JPH0931296A - Thermoplastic resin composition - Google Patents

Abstract

(57) [Summary] [Object] To provide a thermoplastic resin composition having an excellent balance of mechanical properties, rigidity, and vibration damping properties, which is useful as a vibration damping material in a wide temperature range. [Structure] (A) A rubber-modified thermoplastic resin obtained by polymerizing an aromatic vinyl compound, a vinyl cyan compound and / or a monomer containing a (meth) acrylic acid ester as a main component in the presence of a rubbery polymer. , (B) block copolymer and / or hydrogenated product thereof, and (C) polymer (a) comprising aromatic vinyl and vinyl cyan compound and polymer (b) obtained by polymerizing aromatic vinyl compound A copolymer (c-1) and / or a polymer (a) and α-
A thermoplastic resin composition comprising a copolymer (c-2) comprising a polymer (C) obtained by polymerizing an olefin monomer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic resin composition which comprises rubber-modified thermoplastic resin and thermoplastic elastomer as essential components and is excellent in mechanical properties and vibration damping properties.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for a comfortable living environment, and there is a demand for suppressing vibration and reducing noise from equipment in the living environment. In addition, in audio equipment and household appliances, there are fields in which higher quality sound is required, and new materials with excellent vibration damping characteristics are expected to appear.
Conventionally, for the purpose of vibration control and noise reduction, there are examples of using a damping steel sheet that is made by applying a flexible rubber-like composition to a steel sheet and curing it, or using polypropylene that has an excellent loss tangent (tan δ) near room temperature. To be However, the vibration-damping steel plate is expensive due to its complicated working process, and is heavy, so it can be used only for limited purposes. Further, polypropylene has a low flexural modulus and can be used only for a limited number of applications as a structure, and there is a problem that it is difficult to obtain a molded product with high dimensional accuracy due to a large molding shrinkage of a crystalline resin. . By the way, in general, mechanical properties, moldability, workability, etc. are good. Therefore, rubber-modified styrene resins such as ABS used for various structural materials and housing materials have an actual operating temperature due to their molecular structure. Vibration damping performance is relatively low near a certain room temperature, and improvement of vibration damping performance is desired. Mechanical properties of the rubber-modified styrenic resin are improved by simply adding a component that imparts vibration damping property in order to improve the vibration damping performance, for example, a polymer as disclosed in JP-A-2-102212 or JP-A-2-300218. In particular, there is a problem that impact resistance is significantly reduced.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and it is excellent in impact resistance and rigidity, and is excellent in vibration damping property and vibration absorbing property of structural materials, acoustic parts and the like. It is an object of the present invention to provide a thermoplastic resin composition that can be used in a wide range of required applications.

[0004]

Means for Solving the Problems The inventors of the present invention have earnestly made efforts to solve the above problems, and as a result, have conceived a thermoplastic resin composition having the following constitution. (A) Graft weight obtained by polymerizing an aromatic vinyl compound, a vinyl cyan compound and / or a (meth) acrylic acid ester in the presence of a rubbery polymer, and optionally other copolymerizable monomer 40 to 96% by weight of a rubber-modified thermoplastic resin composed of a polymer or the graft polymer and a (co) polymer of the above monomer (B) an aromatic vinyl-conjugated diene block copolymer and / or its hydrogen Additives 3-39 wt% (C) Contains a polymer component (a) obtained by polymerizing an aromatic vinyl compound and a vinyl cyan compound and a polymer component (b) obtained by polymerizing an aromatic vinyl compound. The copolymer (c-1) and / or the copolymer (c-2) containing the polymer component (ii) and the polymer component (iii) obtained by polymerizing the α-olefin monomer. ) 1 to 30% by weight Serial consists (A) + (B) + (C) = 100 wt%,
A thermoplastic resin composition having a flexural modulus at 25 ° C. of 10,000 kg / cm ² or more and a loss tangent (tan δ) at 25 ° C. of 0.04 or more.

