JPH0457835A - Vibration-absorbing foam - Google Patents

Abstract

PURPOSE:To prepare the title foam free from plasticizer bleeding and excellent in vibration energy-absorbing capacity by compounding a polyvinyl chloride resin with a specific phthalic ester and/or a specific phosphoric ester. CONSTITUTION:100 pts. wt. polyvinyl chloride resin (e.g. an ethylene-vinyl chloride copolymer resin) is compunded with 5-200 pts. wt. phthalic ester of formula I (wherein R1 and R2 are each a monocyclic hydrocarbon group) and/or 5-200 pts. wt. phosphoric ester of formula II (wherein R3, R4, and R5 are each an arom. monocyclic hydrocarbon group).

Description

[Detailed Description of the Invention] [Industrial Application Fields] The present invention improves operational reaction speed and measurement accuracy by controlling vibrations and shocks in fields such as various transportation equipment, precision electronic equipment, audio equipment, architecture, and sports. This invention relates to a polyvinyl chloride foam that has excellent vibration and shock energy absorption performance and is used for the purpose of improving sound quality, improving sound quality, or increasing comfort.

[Prior Art] Conventionally, butyl rubber has been most commonly used as a vibration energy absorbing material. In addition, recently, polynorbornene and special urethane elastomers have been discovered to have higher performance and are attracting attention. The primary evaluation of these vibration energy absorbing materials is performed using the storage modulus (E') and loss coefficient (tan δ - loss modulus (E')/storage modulus (E')) determined by measuring the viscoelasticity of the material. Ru.

In order to design a vibration energy absorbing material, the larger the loss coefficient is, the more optimal the storage modulus is depending on the form in which it is used.

These two factors are usually highly temperature dependent. That is, the storage modulus gradually decreases as the temperature increases, and usually decreases rapidly from a temperature range exceeding the glass transition point. In addition, the loss coefficient generally shows the highest value in a temperature range exceeding the glass transition point, or tends to decrease in a temperature range around the glass transition point.

Therefore, the standard required for such vibration energy absorbing materials has traditionally been that the material has a high loss coefficient in the temperature range in which it is used. On the other hand, the storage modulus can be adjusted within a considerable range by adding inorganic or metal fillers, softeners, rubber, etc., so it has been possible to adjust it to the optimum value.

Therefore, butyl rubber, polynorbornene, special urethane elastomers, etc. each have a maximum loss coefficient of t.
It shows excellent values of an δ-1, 42, 8, 1, and 3. However, these materials have difficulty in processability and moldability, and their range of use has been limited.

On the other hand, polyvinyl chloride resin has a long history as one of the five major general-purpose resins, and not only is it economical, but most molding methods have been established. Moreover, it is a non-grade resin, inorganic and
It has the advantage of being easy to combine with metal fillers and softeners.

The loss coefficient of polyvinyl chloride alone is approximately 1.1 at around 90°C.
It has a peak value of However, when 100 parts by weight of DOP, a typical plasticizer, is added to 100 parts by weight of resin, the peak temperature of the loss factor becomes about 5°C, and the peak value also decreases to about 0.7. Put it away. This phenomenon was understood to be due to the broadening of the relaxation time distribution as a result of the incorporation of different molecules into the single molecular chain of polyvinyl chloride. However, as a result of our recent studies, when a very limited type of plasticizer, typified by dicyclohexyl phthalate, is added to polyvinyl chloride, the peak temperature of the loss factor decreases, and the peak value reaches about 1.6. was found to increase. However, if this dicyclohexyl phthalate is added alone to polyvinyl chloride at 70 wt% or more, or if 30 wt% or more is added to polyvinyl chloride,
Even if the amount added is less than t%, it has the fatal disadvantage of bleeding when mixed with DOP or the like. In addition, although foams are often used as vibration and shock absorbing materials, polyvinyl chloride paste resins are often used in this field. However, polyvinyl chloride paste resin is usually mixed as a liquid plasticizer and used in the form of a sol, but dicyclohexyl phthalate is solid at room temperature, so it has the disadvantage of being difficult to use.

