JPH02289645A - Vibration-damping material - Google Patents

Abstract

PURPOSE:To obtain a vibration-damping material having high elasticity, high heat resistance and excellent vibration damping performances in a wide temperature range, comprising a crystalline polymer containing a 4-hydroxybenzoic acid unit but not a naphthalene ring and a liquid crystal polymer containing a naphthalene ring. CONSTITUTION:(A) A crystalline polymer comprising an aromatic polyester (amide) prepared from >=40mol%, preferably >=50mol% 4-hydroxybenzoic acid and a compound (e.g. terephthalic acid, hydroquinone or 4-aminophenol) not containing a naphthalene ring is blended with (B) 10-80wt.%, preferably 20-70wt.% liquid crystal polymer having >=15mol%, preferably >=25mol% naphthalene ring-containing constituent unit (e.g. 6-hydroxy-2-naphthoic acid or 2- hydroxy-5-aminonaphthalene) and optionally 0-70wt.% filler to give a vibration- damping material.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vibration damping material that exhibits good vibration damping properties over a wide temperature range. More specifically, the present invention relates to providing a damping material useful in the field of damping materials that require good damping properties over a wide temperature range, such as automobile parts, electrical and electronic parts, audio parts, and sports parts. It is.

[Prior Art] Damping materials made of a single thermoplastic or thermosetting resin generally have a narrow peak temperature range of loss coefficient and do not exhibit good damping performance over a wide temperature range. There is a problem when the range is wide. In order to improve this problem, for example, JP-A-57-185140, 61-162
No. 348, etc., proposes a method of laminating two types of resins having different peak temperatures of loss coefficients to improve the allocation performance over a wide temperature range. However, the materials described in these documents are general-purpose plastics and rubbers such as polyolefin and polyvinyl chloride, and cannot be used in fields that require high elasticity and high heat resistance in addition to distribution characteristics.

In recent years, attempts to use liquid crystal polymers for vibration damping materials in fields that require high elasticity and high heat resistance have been reported, for example in Japanese Patent Application Laid-Open No. 62-149296. This research focuses on damping performance near room temperature, and is not intended to provide a material with improved temperature dependence of damping performance.

Also, for example, JP-A-56-115357, 57-40
No. 550, No. 63-132967, etc., report on a blend of two or more aromatic polyesters (liquid crystal polymers) that can form an anisotropic melt phase. However, these studies are aimed at improving processability and mechanical properties, and are not intended to provide materials with improved temperature dependence of vibration damping performance.

[Problems to be Solved by the Invention] Based on the above circumstances, the present invention provides a vibration damping material that has high elasticity, high heat resistance, and good vibration damping performance over a wide temperature range.

[Means for Solving the Problems] As a result of intensive research to solve the above problems, the present inventors melted and mixed two or more different types of liquid crystal polymers containing structural units having a specific structure by a conventional method. It has been discovered that the resin composition serves as a vibration damping material that exhibits good vibration damping performance over a wide temperature range.

That is, the present invention provides a liquid crystal polymer having 40 mol% or more of 4-hydroxybenzoic acid residues as a constitutional unit and no naphthalene ring as a constitutional unit, and a liquid crystal polymer having 15 mol% or more of a constitutional unit containing a naphthalene ring. The present invention relates to a vibration damping material containing 10 to 80% by weight of a liquid crystal polymer.

The present invention will be explained in detail below.

One of the liquid crystal polymers used in the present invention is 40 mol%
The above 4-hydroxybenzoic acids, aromatic hydroxycarboxylic acids other than 4-hydroxybenzoic acid that do not have a naphthalene ring, aromatic dicarboxylic acids, aromatic diols, aromatic hydroxyamines, aromatic diamines, aromatic carboxyamines one or more compounds selected from aliphatic dicarboxylic acids, aliphatic diols, aliphatic hydroxyamines, aliphatic diamines, and aliphatic carboxyamines through ester bonds, and ester bonds and amide bonds. These are polymerized aromatic polyester and aromatic polyester amide.