The present invention will be specifically described below. The rubber-modified thermoplastic resin used as the component (A) of the present invention can be copolymerized with an aromatic vinyl compound, a vinyl cyanide compound and / or a (meth) acrylic acid ester and, if necessary, in the presence of a rubbery polymer. A graft polymer obtained by polymerizing another monomer, or a (co) polymer of the above-mentioned monomer and the above-mentioned monomer.

Examples of the rubber-like polymer include polybutadiene, butadiene-styrene copolymer, polyisoprene, butadiene-acrylonitrile copolymer, ethylene-propylene- (diene) copolymer, ethylene-butene-1- (diene. ) Copolymer, isobutylene-isoprene copolymer, acrylic rubber, styrene-butadiene-styrene block copolymer, styrene-butadiene-styrene radial teleblock copolymer, styrene-isoprene-styrene block copolymer, SEBS, etc. Examples thereof include hydrogenated diene-based (block, random and homo) polymers, polyurethane rubber, silicone rubber and the like. Among these, polybutadiene, butadiene-styrene copolymer, ethylene-propylene- (diene) copolymer, ethylene-butene-1- (diene) copolymer,
Hydrogenated diene polymers and silicone rubbers are preferred.

Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-methylstyrene,
Examples thereof include m-methylstyrene, p-methylstyrene, α-ethylstyrene, methyl-α-methylstyrene, dimethylstyrene, monobromostyrene, dibromostyrene, tribromostyrene, chlorostyrene and dichlorostyrene. Among these, styrene, α-
Methylstyrene and p-methylstyrene are preferred.
Examples of the vinyl cyanide compound include acrylonitrile and methacrylonitrile. Of these, acrylonitrile is preferred. Above (meta)
Examples of the acrylate ester include methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and the like. Of these, methyl methacrylate is preferred.

The above-mentioned other copolymerizable vinyl monomer is added to 3
It is also possible to copolymerize 0% by weight or less. As these monomers, maleic anhydride, itaconic anhydride, acid anhydride compounds such as citralonic anhydride, maleimide, N-methylmaleimide, N-butylmaleimide, N- (p-methylphenyl) maleimide, N- Phenylmaleimide, N
-Maleimide compounds of α- or β-unsaturated dicarboxylic acids such as cyclohexylmaleimide, unsaturated epoxy compounds such as glycidyl methacrylate and allyl glycidyl ether, unsaturated carboxylic acid amides such as acrylamide and methacrylamide, acrylic amine, amino methacrylate Amino group-containing unsaturated compounds such as methyl, aminoethyl methacrylate, aminopropyl methacrylate and aminostyrene; hydroxystyrene, 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4-hydroxy-2- Butene, trans-4-hydroxy-2-butene, 3-hydroxy-2-methyl-1-
Unsaturated compounds containing hydroxyl groups such as propene, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate; unsaturated acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid and oxazoline group-containing unsaturated compounds such as vinyl oxazoli. Etc., and these are used in one kind or two or more kinds.

The amount of the component (A) used in the thermoplastic resin composition of the present invention is 40 to 96% by weight, preferably 50 to 90% by weight, more preferably 60 to 85% by weight.
% By weight. If the amount used is less than 40% by weight, the impact strength is poor, and if it exceeds 96% by weight, the vibration damping performance is poor. The amount of the rubber-like polymer in the component (A) of the present invention is preferably 5 to 80% by weight, more preferably 10 to 70% by weight from the viewpoint of impact resistance.
% By weight. The component (A) of the present invention can be produced by known polymerization methods such as emulsion polymerization, solution polymerization, suspension polymerization and bulk polymerization. The graft ratio in the graft copolymer is preferably 5 to 200% by weight, more preferably 1
It is 0 to 150% by weight. The intrinsic viscosity (η) (methyl ethyl ketone, measured at 30 ° C.) of the methyl ethyl ketone-soluble component is preferably 0.1 to 1.2 dl / g, more preferably 0.2 to 0.8 dl / g.

