JP2577956B2 - Damping material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration damping material.

[Prior art] As a vibration damping material, there are various rubber-like substances, thermoplastic resins and the like to which a filler such as mica, carbon black, calcium carbonate, etc. is added, but the cost is high and the weight is heavy. Have a point. Also, measures have been taken to add the above filler to the polyurethane foam to increase the density and improve the sound insulation performance, but even in this case, the cost increases and the physical properties decrease, which is not satisfactory. I couldn't do it. For this reason, for example, a viscoelastic foam having a large viscous property, such as a foam obtained by post-treating a polyurethane foam, adding asphalt to a raw material of a foam impregnated with asphalt or a polyurethane foam, and integrally foaming is used. there were.

[Problems to be Solved by the Invention] As described above, asphalt-based foams are very inefficient in terms of workability such as contamination of processing equipment by asphalt during hot compression molding, and furthermore, cost is reduced. It has the disadvantage of being expensive. Further, the post-treated asphalt foam has uneven impregnation, and it is difficult to obtain a uniform quality. Also, while it is desirable that the soundproofing material used for vehicles and the like be lightweight, the above-mentioned asphalt foam and various rubbers and resins to which a filler is added have a problem that the density is large and heavy.

[Means for Solving the Problems] The present inventors have intensively studied a vibration damping material having good working efficiency and light weight, and as a result, have reached the present invention. That is, the present invention comprises a polyol (A) having a hydroxyl value of 80 to 2,000, a prepolymer (1) having an NCO% of 5 to 15%, and a prepolymer (2) having an NCO% of 25% or more, and having an average NCO% of 7 to 20. % Of the polyisocyanate (B) in the presence of a catalyst, a thixotropic agent and, if necessary, an additive. Vibration damping material, consisting of Poleol (A) having a hydroxyl value of 80 to 2000, prepolymer (1) having an NCO% of 5 to 15%, and organic polyisocyanate (3) having an NCO% of 30% or more, and having an average NCO% of 7 2. A vibration damping material comprising a polyurethane foam obtained by reacting a polyisocyanate (C) of about 20% with a catalyst, a thixotropic agent and, if necessary, an additive.
4. A vibration damping material for an automobile, comprising the vibration damping material according to any one of 3.

In the present invention, as the polyol (A), those usually used for polyurethane are used. For example, polyether polyol, polyester polyol, polybutadiene glycol, castor oil, polycarbonate diol and the like can be mentioned.

As polyether polyols, polyhydric alcohols,
Compounds having a structure in which an alkylene oxide is added to an active hydrogen atom-containing polyfunctional compound such as a polyhydric phenol, an amine, or a polycarboxylic acid are exemplified.

Examples of the polyhydric alcohol include ethylene glycol,
Dihydric alcohols such as propylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol and trivalent or higher polyvalents such as glycerin, trimethylolpropane, pentaerythritol, sorbitol, and sucrose Alcohol, etc .;
Examples of the polyhydric phenols include polyphenols such as pyrogallol and hydroquinone, as well as bisphenols such as bisphenol A; condensates of phenol and formaldehyde (novolak) such as polyphenols described in US Pat. No. 3,265,461.

Examples of amines include ammonia; mono-, di-, and triethanolamine, isopropanolamine,
Alkanolamines such as aminoethylethanolamine; C1-C20 alkylamines; C2-C6 alkylenediamine such as ethylenediamine, propylenediamine,
Aliphatic amines such as hexamethylenediamine, polyalkylenepolyamines such as diethylenetriamine and triethylenetetramine; aniline, phenylenediamine, diaminotoluene, xylylenediamine, methylenedianiline, diphenyletherdiamine and other aromatic amines; isophoronediamine, cyclohexene Alicyclic amines such as silenediamine; aminoethylpiperazine and other heterocyclic amines described in JP-B-55-21044;

Examples of the polycarboxylic acid include aliphatic polycarboxylic acids such as succinic acid, adipic acid, sebacic acid, maleic acid, and dimer acid, and aromatic polycarboxylic acids such as phthalic acid, terephthalic acid, and trimellitic acid. The above-mentioned active hydrogen atom-containing polyfunctional compounds may be used in combination of two or more. Preferred among these active hydrogen atom-containing polyfunctional compounds are polyhydric alcohols and amines.

Examples of the alkylene oxide to be added to the active hydrogen atom-containing polyfunctional compound include ethylene oxide (abbreviated as EO), propylene oxide (abbreviated as PO), butylene oxide, and tetrahydrofuran. Alkylene oxide may be used alone or in combination of two or more,
In the latter case, block addition or random addition may be used.
Preferred of these alkylene oxides are P
O, EO and tetrahydrofuran.

Examples of the polyester polyol include a condensed polyester polyol and a lactone (such as ε-caprolactone) obtained by reacting a low molecular polyol (the dihydric alcohol, trimethylolpropane, glycerin, etc.) with a dicarboxylic acid (the polycarboxylic acid, etc.). And the like. Polyester polyols obtained by ring-opening polymerization of (a).