Aromatic hydroxycarboxylic acids other than 4-hydroxybenzoic acid that do not have a naphthalene ring include 3-hydroxycarboxylic acid, 2-hydroxycarboxylic acid, 4-hydroxy-2-methylbenzoic acid, 4-hydroxy-3- Methylbenzoic acid, 4-hydroxy-2-phenylbenzoic acid,
2-chloro-4 monohydroxybenzoic acid, 3-chloro-4
Examples include alkyl- and halogen-substituted aromatic hydroxycarboxylic acids such as -hydroxybenzoic acid.

As an aromatic dicarboxylic acid that does not have a naphthalene ring,
Terephthalic acid, isophthalic acid, 4,4''-diphenyl dicarboxylic acid, diphenyl ether-4,4-dicarboxylic acid, diphenoxyethane-4,,41-dicarboxylic acid, diphenoxybutane-4,4- -dicarboxylic acid, diphenylmethane-3,4'-dicarboxylic acid, diphenyl ether-3,3'-dicarboxylic acid, diphenoxyethane-3,3'-dicarboxylic acid, diphenylethane-3,3
Examples include alkyl and halogen substituted products of the aromatic dicarboxylic acids, such as dicarboxylic acids, chloroterephthalic acid, promoterephthalic acid, methylterephthalic acid, and t-butylterephthalic acid.

Examples of aromatic diols having no naphthalene ring include hydroquinone, resorcinol, 4.4-dihydroxydiphenyl, 4.4-dihydroxydiphenyl ether,
3.4-dihydroxydiphenyl, 3.4=-dihydroxydiphenyl ether, 4.4-dihydroxybenzophenone, 3,4゛-dihydroxybenzophenone, 3.3゛-dihydroxybenzophenone, 4.4'' dihydroxy diphenyl sulfone, 4.4-dihydroxydiphenyl sulfide, 4.4-dihydroxydiphenylmethane, 3.4-dihydroxydiphenyl sulfone, 3.4-dihydroxydiphenyl sulfide,
3.4--dihydroxydiphenylmethane, 3.3″-
Aromatic diols such as dihydroxydiphenyl sulfone, 3.3-dihydroxydiphenyl sulfide, 3.3-dihydroxydiphenylmethane, 2.2-bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenoxy)ethane, etc. , or chlorohydroquinone,
Examples include alkyl- and halogen-substituted aromatic diols of the aromatic diols, such as promohydroquinone, methylhydroquinone, t-butylhydroquinone, 4-chlororesorcinol, and 4-methylresorcinol.

Examples of the aromatic hydroxyamine having no naphthalene ring include 4-aminophenol, 3-aminophenol, and alkyl and halogen-substituted products thereof.

Examples of the aromatic diamine without a naphthalene ring include diaminobenzene, diaminodiphenyl, and alkyl and halogen substituted products thereof.

Examples of the aromatic carboxyamine having no naphthalene ring include 4-aminobenzoic acid, 3-aminobenzoic acid, and alkyl- and halogen-substituted products thereof.

Examples of aliphatic dicarboxylic acids include cyclic aliphatic dicarboxylic acids such as trans-1,4-cyclohexanedicarboxylic acid, cis-1,4-cyclohexanedicarboxylic acid, and 1,3-cyclohexanedicarboxylic acid, and derivatives thereof.

Examples of aliphatic diols include trans-1,4-cyclohexanediol, cis-1,4-cyclohexanediol, trans-1,4-cyclohexanedimethanol,
Cis-1,4-cyclohexanedimethanol, trans-1,3-cyclohexanediol, cis-1,2-cyclohexanediol, trans-1,3-cyclohexanedimethanol, ethylene glycol, 1,4-butanediol, 1,6- Examples include cyclic, linear, or branched aliphatic diols such as hexanediol and 1,8-octanediol, and derivatives thereof.

As the aliphatic hydroxyamine, trans-1,4-
Cyclohexane hydroxyamine, cis-1,4-cyclohexane hydroxyamine, etc., and their alkyls,
Examples include halogen-substituted products.