The block copolymer used as the component (B) of the present invention is a block (I) composed of a vinyl aromatic compound and a block (II) composed of a conjugated diene compound.
The block binding form is I- (II-
I) _n , or (I-II) _n , and X- (II-I)
_It is represented by _n (n is an integer of 1 or more, X is a coupling agent residue) and is not particularly limited. The block (I) composed of a vinyl aromatic compound is a copolymer of a vinyl aromatic compound alone or a vinyl aromatic compound and a conjugated diene compound containing 60% by weight or more, preferably 80% by weight or more of a vinyl aromatic compound. It has a block structure. On the other hand, the block (II) composed of a conjugated diene compound is
The conjugated diene compound block is a conjugated diene compound alone or a copolymer block of a conjugated diene compound and a vinyl aromatic compound containing the conjugated diene compound in an amount of 60% by weight or more, preferably 80% by weight or more. May have a structure having one or more so-called tapered blocks that are randomly connected or gradually increased. The 1,2 bond and 3,4 bond content of the conjugated diene compound is 10% or more, preferably 20% or more, more preferably 30% or more. A high content of 1,2 bonds and 3,4 bonds is preferable because it improves the vibration damping property near room temperature.

As the vinyl aromatic compound, styrene,
There are t-butyl styrene, α-methyl styrene, p-methyl styrene, α-ethyl styrene, methyl-α-methyl styrene and the like, and these are used alone or in combination of two or more. Of these, styrene is particularly preferable. Examples of the conjugated diene compound include butadiene, isoprene, pentadiene and the like, and these are used alone or in combination of two or more. Of these, butadiene and isoprene are preferable, and isoprene is particularly preferable.
The block copolymer of the component (B) of the present invention has a number average molecular weight of 10,000 to 500,000, preferably 30,000 to 4
00000, particularly preferably 70,000 to 300,000
It is. The vinyl aromatic compound in the block copolymer is
Preferably 1-70% by weight, more preferably 5-50
%, Particularly preferably 10 to 30% by weight. Further, as the block copolymer, a hydrogenated product of the above block copolymer may be used, or a block copolymer composed of a hydrogenated block (II) composed of the conjugated diene compound may be used. The amount of component (B) used in the resin composition of the present invention is 3 to 39% by weight, preferably 5 to 30% by weight, and more preferably 7%.
~ 25% by weight. If the amount used exceeds 39% by weight, the rigidity decreases, and if it is less than 3% by weight, the composition obtained is not sufficiently vibration-damping, which is not preferable.

The copolymer used as the component (C) of the present invention is obtained by polymerizing the aromatic vinyl compound and the polymer component (a) obtained by polymerizing the aromatic vinyl compound and the vinyl cyan compound. Copolymer (c-1) containing polymer component (b) and / or polymer component (a)
And a copolymer component (c-2) containing a polymer component (c) obtained by polymerizing an α-olefin monomer, and is a block or graft copolymer. In the case of a block copolymer, the morphology of the block bond is a- (loi) _n ,
(I-ro) _n , X- (Loi) _n or I- (Ha-
A) _n , (i-ha) _n , X- (hai) _n (n is an integer of 1 or more, X is a coupling agent residue), and is not particularly limited. In the case of a graft copolymer, one of the polymer (a) or the polymer (b) or the combination of the polymer (a) or the polymer (c) has a main chain skeleton and the other has a side chain. It forms a chain and is not particularly limited. Further, in the graft copolymer, one polymer is dispersed in the other polymer, the particle size of the dispersion is 0.001 to 10 μm, and the graft ratio is at least 1% by weight or more. It is preferably a thermoplastic resin.
The ratio of each polymer is (a) / (b) or (a) / (c)
= 10 to 90/90 to 10% by weight, and more preferably 30 to 70/70 to 30% by weight. Also,
The molecular weights of the components (c-1) and (c-2) are preferably in the range of 50,000 to 500,000, respectively.

