JP3310333B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a resin composition having excellent vibration damping performance.

[0002]

2. Description of the Related Art In recent years, consumers have become more conscious of luxury, and quietness has become a major selling point of commodities in automobiles, office automation equipment, home electric appliances and the like. For this reason, various damping materials are used for these.

In order to improve the vibration damping performance of various plastics or elastomers, vinyl aromatic monomers and isoprene, butadiene or isoprene and butadiene are used.
It is known that a block copolymer consisting of a mixture of the above is blended and used. In the case of polypropylene, ABS resin, etc., because the affinity between the vinyl aromatic monomer and the block copolymer composed of isoprene, butadiene or a mixture of isoprene and butadiene is good, the purpose can be achieved by a two-component blend. There were many.

[0004]

[0008] However, in the case of the resin having a polar group such as e <br/> ether bond and a carbonate bond in the molecular chain, polypropylene, both in the same manner as in the ABS resin Because of the low affinity, the resulting mixture could not have sufficient physical properties such as low mechanical strength.

The present invention improves the affinity between a resin having such a polar group, a vinyl aromatic monomer and a block copolymer comprising isoprene, butadiene or a mixture of isoprene and butadiene , and contains a resin having a polar group. It is intended to obtain a vibration damping material having excellent vibration damping performance.

[0006]

According to the present invention, the above object is achieved by (a) 10 to 88 parts by weight of a polyacetal or a thermoplastic resin having a polar group which is a carbonate bond in a molecular chain; b) Block (A) comprising at least one vinyl aromatic monomer and having a number average molecular weight of 2500 to 40000
And isoprene, butadiene or a mixture of isoprene and butadiene, having a 3,4 bond and 1,2 bond content of 30% or more and a number average molecular weight of 10,000 to
A block copolymer composed of 200,000 blocks (B) and having a number average molecular weight of 30,000 to 300,000, or a hydrogenated product of 10 to 80 parts by weight, and a polymer having an affinity for the components (c) and (b) The functional group having an affinity or reactivity with the polar group of the component (a) is 0.02 to 5 with respect to the number of moles of the monomer unit in the molecule.
The problem is solved by a composition comprising 2 to 80 parts by weight of a modified polymer bonded to 0 mol%.

[0007] The composition of the present invention can be used as a material having a reduced amount of vibration and noise and improved impact resistance in a composition containing a large amount of a resin having a polar group. In the composition having a large amount of the block copolymer or the modified polymer of the component (c), the mechanical strength, heat resistance, oil resistance and the like are superior as compared with the case where the block copolymer of the component (b) is used alone. Can be used as a damping material.

Hereinafter, the present invention will be described in more detail.

[0009]

[0010] 1 of component (a) used in the present invention
One is a polyacetal include polyacetal Le is a copolymer of cyclic ethers, such as single polymer and trioxane and ethylene oxide formaldehyde.

[0011]

The resin having a carbonate bond is a condensate of a dihydroxy compound and carbonic acid, and is not particularly limited, and various polycarbonate resins are used.

[0013]

The component constituting the block (A) of the block copolymer which is the component (b) used in the present invention is an aromatic vinyl monomer, and specific examples thereof include styrene, α-methylstyrene and 1-vinylnaphthalene. , 3-
Methylstyrene, 4-propylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2-ethyl-
Examples thereof include 4-benzylstyrene and 4- (phenylbutyl) styrene, and the most preferred is styrene.

The number average molecular weight of the block (A) comprising a vinyl aromatic monomer is in the range of 2500 to 40,000. When the molecular weight is less than 2500, the performance as a composition is reduced, and when it exceeds 40000, the melt viscosity becomes too high, and the mixing with the thermoplastic resin as the component (a) does not work well, and the composition has sufficient performance. No composition is obtained.

The ratio of the block (A) comprising the vinyl aromatic monomer in the block copolymer is 5 to 5.
Those in the range of 50% by weight are preferred. If this ratio is less than 5%, the mechanical properties of the block copolymer become insufficient, while if it exceeds 50%, the viscosity becomes extremely high, and the processability such as mixing becomes difficult. In addition, the damping performance is also reduced.

The component constituting the block (B) of the block copolymer used in the present invention is isoprene, butadiene or a mixture of isoprene and butadiene .
Is preferably made of a mixture, good random, block, either tapered in the form of a block (B) in the case of using the mixture of isoprene and butadiene <br/> down.