As the polycarbonate polyol, the above described 2 to 2
Examples thereof include those obtained from a trihydric alcohol and a carbonic acid diester (dimethyl carbonate, diethyl carbonate, etc.).

JP-A-55-98220 as polybutadiene glycol
No., pages 449-450 of the Japan Rubber Association Vol. 45 (1972),
Examples include those described in Searants (Damsys, Rainhold, 1967).

Of these, preferred are di- to tri-valent polyether polyols and / or polyester polyols and / or polycarbonate polyols. These may be used as a mixture if necessary. The hydroxyl value is usually
It is 80 to 2000, preferably 80 to 1500. When the hydroxyl value is out of this range, the vibration damping property is poor.

The polyisocyanate (B) used in claim 1 or 2 is a prepolymer (1) having an NCO% of 5 to 15% and N
It is composed of a prepolymer (2) having a CO% of 25% or more.
Polyisocyanate (C) used in claim 3
Is prepolymer (1) with 5-15% NCO% and 30% NCO%
It comprises the above organic polyisocyanate. The prepolymers (1) and (2) can be obtained by reacting a polyol with an organic polyisocyanate by a known method under a condition where the organic polyisocyanate is in a stoichiometric excess.

The average NCO% of the polyisocyanate is usually 7 to 20%, preferably 10 to 15%. If it is less than 7% or more than 20%, the vibration damping property is poor.

As the polyol used for the production of the prepolymer, those similar to the polyol (A) can be used. Of these, preferred are di- to tri-valent polyether polyols and / or polyester polyols and / or polycarbonate polyols. These may be used as a mixture if necessary. Particularly preferred is a divalent polyether polyol. The hydroxyl value is usually 28 to 180, preferably 28
~ 150.

Outside this range, the viscosity of the prepolymer becomes high, and there is no remarkable effect on the damping properties of the damping material.

The polyol used for producing the prepolymer (1) and the polyol used for producing the prepolymer (2) may be the same or different. As the organic polyisocyanate used in the production of the prepolymers (1) and (2), and the organic polyisocyanate used in the third aspect, those which can be generally used for polyurethane are used. For example, an aromatic polyisocyanate having 6 to 20 carbon atoms (excluding carbon in the NCO group) [2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4'- and / or 4,4′-diphenylmethane diisocyanate (MDI), crude MDI [condensation product of crude diaminodiphenylmethane @ formaldehyde and aromatic amine (aniline) or a mixture thereof: triaminodiphenylmethane and a small amount (eg, 5 to 20% by weight) of three or more functional groups Phosgenides of mixtures with polyamines of the following:
Polyaryl polyisocyanate (PAPI)], etc.]: aliphatic polyisocyanate having 2 to 18 carbon atoms [hexamethylene diisocyanate, lysine diisocyanate, etc.]:
Alicyclic polyisocyanates having 4 to 15 carbon atoms (such as isophorone diisocyanate and dicyclohexylmethylene diisocyanate): araliphatic polyisocyanates having 8 to 15 carbon atoms (such as xylylene diisocyanate): and mixtures of two or more of these. Of these, preferred are 2,4- and 2,6-TDI, and mixtures of these isomers, 2,4'- and 4,4'-MDI, and mixtures of these isomers, crude MDI, and a mixture of TDI and MDI, having an NCO% of usually 30 to 55%, preferably 30 to 50%
%.

Known catalysts can be used for the present invention.
Specifically, metal salts of carboxylic acids such as sodium acetate, lead octylate, zinc octylate, cobalt naphthenate and the like: alkoxy and phenoxides of alkali and alkaline earth metals, such as sodium methoxide,
Sodium phenoxide: tertiary amines such as triethylamine, triethylenediamine, N-methylmorpholine, dimethylaminomethylphenol, pyridine and the like: quaternary ammonium bases such as tetraethylammonium hydroxy and the like: imidazoles such as imidazole and 2-ethyl-4- Methylimidazole and the like: organometallic compounds such as tin and antimony, for example, tetraphenyltin, tributylantimony oxide and the like can be mentioned. Of these, preferred are organometallic compounds such as tin and antimony and / or
Or a tertiary amine. The amount of the catalyst used is 0.1 to 5 parts, preferably 0.3 to 3 parts, per 100 parts of the total amount of the polyol. Outside this range, an appropriate curing time cannot be obtained.

As the thixotropic agent used in the present invention, surface-treated inorganic fillers and synthetic waxes usually used for urethane are used. Examples of these include colloidal hydrophobic silica, surface-treated precipitated calcium carbonate and hydrogenated castor oil. Preference is given to surface-treated precipitated calcium carbonate and / or hydrogenated castor oil.

The thixotropic agent may be added to either the polyol (A) or the polyisocyanate (B), or may be added to both. The addition amount is usually 4 to 60%, preferably 6 to 50% based on the total amount of the polyol (A) and the polyisocyanate (B). If it is less than 4%, the thixotropy is insufficient, and if it is more than 60%, the workability is poor.

Additives used as necessary in the present invention include foam stabilizers, foaming agents, auxiliaries and the like.

