JP3395296B2 - Vibration energy absorber - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is used in various fields such as transportation equipment, precision electronic equipment, and acoustic equipment for the purpose of improving the reaction speed and measurement accuracy and the sound quality by controlling vibration. The present invention relates to a polyvinyl chloride resin composition having excellent vibration energy absorption performance.

[0002]

2. Description of the Related Art Conventionally, butyl rubber has been most often used as a vibration energy absorbing material. Further, recently, polynorbornene and special urethane elastomers have been found to have higher performance and have been attracting attention.

The primary evaluation of these vibration energy absorbing materials is the storage elastic modulus (E) obtained by viscoelasticity measurement of the material.
′) And loss coefficient (tan δ = loss elastic modulus (E ″) / storage elastic modulus (E ′)).

For designing a vibration energy absorbing material, the larger the loss coefficient is, and the storage elastic modulus has an optimum value depending on the form used.

These two factors are usually highly temperature dependent. That is, the storage elastic modulus gradually decreases as the temperature rises, and usually sharply decreases from the temperature range exceeding the glass transition point. Further, the loss coefficient shows the highest value in the temperature range exceeding the glass transition point, but generally tends to decrease in the temperature range before and after that.

Therefore, conventionally, the standard required for such a vibration energy absorbing material has been to have a high loss coefficient in the temperature range in which the material is used.

On the other hand, the storage elastic modulus can be adjusted to an optimum value because the value can be adjusted in a considerable range by adding an inorganic or metallic filler, a softening agent, or rubber. . Therefore, butyl rubber, polynorbornene, special urethane elastomer, etc. have maximum loss factors of tan δ = 1.4, 2.
It shows an excellent value of 81.3. However, these materials were difficult to process and form, and their use range was limited.

Polyvinyl chloride resin has a long history as one of the five general-purpose resins, and most molding processing methods have been established as well as economical efficiency. In addition, it has advantages such as being an amorphous resin and being easily compounded with an inorganic / metal filler or a softening agent.

The loss factor of polyvinyl chloride alone has a peak value of about 1.1 at around 90 ° C. However, a typical plasticizer, di-2-ethylhexyl phthalate (hereinafter abbreviated as DOP), is added to 1 part by weight per 100 parts by weight of the resin.
When 100 parts by weight is added, the peak temperature of the loss factor becomes about 5 ° C., and the peak value also decreases to about 0.7. It was understood that this phenomenon should be understood if heterogeneous molecules were mixed into the polyvinyl chloride single molecular chain, and as a result, the relaxation time distribution was broadened. However, as a result of our recent studies,
It has been found that when a very limited number of plasticizers and oligomers are added to polyvinyl chloride, the peak temperature of the loss coefficient decreases but the peak value rises to about 2.0.
However, since the polyvinyl chloride-based resin, which is a thermoplastic resin, has extremely poor compression set as compared with rubber or the like, its use is limited even if it has easy moldability.

In recent years, there has been an increasing demand for improvement in molding processability such as profile extrusion molding and precision injection molding, and further for rubber-like properties such as compression set and creep resistance.
Materials having a low compression set and excellent moldability are desired.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a vibration energy absorbing material which is excellent in compression set while taking advantage of the excellent moldability of polyvinyl chloride resin.

[0012]

SUMMARY OF THE INVENTION In view of the present situation as described above, the inventors of the present invention have made extensive studies, and as a result, have completed the present invention. That is, the present invention is based on 100 parts by weight of polyvinyl chloride resin and triisocyanate and polymer.
50-300 parts by weight of a polyurethane (a) having a crosslinked structure composed of a polyol and a plasticizer (b) 20-2
In the vibration energy absorber containing 100 parts by weight, the acid component of the polymer polyol contained in the polyurethane (a) is phthalic acid / aliphatic dicarboxylic acid = 10/0.
It is a vibration energy absorber made of polyurethane in the range of 1/9 (molar ratio). Further, in the above vibration energy absorbing material, the polyurethane (a) has an isocyanate index (number of isocyanate / number of hydroxyl groups) in the range of 0.4 to 0.7. The details will be described below.