Examples of the aliphatic diamine include trans-1,4-cyclohexane diamine, cis-1,4-cyclohexane diamine, and alkyl and halogen substituted products thereof.

As the aliphatic carboxyamine, trans-1.4-
Cyclohexane-ruboxyamine, cis-1,4-cyclohexane-ruboxyamine, etc., and their alkyls,
Examples include halogen-substituted products.

In these liquid crystal polymers, the content of 4-hydroxybenzoic acid as a structural unit is 40 mol% or more, preferably 50 mol% or more. If the content of 4-hydroxybenzoic acid is less than 40 mol%, the value of the loss coefficient attributed to 4-hydroxybenzoic acid becomes small, and high vibration damping properties may not be obtained.

The other liquid crystal polymer used in the present invention has 15 mol% or more of structural units containing naphthalene rings. There are no restrictions on the structural units containing naphthalene rings, including hydroxycarboxylic acids, dicarboxylic acids, diols,
A naphthalene ring may be included as the hydroxyamine, diamine, or carboxyamine. Further, other structural units can be appropriately selected from the structural units of the liquid crystal polymer described above.

Aromatic hydroxycarboxylic acids having a naphthalene ring include 6-hydroxy-2-naphthoic acid, 5-hydroxy-2-naphthoic acid, 6-hydroxy-5-chloro-2-naphthoic acid, 6-hydroxy-7 -chloro-2-
Naphthoic acid, 6-hydroxy-5,7-dichloro-2-
Examples include alkyl, allyl, and halogen-substituted aromatic hydroxycarboxylic acids such as naphthoic acid.

As the aromatic dicarboxylic acid having a naphthalene ring, 2
, 6-naphthalene dicarboxylic acid, and alkyl or halogen substituted products thereof.

As the aromatic diol having a naphthalene ring, 2,6
Examples include "-naphthalenediol, 1,6"-naphthalenediol, and alkyl and halogen-substituted products thereof.

Examples of the aromatic hydroxyamine having a naphthalene ring include 2-hydroxy-5-aminonaphthalene, and alkyl and halogen substituted products thereof.

As an aromatic diamine having a naphthalene ring, 2.5
-diaminonaphthalene, alkyl and halogen-substituted products thereof, and the like.

Examples of the aromatic carboxyamine having a naphthalene ring include 5-amino-2-naphthoic acid, and alkyl and halogen-substituted products thereof.

In these liquid crystal polymers, the content of structural units containing naphthalene rings is 15 mol% or more, preferably 25 mol% or more. 1 structural unit containing a naphthalene ring
If it is less than 5 mol %, the value of the loss coefficient attributed to the naphthalene ring becomes small, and high vibration damping properties may not be obtained.

The aromatic polyesters and aromatic polyesteramides composed of the above-mentioned components may or may not form an anisotropic melt phase depending on the constituent components, the composition ratio in the polymer, and the sequence distribution. However, the liquid crystal polymer used in the present invention is limited to aromatic polyesters or aromatic polyesteramides that can form an anisotropic melt phase.

There are no particular limitations on the method for producing a liquid crystal polymer using the above-mentioned heptanomer. For example, a typical manufacturing method is 4-
Examples include a method of reacting acetoxybenzoic acid with 4,4' diacetoxydiphenyl, terephthalic acid, or isophthalic acid. The reaction is generally carried out in a nitrogen stream starting at a low temperature and continuously increasing the temperature as the reaction progresses. The obtained granular product is further heated under reduced pressure or at normal pressure to
The secondary solid phase polycondensation reaction can be carried out at a temperature of 350°C. This operation increases the molecular weight and significantly improves the properties of the resulting liquid crystalline polymer.

In addition, in order to promote the above reaction, for example, Lewis acid, hydrogen halide. Catalysts such as organic acids or inorganic acid salts and antimony or germanium compounds are used at 0.01 to 1.0
Weight percentages can also be used.

Furthermore, the liquid crystal polymer used in the present invention is also one that allows measurement of intrinsic viscosity in pentafluorophenol, at a concentration of 0.1 g/di at 60°C.
The value measured at is preferably 0.5 or more, particularly 0.8 to 1
5.0 is preferred.