[Invention or Problem to be Solved] The purpose of the present invention is to provide a vibration shock absorbing foam that does not cause the plasticizer bleed phenomenon and has excellent vibration energy absorption performance while taking advantage of the characteristics of polyvinyl chloride resin. shall be.

[Means for Solving the Problems] The gist of the present invention is to provide vibrations made of a polyvinyl chloride resin and a phthalate ester having the structure (i) below and/or a phosphate ester having the structure (if) below. Regarding shock absorbing foam.

Details will be explained below.

The polyvinyl chloride resin used in the present invention is a vinyl chloride homopolymer, a copolymer with vinyl acetate or ethylene, or a graft polymer with an ethylene/vinyl acetate copolymer or polyurethane. It refers to paste resins that can be generally recognized as polyvinyl chloride resins, and in particular, to obtain foam, polyvinyl chloride paste resins used for wallpaper and cushion floors are desirable.

The phthalate ester having the structure of general formula i) is R,
, R2 is a compound consisting of a C3 to C8 monocyclic hydrocarbon. R,, R, may be the same or different, and hydrogen on the ring may be substituted with another substituent.

R,, R2: Monocyclic hydrocarbon R2-R5: Aromatic monocyclic hydrocarbon Specifically, dicyclohexyl phthalate (DCHP),
Examples include dimethyl cyclohexyl phthalate, diphenyl phthalate (DPP), etc., and dimethyl cyclohexyl phthalate is preferred because it is liquid. From the viewpoint of processability and economical efficiency, the amount added is desirably 5 parts by weight or more and 200 parts by weight or less, and more preferably 10 parts by weight or more and 100 parts by weight or less, based on 100 parts by weight of the polyvinyl chloride resin.

In the case of polyvinyl chloride alone, when the dynamic viscoelasticity is measured at a frequency of 10 Hz, the maximum value of tan δ is 1.1 at about 90 °C, but depending on the amount added within this range, the maximum value of tan δ is 1.1 at a temperature of 30 °C to 8 °C.
The maximum value of tan δ is about 1.4 to 1.8 in the range of 0°C. According to relaxation phenomenology, this phenomenon is understood to be due to the homogenization of the internal state of the material and the narrowing of the relaxation time distribution, but it is unclear why this particular phthalate ester is uniquely superior. It is.

As the phosphoric acid ester having the structure of general formula (N),
It is a compound in which R3 to R5 are C6 to C9 aromatic monocyclic hydrocarbons. R3 to R9 may be the same or different, and hydrogen on the ring may be substituted with another substituent.

OR3 0-P-OR4(ii) \ OR.

Specific examples include tricresyl phosphate (TCP) and tricylenyl phosphate (TXP). In particular, trixylenyl phosphate is liquid and can compensate for the drawbacks of solid dicyclohexyl phthalate, and even when added alone to polyvinyl chloride resin, it has the excellent feature of maintaining the maximum value of tan δ of about 1.1. It has both.

The amount of phosphoric acid ester added is desirably 5 to 200 parts by weight, and more preferably 10 to 100 parts by weight, based on 100 parts by weight of the polyvinyl chloride resin from the viewpoint of processability and economy. The bleed phenomenon of phthalate ester can be significantly suppressed by adding 5 parts by weight or more of phosphate ester.

In this composition, by adjusting the blending amounts of phthalate ester and phosphate ester, the temperature at which tan δ shows the maximum value can be set over a wide range from room temperature to about 80°C, and the value should also be 1.2 or more. It can be said to be extremely useful as a vibration energy absorbing material.

As a blowing agent, use an organic blowing agent such as azodicarbonamide, azobisisobutyronitrile, or 4,4-oxybisbenzenesulfonyl hydrazide in an amount of 0.3 parts by weight or more and 20 parts by weight per 100 parts by weight of polyvinyl chloride resin. Preferably below 100 yen.