As the aromatic vinyl compound and vinyl cyan compound used in the component (C) of the present invention, all of those described above are used. The α-olefin monomer is ethylene, propylene, butene-1, hexene-1, octene-1,
4-methylpentene-1 and the like can be mentioned. Of these, propylene and butene-1 are preferable, and propylene is particularly preferable. The amount of the component (C) used in the thermoplastic resin composition of the present invention is 1 to 30% by weight, preferably 3 to 25% by weight, more preferably 5 to 20% by weight. If the amount used exceeds 30% by weight, the impact resistance and the vibration damping property decrease, and if it is less than 1% by weight, the impact resistance of the resin composition decreases, which is not preferable.

The flexural modulus at 25 ° C. of the thermoplastic resin composition of the present invention is preferably 10,000 kg / c.
m ² or more, more preferably 15,000 kg / cm ² or more, particularly preferably 20,000 kg / cm ² or more, is less than 10,000 kg / cm ^2, the stiffness is not suitable for use as insufficient structural material . The loss tangent (tan δ) of the composition of the present invention at 25 ° C. is preferably 0.04 or more, more preferably 0.05 or more, and particularly preferably 0.06 or more. Loss tangent (t
When an δ) is less than 0.04, the vibration damping performance is poor. When the loss tangent at 25 ° C. is 0.04 or more, excellent vibration damping properties can be exhibited when used near room temperature. By properly selecting or combining the kind and amount of the component (A), the kind and amount of the component (B), the kind and amount of the component (C), and the kind and amount of the filler of the present invention, The flexural modulus and loss tangent (tan δ) of the thermoplastic resin composition of the invention can be adjusted within the range of the present invention.

The composition of the present invention is generally used in a resin composition such as an antistatic agent, an antioxidant, a flame retardant, an ultraviolet absorber, a photo-oxidation inhibitor, a coloring agent and a lubricant, if necessary. Additives can be added.

Further, in order to improve the vibration damping performance and the mechanical properties of the composition of the present invention, wood flour may be blended if necessary. The wood powder is not particularly limited, but in order to improve the appearance of a molded product of the obtained composition, it is preferable that the particle size is smaller than the large particle size. It is preferable to use wood flour after treating it with an alkaline solution in advance in order to maintain thermal or temporal stability of the resulting composition. As the alkaline liquid, hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide may be used. In addition, the wood powder may be used after being treated with an alkali, dried, impregnated with an arbitrary thermosetting resin monomer, cured, and crushed. By carrying out this process, a relatively large amount of wood flour can be added to the composition of the present invention. In addition to wood flour, the same fibrous material, for example, rice husk or paper finely crushed, can be used in the same manner as above. The fibrous material such as wood powder may be used alone and / or as a mixture of plural kinds. As the usage amount,
The total amount of components (A) to (C) is 100 parts by weight, preferably 2 to 100 parts by weight, more preferably 5 to 60 parts by weight, and particularly preferably 7 to 50 parts by weight.

Further, an inorganic filler may be used for the purpose of improving the mechanical properties of the composition of the present invention. Specific examples of the inorganic filler, glass fiber, glass flakes, glass beads, hollow glass beads, glass milled fiber, mica, talc, calcium carbonate, kaolin, silica, carbon fiber, potassium titanate whiskers,
Examples thereof include zinc oxide whiskers, titanium oxide whiskers, aluminum borate whiskers, wollastonite, aluminum hydroxide and magnesium hydroxide, and any of them can be preferably used according to the purpose. These inorganic fillers can be used alone and / or as a mixture of plural kinds. The amount used is preferably 5 to 100 parts by weight, more preferably 10 to 50 parts by weight, based on 100 parts by weight of the total of the components (A) to (C).