In the block copolymer (B) of the present invention, the content of 3,4 bonds and 1,2 bonds (hereinafter sometimes collectively referred to as vinyl bond content) of the block (B) is at least 30% (100%). % May be used). If the vinyl bond content is less than 30%, sufficient vibration damping performance cannot be obtained in a normal operating temperature range, which is not preferable.

In the block copolymer, the peak temperature of the main dispersion of tan δ (loss tangent) obtained by viscoelasticity measurement is preferably -10 ° C or higher, and the peak is at a temperature lower than -10 ° C. In some cases, sufficient vibration damping performance may not be obtained in a normal temperature range.

Further, the block (B) of the block copolymer
Need to be in the range of 10,000 to 200,000. If the molecular weight is less than 10,000, the elastic properties are impaired, which is not preferable. Also, 20
If it is larger than 0000, the fluidity becomes poor, which is not preferable.

The number average molecular weight of the block copolymer used as the component (b) in the present invention is from 30,000 to 3,000.
It must be in the range of 00. Molecular weight 3000
If the value is smaller than 0, the mechanical properties such as the breaking strength and elongation of the block copolymer itself decrease, and when the composition is used, the strength decreases, which is not preferable. On the other hand, if it exceeds 300,000, processability deteriorates, mixing with a resin having a polar group does not work well, and a composition having sufficient performance cannot be obtained. From this viewpoint, the molecular weight of the block copolymer is more preferably in the range of 80,000 to 250,000.

The addition amount of the block copolymer is 10 to 80.
It is in the range of parts by weight. If the amount is less than 10 parts by weight, sufficient damping performance cannot be imparted to the resin having a polar group. If it exceeds 80 parts by weight, the mechanical strength of the composition cannot be sufficiently improved.

The block copolymer is A (BA)
n and (AB) n are preferably used. Here, A represents a block composed of an aromatic vinyl monomer, B represents a block composed of isoprene, butadiene or a mixture of isoprene and butadiene, and n
Is an integer of 1 or more, preferably 10 or less. Of these, those in the form of ABA are most preferably used.

In the present invention, the block copolymer is obtained by the following various methods.

First, the production of the block copolymer is as follows:
A method of sequentially polymerizing a vinyl aromatic monomer with an alkyl lithium compound as an initiator, followed by isoprene, butadiene or a mixture of isoprene and butadiene,
(B) polymerizing vinyl aromatic monomer followed by isoprene, butadiene or a mixture of isoprene and butadiene,
Coupling this by coupling, or (c) Mixing isoprene, butadiene or isoprene with butadiene using a dilithium compound as an initiator
And then successively polymerizing the vinyl aromatic monomer.

Examples of the alkyl lithium compound include an alkyl compound having an alkyl residue having 1 to 10 carbon atoms, and particularly preferred are methyl lithium, ethyl lithium, pentyl lithium and butyl lithium. As the coupling agent, dichloromethane, dibromomethane, dichloroethane, dibromoethane, dibromobenzene and the like are used. Examples of the dilithium compound naphthalene dilithium, di lithio hexyl benzene. The amount used is a property determined by the molecular weight to be determined, but based on 100 parts by weight of all monomers used for polymerization,
The initiator is generally used in the range of 0.01 to 0.2 part by weight, and when the coupling agent is used, the initiator is used in the range of about 0.04 to 0.8 part by weight.

Isoprene, butadiene or isoprene
In order to make the part consisting of a mixture of butadiene and butadiene have a microstructure with a vinyl bond content of 30% or more, a cocatalyst is required in the polymerization of isoprene, butadiene or a mixture of isoprene and butadiene. Is a Lewis base. Examples of Lewis bases are dimethyl ether,
Ethers such as diethyl ether and tetrahydrofuran; glycol ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether; amine compounds such as triethylamine, N, N, N ', N'-tetramethylethylenediamine (TMEDA) and N-methylmorpholine; Is mentioned. The amount of the Lewis base is used in the range of approximately 0.1 to 1,000 mols per mol of the number of moles of lithium polymerization initiator.

In the polymerization, it is preferable to use a solvent in order to facilitate the control. As the solvent, an organic solvent inert to the polymerization initiator is used. Particularly, the carbon number is 6-1.
2, aliphatic, alicyclic and aromatic hydrocarbons are preferably used. Examples include hexane, heptane, cyclohexane, methylcyclohexane, benzene and the like.

The polymerization is carried out in any of the polymerization methods from 0 to
The reaction is performed at a temperature of 80 ° C. for a period of 0.5 to 50 hours.