As the foam stabilizer, those for urethane foam are usually used. For example, L-540 (Nihon Unicar Co., Ltd.)
), SH-193, SH-190, SRX-294A, SRX-274C (manufactured by Toray Silicone Co., Ltd.). The amount used is not particularly limited, but is usually 0.5 to 5 parts with respect to 100 parts of the polyol.

Blowing agents include water and / or halogenated hydrocarbons (Freon, methylene chloride, etc.). The amount used is not particularly limited, but is usually 15 per 100 parts of polyol.
Part or less.

The specific gravity of the polyurethane (foam) is usually 0.02 or more, preferably 0.04 or more.

Auxiliaries include fillers and colorants. The above-mentioned additives may be added to either the polyol (A) or the polyisocyanate (B), or may be added to both (however, water is added to the polyol (A)).

The NCO index at the time of producing the polyurethane of the present invention is not particularly limited, but is usually 90 to 110.

The vibration damping material of the present invention can be used as a vibration damping material for a transportation vehicle such as a car, a train, an aircraft, etc., a factory, a machine, a house, and the like, which is particularly subject to vibration, and is particularly effective as a vibration damping material for an automobile. Specific examples include vertical parts such as doors and instrument panels of automobile parts, complicated parts around an engine, and vibration damping materials such as car molded foam backing carpets. Further, since the vibration damping material can be easily manufactured by a conventional foaming device or spray device, the productivity is improved.

EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

The composition of the raw materials used in the examples and comparative examples will be described.

Polyol 1 ethylene glycol.

Polyol 2: PO is added to glycerin to give a hydroxyl value of 420
Stuff.

Polyol 3: PO value added to glycerin, hydroxyl value 673
Stuff.

Polyol 4: PO added to glycerin to give a hydroxyl value of 168
Stuff.

Catalyst: 17% dioctyl phthalate solution of lead octylate.

Thixotropic agent (1): calcite-type precipitated calcium carbonate (Gerton 50 (manufactured by Shiraishi Industry Co., Ltd.)) thixotropic agent (2): hydrogenated castor oil (Disparon 411)
0) (Kusumoto Kasei Co., Ltd.) Prepolymer (1): A product in which PO is added to propylene glycol, and a polyether polyol having a hydroxyl value of 123 is reacted with TDI-80 to obtain an NCO% of 7.2%.

Prepolymer (2): A product in which PO is added to propylene glycol, and a polyether polyol having a hydroxyl value of 75 is reacted with MDI to obtain an NCO% of 26%.

Organic polyisocyanate (3): Millionate MR (Nippon Polyurethane Industry Co., Ltd., NCO% 30%) Examples 1 to 6, Comparative Examples 1, 2 Manufactures vibration damping materials based on the formulations shown in Tables 1 and 2. did.
The obtained damping material was measured for density, coating amount and damping property [loss coefficient at 20 ° C and 40 ° C by vibrating lead method]. The results are shown in Tables 1 and 2. As a measurement sample of vibration damping properties, a 200 × 20 × 0.8 mm ³ steel sheet coated with polyurethane was used.

As is clear from the measurement results, 20 ° C. of Examples 1 to 6 and
The loss coefficient at 40 ° C. is higher than that of the comparative example, which indicates that the vibration damping property is excellent.

Example 7 A spray device (APW-5000 manufactured by Asahi Okuma Sangyo Co., Ltd.) was used to spray the composition of Example 2 onto a dash insulator board, and the damping property was examined. The damping properties were good.

[Effects of the Invention] As is clear from the above results, the damping material comprising the polyol and the organic polyisocyanate specified in the present invention has excellent damping properties. Moreover, since asphalt is not used, the processing apparatus is not contaminated by asphalt during processing such as hot compression molding, and the working efficiency is not reduced. Further, since no filler is used, it is light and particularly preferable as a damping material for automobiles.

Furthermore, the vibration damping material of the present invention is such that polyurethane is dripped by the effect of the thixotropic agent even when vertical parts such as door panels and dash silencers are manufactured by a conventional apparatus using a one-shot method or a spray method. There is also a feature that there is no.

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Claims (4)

(57) [Claims] 1. A polyol (A) having a hydroxyl value of 80 to 2,000 and NC
A polyisocyanate (B) comprising a prepolymer (1) having an O% of 5 to 15% and a prepolymer (2) having an NCO% of 25% or more and having an average NCO% of 7 to 20% as a catalyst and a thixotropic agent; A vibration damping material comprising a polyurethane which is reacted in the presence of an additive, if necessary. 2. The vibration damping material according to claim 1, wherein the polyurethane is a polyurethane foam. 3. A polyol (A) having a hydroxyl value of 80 to 2,000 and NC.
Prepolymer (1) with O% of 5 to 15% and organic polyisocyanate (3) with NCO% of 30% or more, average NCO%
A polyisocyanate (C) having a content of 7 to 20% in the presence of a catalyst, a thixotropic agent and, if necessary, an additive, comprising a polyurethane foam. 4. A vibration damping material for an automobile, comprising the vibration damping material according to claim 1.