% or more of a glycol component has an alkyl group in a side chain. Molecular tatami mat 600, which is an aliphatic glycol having 3 to 6 carbon atoms and / or a derivative thereof,
A polyester diol (A) of 6000, a chain extender (B) having a molecular weight of 400 or less, and a diisocyanate compound (C)
In a solvent that dissolves (A), (B) and (C) in a weight ratio (A):
(B): (C) = 100: 1 to 20:10 to 100, and (C) isocyanate group 0.85 to 1.15 per 1 equivalent of active hydrogen group of (A) + (B). A method for producing a viscoelastic resin for a composite vibration damping material, which has a number average molecular weight of 8000 to 100000 and a glass transition temperature of -50 ° C to 30 ° C, which are reacted in an equivalent ratio.