To produce the composition of the present invention, a Banbury mixer, Brabender, plastomill, kneader,
Mixing can be carried out using various devices generally used in kneading machines for thermoplastic resins, such as a vented extruder, but a method using a vented extruder is particularly preferred. In particular, when an inorganic filler is blended, a method of using a twin-screw extruder or a continuous kneader is preferable. The kneading temperature depends on the composition, but is usually 1
It is preferably carried out within the range of 80 to 300 ° C.

[0019]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist of the present invention is not exceeded. In the examples, parts and% are based on weight unless otherwise specified.
In addition, various evaluations in the examples were measured by the following methods. Impact resistance Izod impact (IZ) at room temperature (+ 25 ° C) was measured according to ASTM D256. The unit is kgf
cm / cm. Melt Flow Rate (MFR) Measured according to ASTM D1238. Unless otherwise specified, the measurement temperature and conditions were 220 ° C. and 10 kg load. The unit is g / 10 min. Bending test The bending elastic modulus was measured according to JIS K7203. The unit is kg / cm ² . tanδ (loss tangent) viscoelasticity measuring device [Toyo Baldwin Co., Ltd., DDV
III EP] using a frequency of 11 Hz and a measurement temperature of -11
It measured at 0 degreeC- + 100 degreeC and the temperature rising rate of 2 degreeC / min.

Rubber-like Polymers (a) -1 to (a) -3 The rubber-like polymers shown in Table 1 were used as the component (a) used in the rubber-modified thermoplastic resin (A) of the present invention. Preparation of Resins (A) -1 to (A) -7 In the presence of the rubbery polymers (a) -1 to (a) -3, a resin obtained by graft-polymerizing various monomers and a rubbery polymer were allowed to exist. Instead, resins obtained by polymerizing only the monomer components were obtained. The compositions of these resins are shown in Table 2.

Aromatic vinyl-conjugated diene block copolymer
The following were used as the aromatic vinyl-conjugated diene block copolymer and / or its hydrogenated product as the component (B) component. (B) -1; Styrene-isoprene-styrene block copolymer "HIBLER VS-1" manufactured by Kuraray Co., Ltd., styrene content 20%, 1, (3,4) -bond 70% (B) -2; Hydrogenated product of styrene-isoprene-styrene block copolymer "HIBLER HVS-3" manufactured by Kuraray Co., Ltd., styrene content 20%, 1, (3,4) -55% (B) -3; styrene-butadiene -Hydrogenated product of styrene block copolymer Using styrene, butadiene and an organolithium compound, a copolymer was obtained by bulk polymerization and then hydrogenated. Styrene content 25%, 1,2-bond 85% In addition, the hydrogenation rates of (B) -2 and (B) -3 are all 90% or more.

Preparation of component (C) of the present invention The copolymer of Table 3 was used as the component (c-1) of the present invention. These are block copolymers obtained by solution polymerization.
The component (c-2) of the present invention was obtained by the following production method. Pure water was put into a stainless steel autoclave, and polyvinyl alcohol was added and dissolved as a suspending agent. Polypropylene or polyethylene was put in this and stirred to disperse. Separately, benzoyl peroxide as a radical polymerization initiator, t-butylperoxymethacryloyloxyethyl carbonate as a radically polymerizable organic peroxide, and styrene and acrylonitrile as vinyl monomers are dissolved, and this solution is put into the autoclave. It was stirred. Next, the autoclave was heated to 60 to 65 ° C. and stirred for 2 hours to impregnate polypropylene or polyethylene with a vinyl monomer containing a radical polymerization initiator and a radically polymerizable organic peroxide. Then, the total amount of the impregnated vinyl monomer, radically polymerizable organic peroxide and radical polymerization initiator is 10% of the initial amount.
After confirming that the temperature is above, set the temperature to 80-85.
C. and maintained at that temperature for 7 hours to complete the polymerization,
It was washed with water and dried to obtain a grafted precursor. Next, this grafted precursor was extruded at 200 ° C. with a single-screw extruder to obtain the component (c-2) of the present invention. Observation with a scanning electron microscope revealed that the spherical resin having a particle size of 0.3 to 0.4 μm was uniformly dispersed. A copolymer having the composition shown in Table 4 was obtained by the above method. Filler (D) The following (D) -1 and (D) -2 were used as the filler components. (D) -1; Mica manufactured by Yamaguchi Mica Industry Co., Ltd. (A-2
1) (D) -2; manufactured by Keiwa Furnace Co., Ltd., Wollastonite (Cycatech H-08)