As the polyvinyl chloride resin used in the present invention, a vinyl chloride homopolymer resin, a chlorinated vinyl chloride resin, and one or more monomers of all monomers copolymerizable with a vinyl chloride monomer. Chloride copolymer resin (for example, vinyl acetate-vinyl chloride copolymer, ethylene-vinyl chloride copolymer, etc.) obtained by random copolymerization or block copolymerization with these polymers, and these resins may be used alone or as a mixture of two or more kinds. Is mentioned. The degree of polymerization of the polyvinyl chloride resin is not particularly limited, but is 400 or more 8 from the viewpoint of moldability.
000 or less, preferably 500 or more and 5000 or less, more preferably 800 or more and 4000 or less. Also,
A polyvinyl chloride resin having an arbitrary molecular weight may be mixed with the polyvinyl chloride resin having a polymerization degree in these ranges. The polyurethane (a) used in the present invention is triiso
It is a cross-linkable polyurethane composed of cyanate and polymer polyol. Triisocyanate referred to here is no particular limitation. For example, 2,4- and 2,6-tolylene diisocyanate, m- and p-phenylene diisocyanate, 1-chlorophenylene-2,4-diisocyanate, 1,5-naphthalene diisocyanate, methylenebisphenylene-4,4'-diisocyanate. , M- and p-xylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, isophorone diisocyanate, trimethylhexamethylene diisocyanate trimer, 1,6,1
1-undecane triisocyanate, lysine ester triisocyanate, 4-isocyanate methyl-1,8
Examples include triisocyanates such as octamethyldiisocyanate, and one or more of these are used.

As the polymer polyol which is a material for obtaining the polyurethane (a) used in the present invention, a polyester polyol composed of a dicarboxylic acid and a diol is used. Furthermore, the dicarboxylic acid referred to here is phthalic acid or a mixture of phthalic acid and an aliphatic dicarboxylic acid. Although phthalic acid includes isophthalic acid and terephthalic acid, either phthalic acid may be used in the present invention. Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid and the like. The diol is not particularly limited, and 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,4-butanediol, 1,5-pentanediol, ethylene glycol, propylene glycol, neopentyl glycol, etc. Of aliphatic diols are used.

The vibration energy absorbing material of the present invention is characterized by having a high loss coefficient near room temperature. However, by containing phthalic acid as the polymer polyol, the glass transition temperature (Tg) of the obtained polyurethane (a) can be improved. -20 to
It can be operated at 40 ° C., and by mixing the polyurethane (a) with a polyvinyl chloride resin, it becomes easy to operate the Tg of the vibration energy absorbing material of the present invention near room temperature. On the other hand, when phthalic acid is not used as the dicarboxylic acid, and when a polyurethane is made using only adipic acid as the aliphatic dicarboxylic acid, the Tg of the polyurethane is lowered, and when it is mixed with a polyvinyl chloride resin, the temperature becomes around room temperature. Not only is it difficult to control Tg, but the compatibility with the polyvinyl chloride resin is also reduced, making it difficult to obtain a high loss coefficient. Therefore, in the present invention, it is important that the composition ratio of phthalic acid, which is an acid component of the polymer polyol contained in the polyurethane (a), and aliphatic dicarboxylic acid is 10/0 to 1/9 (molar ratio). ,
A particularly preferable composition ratio is 10/0 to 5/5. If the composition ratio is within the range, phthalic acid or a polymer polyol composed of phthalic acid and an aliphatic dicarboxylic acid may be mixed with a polymer polyol composed of a dicarboxylic acid other than phthalic acid. No problem.

The molecular weight of the polymer polyol used here is preferably 300 or more and 10000 or less, more preferably 500 or more and 4000 or less, in view of handling convenience and physical properties of the resulting polyurethane.