Furthermore, the melt viscosity of the liquid crystal polymer of the present invention is 10 to 20
,000 poise is preferred, and 20 to 10,000 poise is particularly preferred.

Note that this melt viscosity is a value measured using a Koka-type flow tester at a liquid crystal start temperature of +40° C. and a sliding speed of 1,000 (1/sec).

15 structural units containing a naphthalene ring used in the present invention
The amount of the liquid crystal polymer added is in the range of 10 to 80% by weight, preferably 20 to 70% by weight, based on the other liquid crystal polymer. If the amount added is less than 10% by weight, the effect of improving the damping properties may not be expected because the liquid crystal polymer component makes little contribution to the loss properties of the resin composition after blending. Also, the amount added is 80
If it exceeds % by weight, the contribution of other liquid crystal polymer components to the loss characteristics is small, and the vibration damping characteristics may not be improved over a wide temperature range.

In any case, it is necessary to consider the temperature dependence of the vibration damping properties of the liquid crystal polymer to be blended, and to adjust the blending amount to: A so that stable vibration damping properties can be expressed in the target temperature range.

Various substances that are generally filled in molding resin compositions can be blended into the liquid crystal polymer mixture according to the present invention. Such substances include fibrous (for example, carbon fiber, glass fiber, aramid fiber, asbestos fiber, potassium titanate fiber, etc.), scaly (mica, graphite, glass flakes, aluminum flakes, etc.), or powder (calcium carbonate, (clay, zinc sulfate, etc.) reinforcing and non-reinforcing fillers, pigments and other colorants, light and heat stabilizers, nucleating agents. Included are mold release agents, plasticizers, flame retardants, blowing agents, and other special additives such as polymer toughening agents. The blending amount of the above filler is 0 to 70% by weight.
It is preferable that

If the amount of filler added exceeds 70% by weight, processability and vibration damping properties may deteriorate, and sufficient improvement may not be achieved.

The addition method according to the present invention may be a commonly used melt-mixing technique, such as kneading using a screw extruder or a Brabender mixer.

The molten mixture obtained as described above can be used as a damping material for audio components such as speaker diaphragms, headphone diaphragm housings, optical pickup lens holders, and carriages. Examples include electrical and electronic parts such as coil bobbins, sports equipment such as skis and tennis rackets, automobile oil pans, and soundproof cover ducts.

The performance and operating temperature range required of vibration damping materials differ depending on each application, but generally the loss coefficient value is 0.04 or more, preferably 0.0 in the environmental temperature range commonly used in each application.
It is necessary that it is 5 or more, and it is also required that it has high elasticity.

The loss coefficient represents the degree to which vibrations applied to the material are attenuated.
It can be obtained as an an δ value.

[Example] Next, the present invention will be explained in more detail by showing Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 60 mol% of 4-hydroxybenzoic acid, 15 mol% of terephthalic acid, 5 mol% of isophthalic acid, and 20 mol% of 4,4'-dihydroxydiphenyl were reacted at low temperature in a nitrogen stream. A liquid crystal polymer (hereinafter referred to as liquid crystal polymer A) obtained by performing a secondary solid-state polycondensation reaction on the resulting granular product at a temperature of 200 to 350°C by continuously increasing the temperature as the reaction progresses. ) 50% by weight
and 70 mol% 4-hydroxybenzoic acid prepared according to Example ① of JP-A-54-77691, and 3
50% by weight of a liquid crystal polymer consisting of 0 mol% of 6-hydroxy-2-naphthoic acid (hereinafter referred to as liquid crystal polymer B) was kneaded for 10 minutes at a mixing temperature of 320° C. and a rotation speed of 5 Orpm using a Labo Blast Mill mixer manufactured by Toyo Seiki Seisakusho. death,
The kneaded product was molded using a high-temperature press molding machine in the presence of nitrogen.
Press molding was performed at 20° C. to obtain a molded product having a length of 5 (to), a width of 5 mm, and a thickness of 0.5 fins. This sample was measured using a dynamic viscoelasticity measuring device manufactured by Orientech Co., Ltd. (trade name "Rheovibron").
Measurement frequency: 110Hz, heating rate: 1℃/m
The loss coefficient (tanδ) was measured at i n. The temperature range with a continuous loss coefficient of 0.04 or more is -70℃
The temperature was ~140°C.