If it is less than 0.3 parts by weight, the magnification will be poor, and if it exceeds 20 parts by weight, there is no point.

Furthermore, the effect of the phosphoric acid ester makes it possible to suppress the bleeding phenomenon of the phthalic acid ester, and maintains the excellent characteristics of polyvinyl chloride resin. Therefore, the present composition can be molded into any shape by processing methods such as calendering, compression molding, injection molding, etc., which are commonly used for polyvinyl chloride resins. Particularly, in order to obtain a foam, a polyvinyl chloride paste resin and these plasticizers may be mixed and made into a sol, which may be coated on a substrate and foamed in a foaming furnace.

The resin composition according to the present invention also contains calcium carbonate and talc, which are commonly used in polyvinyl chloride.

Fillers such as mica and graphite, flame retardants such as antimony trioxide, and further plasticizers can be added.

In addition, polymer materials commonly used for general modification of polyvinyl chloride resin such as polyvinyl acetate, ethylene vinyl acetate copolymer, and acrylonitrile-butadiene rubber, as well as coumaron resin and xylene resin, which are conventionally effective in absorbing vibration energy, are also available. It is also possible to blend it with polymeric materials that are considered to be

Additionally, adding petroleum resin is also effective in improving tanδ.

The petroleum resin used in the present invention is obtained by polymerizing 05 to C olefins in a mixed state. However, the maximum value of the loss coefficient increases (improves) by adding petroleum resin, but the degree of this effect varies considerably depending on the composition and molecular weight. In other words, petroleum resin contains 50 wt% or more of C9 components indene and styrene. It is preferable that the ratio of indene and styrene is at least half of styrene.Also, it is preferable that the number average molecular weight is 500 or more and 1500 or less.If it is out of these ranges, the value of the loss factor will be descend.

The vibration-absorbing material according to the present invention can be applied directly to parts of automobiles, industrial equipment, etc. that experience strong vibrations to suppress vibrations, or
It is used for the legs of precision equipment to prevent the propagation of vibrations from the floor.

It can also be laminated between wooden boards to improve the soundproofing properties of the wooden floor.

[Example] Hereinafter, the present invention will be explained by giving examples.

Example 1 Ethylene/vinyl chloride copolymer resin (Lyuron E-22
00) [manufactured by Tosoh Corporation 1100 parts by weight, TXP (tricylenyl phosphate) [manufactured by Ohe Chemical Industry Co., Ltd.] 40 parts by weight, DCHP (dicyclohexyl phthalate) [manufactured by Osaka Organic Chemical Co., Ltd.] ] 35 parts by weight, 2 parts by weight of barium stearate as a heat stabilizer, 1 part by weight of zinc stearate, and an azo compound (A C# R) as a blowing agent.
6.5 parts by weight [manufactured by Hydration Kasei Kogyo Co., Ltd.] was mixed with 34 parts by weight of (FL-21) [manufactured by Adeka Argus Chemical Co., Ltd.] as a foaming stabilizer and formed into a sheet using a roll forming machine. .

This roll sheet is processed into a 1-inch thick flat sheet using a press molding machine.
A soto sheet was prepared, and the dynamic viscoelasticity was evaluated using a dynamic viscoelasticity measuring device (Onoku Iblon manufactured by Oriente Nku Co., Ltd.). Furthermore, this sheet was foamed in an atmosphere at 200°C to obtain a foam with a thickness of 5IIIm, and the impact absorption property was evaluated.