The polyurethane (a) in the present invention obtained by using the above polyfunctional isocyanate compound and polymer polyol has an isocyanate index (the number of isocyanate / the number of hydroxyl groups) of 0.4 to 1 which indicates the reaction ratio of isocyanate and polyol. What was manipulated to 1 is preferably used. When the isocyanate index is less than 0.4, it is difficult for the vibration energy absorbing material of the present invention to exhibit rubber-like properties, and in addition, the molding processability may be significantly reduced. If it exceeds, the excess isocyanate may deteriorate the physical properties of the vibration energy absorbing material.

The isocyanate index is 0.
The polyurethane obtained in the range of 4 to 0.7 suppresses the loss coefficient lowering at a temperature higher than Tg, but even when mixed with a polyvinyl chloride resin, this behavior is preferably used, and further, it is preferably 0. More preferably, a polyurethane having an isocyanate index in the range of 4 to 0.55 is used. This behavior hardly occurs when the isocyanate index exceeds 0.7.

In the present invention, the mixing ratio of the polyvinyl chloride resin and the polyurethane (a) is 50 to 50 parts by weight of the polyurethane (a) with respect to 100 parts by weight of the polyvinyl chloride resin in view of compression set resistance and molding processability. The amount is preferably 300 parts by weight, more preferably 100 to 200 parts by weight. When the polyurethane content is less than 50 parts by weight, the vibration energy absorbing material obtained has a poor compression set and the polyurethane content is 300.
When it exceeds the weight part, the moldability of the vibration energy absorbing material obtained is remarkably deteriorated.

In the present invention, the addition of the plasticizer (b) is important for the purpose of improving moldability. The plasticizer that can be used in the present invention is not particularly limited, but for example, dibutyl phthalate, 2-ethylhexyl phthalate,
Phthalic acid plasticizers such as diisodecyl phthalate, diisooctyl phthalate, butylbenzyl phthalate, dicyclohexyl phthalate, di-2-ethylhexyl adipate,
Aliphatic ester plasticizers such as di-2-ethylhexyl sebacate, pyromellitic acid plasticizers such as trioctyl trimellitate, phosphate ester plasticizers such as tributyl phosphate and tricresyl phosphate, epoxidized soybean oil, etc. Polymeric plasticizers typified by epoxy plasticizers and polyester plasticizers, high molecular weight compounds having a Tg lower than that of polyvinyl chloride resins and having plasticizing ability for polyvinyl chloride resins. It is possible to use one or more of these. In particular, when it is intended to improve the loss coefficient of polyvinyl chloride resin, phthalate ester plasticizers having a cyclic structure in the ester group such as dicyclohexyl phthalate and dimethylcyclohexyl phthalate, tricresyl phosphate, phosphorus It is preferable to use a triaryl phosphate ester plasticizer such as trixylenyl acid.

The plasticizer (b) is added in an amount of 20 to 200 parts by weight per 100 parts by weight of the polyvinyl chloride resin.
It is preferably 30 to 150 parts by weight. If it is less than 20 parts by weight, moldability may be impaired, and if it exceeds 200 parts by weight, bleed-out may occur.

The vibration energy absorbing material of the present invention contains inorganic fillers such as calcium carbonate and talc, which are usually added to polyvinyl chloride resins to the extent that the performance is not extremely reduced, antimony trioxide and boro. Add flame retardants typified by zinc oxide, flaky fillers often used for vibration energy absorbers typified by mica and graphite, and tackifying resins such as petroleum resin and rosin as needed. You can Examples of the method for producing the vibration energy absorbing material of the present invention include a method in which a polyurethane prepared in advance is finely crushed by freeze pulverization or the like, and then blended with a polyvinyl chloride resin, a plasticizer and the like. In this case, a device such as a roll, a Banbury mixer, an extruder or the like is used for blending. Further, the vibration energy absorbing material of the present invention can also be obtained by a method in which polyurethane prepared in advance is formed into a sheet by a roll kneader or the like and then blended with a polyvinyl chloride resin, a plasticizer or the like.

The vibration energy absorbing material according to the present invention can be freely formed and processed by the conventional methods of forming and processing polyvinyl chloride resin such as calendering, extrusion, injection molding and compression molding.