Example 2 Liquid crystal polymer A similar to Example 1 50% by weight, 50% by mole of 4-hydroxybenzoic acid, 25% by mole of 2.6-
A liquid crystal polymer (hereinafter referred to as 50% by weight of liquid crystal polymer C) was press-molded in the same manner as in Example 1, and tan δ was measured using a dynamic viscoelasticity measuring device. The temperature range with a continuous loss factor of 0.04 or more was -60°C to 140°C.

Example 3 60 mol% 4-hydroxybenzoic acid and 40 mol% ethylene terephthalate were mixed under reduced pressure at 150 mol%.
50% by weight of a liquid crystal polymer obtained by reacting at ~350°C (hereinafter referred to as liquid polymer D) and 50% by weight of the same liquid crystal polymer C as in Example 2 were press-molded in the same manner as in Example 1, Tan δ was measured using a dynamic viscoelasticity measuring device. The temperature range with a continuous loss coefficient of 0.04 or more was -51°C to 130°C.

Example 4 50% by weight of liquid crystal polymer D similar to Example 3 and Example 1
A similar liquid crystal polymer of 850% was press-molded in the same manner as in Example 1, and ta was measured using a dynamic viscoelasticity measuring device.
nδ was measured. The temperature range with a continuous loss coefficient of 0.04 or more was -47°C to 145°C.

Example 5 60 mol% 4-hydroxybenzoic acid, 20 mol% terephthalic acid, 16 mol% 4,4'-dihydroxydiphenyl ether, and 4 mol% 4,4'-dihydroxydiphenyl under reduced pressure , 150℃~350℃
50% by weight of the liquid crystal polymer obtained by the reaction (hereinafter referred to as liquid crystal polymer E) and 850% by weight of the same liquid crystal polymer as in Example 1 were press-molded in the same manner as in Example 1, and the dynamic viscoelasticity was measured. Tan δ was measured using the device. The temperature range with a continuous loss factor of 0.04 or more was -62°C to 157°C.

Example 6 50% by weight of liquid crystal polymer E similar to Example 5 and Example 2
50% by weight of the same liquid crystal polymer C was press-molded in the same manner as in Example 1, and ta
nδ was measured. The temperature range with a continuous loss factor of 0.04 or more was -50°C to 163°C.

Comparative Example 1 The same liquid crystal polymer A as in Example 1 was press-molded in the same manner as in Example 1, and the tan was measured using a dynamic viscoelasticity measuring device.
δ was measured. The temperature range with a continuous loss factor of 0.04 or more was -55°C to 30°C.

Comparative Example 2 The same liquid crystal polymer B as in Example 1 was press-molded in the same manner as in Example 1, and tan was measured using a dynamic viscoelasticity measuring device.
δ was measured. The temperature range with a continuous loss factor of 0.04 or more was -20°C to 130°C.

Comparative Example 3 The same liquid crystal polymer C as in Example 2 was press-molded in the same manner as in Example 1, and tan was measured using a dynamic viscoelasticity measuring device.
δ was measured. The temperature range with a continuous loss factor of 0.04 or more was -30°C to 70°C.

[Effects of the Invention] According to the present invention, it is possible to obtain a damping material that has high elasticity, high heat resistance, and exhibits good damping performance at the environmental temperature at which the damping material is normally used.

Claims (1)

[Claims] (1) 4-hydroxybenzoic acid residue as a structural unit
A liquid crystal polymer having 0 mol % or more and not having a naphthalene ring as a structural unit, and a liquid crystal polymer having 15 mol % or more of a naphthalene ring-containing structural unit 10 to 80
A damping material made by adding % by weight.