Examples 1 to 16 and Comparative Examples 1 to 6 A kneading machine having a formulation shown in Table 5 (manufactured by Buss, Ko-
Kneader MKD 46] and granulate at 90 ° C
After drying with an injection molding machine [Toshiba Machine Co., Ltd., IS
80A] was used to fabricate a test piece and the physical properties were evaluated. Dynamic viscoelastic test piece is 1 ~ 1.2mm thick
A strip-shaped sample having a length of 50 mm and a width of 7 mm was cut out from the molded plate of (1) and used.

As is clear from Table 5, Examples 1 to 16
While the composition of the present invention having excellent mechanical properties,
It can be seen that the composition exhibits excellent vibration damping properties at room temperature. On the other hand, Comparative Example 1 is an example in which the amount of the component (A) used in claims is small outside the scope of the present invention, and the impact resistance is poor. Comparative Example 2 is an example in which the amount of the component (A) used in claims is large outside the scope of the present invention, and the vibration damping property at room temperature (+ 25 ° C.) is poor. Comparative Example 3 is an example in which the amount of the component (B) used in claims is small outside the scope of the present invention, and is room temperature (+ 25 ° C.).
Vibration control performance is poor. Comparative Example 4 is an example in which the amount of the component (B) used in claims is large outside the range of the present invention, and the bending elastic modulus is low and the rigidity is poor. Comparative Example 5 is an example in which the amount of the component (C) used in the claims is small outside the scope of the present invention, and the impact resistance is poor. Comparative Example 6 is an example in which the amount of the component (C) used in claims is large outside the scope of the present invention, and the impact resistance and room temperature (+2
Damping property at 5 ° C) is poor.

[0025]

Industrial Applicability The thermoplastic resin composition of the present invention has an excellent balance of mechanical strength, rigidity, and vibration damping property. For example, a housing material for incorporating a device for rotating or vibrating such as a motor or a component thereof. , Or the speaker diaphragm or its frame and the housing of the speaker body, which are required to have appropriate vibration damping characteristics and rigidity, and OA / home appliances field, electric / electronic field, where vibration is considered to be reduced in the usage environment, It can be used for various parts such as miscellaneous goods field, sanitary field and automobile field.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

[Table 5]

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Hisao Nagai 2-11-24 Tsukiji, Chuo-ku, Tokyo Inside Nippon Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. An aromatic vinyl compound and a vinyl cyan compound and / or (meth) in the presence of (A) a rubbery polymer.
Graft polymer obtained by polymerizing an acrylic ester and, if necessary, other copolymerizable monomer, or rubber-modified thermoplastic resin comprising the graft polymer and a (co) polymer of the above monomer Resin 40 to 96% by weight (B) Aromatic vinyl-conjugated diene block copolymer and / or hydrogenated product thereof 3 to 39% by weight (C) Heavy obtained by polymerizing aromatic vinyl compound and vinyl cyan compound Copolymer (c-1) containing polymer component (b) obtained by polymerizing coalescence component (a) and aromatic vinyl compound and / or polymer component (a) and α-olefin monomer 1 to 30% by weight of a copolymer (c-2) containing a polymer component (C) obtained by polymerizing a body, and comprising (A) + (B) + (C) = 100% by weight. ,
A thermoplastic resin composition, which has a flexural modulus at 25 ° C. of 10,000 kg / cm ² or more and a loss tangent (tan δ) at 25 ° C. of 0.04 or more.