Further, the vibration energy obtained by the present invention
The absorber is a supporting member of equipment such as precision electronic equipment and precision measuring equipment whose accuracy is affected by vibration, a fixing member such as packing and gasket, a laminated member and chassis such as audio equipment, sports equipment. It can be used for low repulsion parts. In addition, it is used for the purpose of suppressing vibration by directly attaching it to a place with high vibration such as automobiles and industrial equipment, and used for the leg part of precision equipment to prevent the propagation of vibration from the floor. It can also be used in combination with other materials such as wood and inorganic materials such as metal materials such as aluminum plates.

[0025]

EXAMPLES The present invention will be described below with reference to examples.
The present invention is not limited to these examples.

Example 1 Polyester polyol obtained by condensation polymerization of 3-methyl-1,5-pentanediol with 50 mol% of terephthalic acid and 50 mol% of adipic acid (Clapol PKA-A)
2, a number average molecular weight of 2000, manufactured by Kuraray Co., Ltd., 86 parts by weight and an isocyanurate modified product of hexamethylene diisocyanate as an isocyanate compound ((polyfunctional isocyanate compound, average number of functional groups 3.6 / molecule) (Coronate HX, 15 parts by weight (manufactured by Nippon Polyurethane Industry Co., Ltd.) (isocyanate index = 0.85), and further dibutyltin dilaurate (DBTDL) 7 as a catalyst.
0 ppm was mixed and left in an oven at 120 ° C. for 2 hours to prepare polyurethane.

After pulverizing this, an ethylene-vinyl chloride copolymer (Leuron E-2 was used with a roll set at 150 ° C.
800, Tosoh Co., Ltd. 100 parts by weight, dimethylcyclohexyl phthalate (Edenol 344, Henkel Hakusui Co., Ltd.) 80 parts by weight, trixylenyl phosphate (TX).
P, manufactured by Daihachi Chemical Industry Co., Ltd., 30 parts by weight, petroleum resin (Petcole LX, manufactured by Tosoh Corporation) 20 parts by weight, as stabilizers barium stearate 2 parts by weight, zinc stearate 1 part by weight, amine 1.5 parts by weight of the scavenger was added to the kneaded mixture and kneaded for 10 minutes to obtain a sheet of the intended vibration energy absorbing material.

Example 2 The same operation as in Example 1 was carried out except that 18 parts by weight of isocyanate compound (isocyanate index = 1.0) was used to obtain a desired vibration energy absorbing material.

Example 3 Polyester polyol (MPD / TPA, obtained by condensation polymerization of 3-methyl-1,5-pentanediol and terephthalic acid by adding 20 parts by weight of the polyester polyol used in Example 1) Number average molecular weight 500,
55.4 parts by weight of Kuraray Co., Ltd., 41.7 parts by weight of an isocyanate compound (isocyanate index =
0.85) and 70 ppm of a catalyst were added and a polyurethane was prepared in the same manner as in Example 1.

After crushing this, under the same conditions as in Example 1, 100 parts by weight of ethylene-vinyl chloride copolymer, 150 parts by weight of dimethylcyclohexyl phthalate, 2 parts by weight of barium stearate, 1 part by weight of zinc stearate, amine capture. 1.5 parts by weight of the agent was added to the kneaded material and kneaded for 10 minutes to obtain a sheet of the intended vibration energy absorbing material. Example 4 0 parts by weight of polyester polyol and 38 parts by weight of isocyanate compound (isocyanate index =
0.85) except that the same operation as in Example 3 was performed,
The intended vibration energy absorber was obtained.

Example 5 120 parts by weight of polyester polyol, 30 parts by weight of polyester polyol, 41.9 parts by weight of isocyanate compound (isocyanate index = 0.8)
5), instead of dimethylcyclohexyl phthalate, di-2-ethylhexyl phthalate (Vinizer 80,
The same operation as in Example 3 was carried out except that 20 parts by weight of Kao Corporation was used to obtain the intended vibration energy absorber.

Example 6 Absorption of desired vibrational energy by the same procedure as in Example 5 except that 24.4 parts by weight of an isocyanate compound (isocyanate index = 0.5) and 70 parts by weight of di-2-ethylhexyl phthalate were used. I got the material.