Example 2 Vinyl chloride resin (Ryuron Paste R-725) [manufactured by Tosoh Corporation, 100 parts by weight, TXP (tricylenyl phosphate) [manufactured by Daihe Kagaku Kogyo Co., Ltd., 80 parts by weight, DMCHPC dimethyl cyclohexyl phthalate) [manufactured by Henkel Hakusui Co., Ltd.] 40 parts by weight, DOP (di-2-ethylhexyl phthalate) [manufactured by Kao Corporation]
AC-113 [ADEKA・
12 parts by weight, manufactured by Argus Chemical Co., Ltd., antimony trioxide (Atotsu-S) as a flame retardant; 32 parts by weight, manufactured by Nippon Choko Co., Ltd.; azo compound (AC#R) as a blowing agent;
[Mix 2 parts of Coro, 5-weight, manufactured by Hydration Kasei Kogyo Co., Ltd., and 34 parts by weight of (FL-21), manufactured by Adeka Argus Chemical Co., Ltd. as a foaming stabilizer, and apply on release paper using a knife coater. It was coated to a thickness of 11 and heated at 150° C. for 1 minute to form a gelled sheet.The dynamic viscoelasticity was measured under the same conditions as in Example 1. Further, this sheet was foamed in an atmosphere at 200° C. to obtain a foam with a thickness of 5 nm+m, and its impact absorption properties were evaluated.

Example 3 Of the composition of Example 2, 60 parts by weight of TXP (tricylenyl phosphate) [manufactured by Daihe Kagaku Kogyo Co., Ltd.], DMC
HP (dimethylcyclohexyl phthalate) [manufactured by Henkel Hakusui Co., Ltd.] 20 parts by weight, DOP (di-2-ethylhexyl phthalate) [manufactured by Kao Corporation, changed to 0 parts by weight 1, according to Example 1. Sheets and foams were prepared and their dynamic viscoelasticity and shock absorption properties were measured.

Comparative Example] Of the composition of Example 2, 0 parts by weight of TXP (tricylenyl phosphate) [manufactured by Daihe Kagaku Kogyo Co., Ltd.], DMC
HP (dicyclohexyl phthalate) [manufactured by Osaka Organic Chemical Co., Ltd., 30 parts by weight was changed to DOP (di-2-ethylhexyl phthalate) [manufactured by Kao Corporation] 70 parts by weight, and a sheet was prepared according to Example 1. A foam was prepared and its dynamic viscoelasticity and shock absorption properties were measured.

(Evaluation of Loss Factor) The loss factor (tan δ) of the sheets obtained in Examples 1, 2.3 and Comparative Example was measured using a dynamic viscoelasticity measuring device (Rheopybron manufactured by Orientic Co., Ltd.). The measurement conditions were a measurement frequency of 11.0 Hz and a heating rate of 1'C/mjn.
I went there. Table 1 shows the maximum value of tan δ and the temperature at that time.

(Measurement of Shock Absorption Performance of Foam) A comb board with a thickness of 3 mm was laid on a steel plate with a thickness of 30 mm, and the foams obtained in Examples 1 and 2.3 and Comparative Example 1 were placed thereon. At the same position, a vibration pickup (manufactured by BrLel & Kjir) was attached to the back side of the steel plate, and a steel ball weighing 1A 388.7g with a force transducer (manufactured by BrVel & Kjζr) was dropped from a height of 300 mm onto the foam. I let it happen. At that time, the impact acceleration measured using a vibration pickup and a force transducer was measured as a voltage value and is shown in Table 1.

[Effects of the Invention] As is clear from the above explanation, the foam obtained by adding a specific phosphoric acid ester and a specific phthalic acid ester has a
anδ is extremely large, exceeding 1.0, and as a result, the ratio of impact transmission (voltage value detected by the vibration pickup) and the ability to softly receive impact (voltage value detected by the force transducer) are both 20% to 60%. Improvement effects have been obtained.

Claims (1)

[Claims] (1) From 5 to 200 parts by weight of a phthalate ester having the following structure (i) and/or 5 to 200 parts by weight of a phosphoric acid ester having the following structure (ii) based on 100 parts by weight of the polyvinyl chloride resin. Vibration and shock absorbing foam. (i) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (ii) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ R_1, R_2: Monocyclic hydrocarbons R_3 to R_5: Aromatic monocyclic hydrocarbons