Example 7 The same operation as in Example 6 was carried out except that the amount of the isocyanate compound was changed to 29.3 g (isocyanate index = 0.6) to obtain a desired vibration energy absorbing material.

Example 8 55 parts by weight of polyester polyol, 70 parts by weight of polyester polyol and 3 parts of isocyanate compound
The same operation as in Example 6 was carried out except that the amount was 0.5 g (isocyanate index = 0.45) to obtain the intended vibration energy absorber.

Example 9 140 parts by weight of polyester polyol, 0 parts by weight of polyester polyol and 1 part of isocyanate compound
The same operation as in Example 6 was carried out except that the amount was 4.4 g (isocyanate index = 0.5) to obtain the intended vibration energy absorber.

COMPARATIVE EXAMPLE 1 Instead of polyester polyol and and, 3-
Polyester polyol obtained by condensation polymerization of methyl-1,5-pentanediol and adipic acid (Kurapol P-510, number average molecular weight 500, manufactured by Kuraray Co., Ltd.)
95 parts by weight of an isocyanate compound
A sheet composition was obtained by the same operation as in Example 6 except that the weight part (isocyanate index = 0.85) was used.

Comparative Example 2 A sheet composition was obtained by the same procedure as in Comparative Example 1 except that the isocyanate compound was changed to 37.5 parts by weight (isocyanate index = 0.5).

Comparative Example 3 The same operation as in Example 6 was carried out except that the isocyanate compound was 17.1 g (isocyanate index = 0.35). However, it has been difficult to form a sheet by kneading a polyvinyl chloride resin and a plasticizer because the mixture is extremely sticky.

Comparative Example 4 In Example 1, only a polyvinyl chloride resin other than the polyurethane component, a plasticizer, a petroleum resin, and a stabilizer were roll-kneaded to obtain a sheet composition.

The vibration energy absorbing material and the sheet composition thus obtained were evaluated by the following methods.

[Evaluation of Loss Coefficient (tan δ)] Example
The composition obtained in Comparative Examples (excluding Comparative Example 3) was heated to 180 ° C.
And a sheet having a thickness of 0.2 mm was produced. Using this sheet, a temperature rising rate of 2 ° C./min was measured by a viscoelasticity analyzer RSAII (manufactured by Rheometrics Fast) which is a measuring device based on the non-resonance type forced vibration method.
The loss coefficient was measured at a measurement frequency of 10 Hz. Table 1 shows the peak value of the loss coefficient at this time, the temperature at that time, and the temperature range in which the loss coefficient ≧ 0.3.

[0042]

[Table 1]

[Evaluation of compression set] The compositions obtained in Examples and Comparative Examples (excluding Comparative Example 3) were pressed at 180 ° C., and test pieces for evaluation of compression set (thickness shown in JIS K6301 were prepared. 12.7 ± 0.13 mm) was produced. According to the test method of this test piece JISK6301, initial strain 25
%, After 22 hours at a temperature of 70 ° C., the strain was released and the residual strain was measured. The results are shown in Table 2.

[0044]

[Table 2]

[0045]

As is apparent from the above description, according to the present invention, by virtue of compounding a polyvinyl chloride resin with a plasticizer and a specific polyurethane, a vibration excellent in rubber properties as well as molding processability is obtained. An energy absorber is obtained.

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Claims (2)

(57) [Claims] Claims: 1. Polyurethane (a) 50-300 parts by weight and a plasticizer (b) 20-, which have a bridge structure composed of triisocyanate and polymer polyol, per 100 parts by weight of polyvinyl chloride resin. In the vibration energy absorber containing 200 parts by weight, the acid component of the polymer polyol contained in the polyurethane (a) is in the range of phthalic acid / aliphatic dicarboxylic acid = 10/0 to 1/9 (molar ratio). Vibration energy absorber made of polyurethane. 2. A polyurethane (a) having an isocyanate index (the number of isocyanates / the number of hydroxyl groups) =
The vibration energy absorbing material according to claim 1, which is made of polyurethane in the range of 0.4 to 0.7.