The block copolymer is hydrogenated by a known method , if necessary . For the hydrogenation reaction, a method in which hydrogen in a molecular state is reacted with a known hydrogenation catalyst in a state of being dissolved in a hydrogenation catalyst and a solvent inert to the reaction is preferably used.
The catalyst used is Raney nickel or P
Heterogeneous catalysts such as those in which metals such as t, Pd, Ru, Rh, and Ni are supported on a carrier such as carbon, alumina, and diatomaceous earth; or a combination of a transition metal and an alkylaluminum compound or an alkyllithium compound. A Ziegler catalyst or the like is used. The reaction is carried out at a hydrogen pressure of normal pressure to 200 kg / cm ² , and at a reaction temperature of normal temperature to 250 kg / cm ² .
C. and the reaction time is in the range of 0.1 to 100 hours. The block copolymer after the reaction is obtained by coagulating the reaction solution with methanol or the like and then heating or drying under reduced pressure, or by pouring the reaction solution into boiling water and removing the solvent by azeotropic distillation, and then heating or drying under reduced pressure. can get.

The degree of hydrogenation is determined by the required level of the physical properties.
% Or more, preferably 70% or more.

The modified polymer of the component (c) used in the present invention requires that the polymer before modification has an affinity with the block copolymer of the component (b). Examples thereof include a block copolymer composed of at least one block composed of a vinyl aromatic monomer and at least one block composed of a conjugated diene, or a block copolymer composed of a vinyl aromatic monomer such as a hydrogenated product thereof. Olefin polymers such as block copolymers having blocks, ethylene-propylene-diene copolymer (EPDM), and polypropylene are exemplified.

The functional group introduced into the modified polymer of the component (c) used in the present invention is a group having affinity or reactivity with the polar group of the resin having the polar group of the component (a), Specific examples thereof include a carboxyl group or a derivative group thereof, and an epoxy group.

The amount of addition of these functional groups is from 0.02 to 50 mol per mol of the monomer units of the polymer before modification.
Mol% range. When the addition amount is less than 0.02 mol%, the effect of the improvement is small when the composition is used as compared with the case where the modified polymer is not added, and the impact resistance is not particularly improved. On the other hand, if it exceeds 50 mol%, gels and the like are generated, which is not preferable.

The modified polymer containing a carboxyl group or a derivative thereof can be obtained by an addition reaction of an unsaturated carboxylic acid or a derivative thereof. For example, maleic acid, maleic anhydride, fumaric acid, itaconic acid, acrylic acid, crotonic acid, cis-4-cyclohexane-1,2-dicarboxylic acid and their anhydrides, endo-cis-bicyclo (2,2,1 ) -5-Heptene-2,3-dicarboxylic acid and its anhydride, maleimide, etc., with maleic anhydride being particularly preferred.

This addition reaction is carried out in a solution state or a melt state of the polymer before modification and the unsaturated carboxylic acid or its derivative with or without a radical initiator.

The modified polymer containing an epoxy group can be obtained by reacting the polymer before modification with an organic acid peroxide in a solution state.

The amount of the modified polymer is in the range of 2 to 80 parts by weight. If the amount is less than 2 parts by weight, the improvement effect by adding the modified polymer cannot be obtained. On the other hand, when the amount exceeds 80 parts by weight, the composition ratio of the component (b) becomes low, and sufficient vibration damping performance is not exhibited.

Various additives are used in the composition of the present invention to such an extent that its properties are not impaired. For example, 5-
250 parts by weight of carbon black, silica, calcium carbonate, mica, reinforcing agents or fillers such as glass fibers,
And 0.01 to 5 parts by weight of an antioxidant and an ultraviolet absorber coloring agent. In particular, mica is preferably used because it improves vibration damping performance.

Further, other polymers can be blended and used as long as the purpose of the present invention is not impaired. Examples thereof include polystyrene, ABS resin, and polyphenylene ether resin. The blending ratio of these polymers is preferably about 30% by weight or less.

The composition of the present invention is mixed with a kneader, an extruder, an injection molding machine or the like, molded and used.

[0042]

The present invention will be described more specifically with reference to the following examples.

The measured values in the examples were obtained by the following methods.

The molecular weight was determined by GPC.

The microstructure was measured by NMR spectrum,
The content of the 3,4 bond and the 1,2 bond was calculated from the ratio of the peaks of the 3,4 bond and the 1,2 bond at 4.8 ppm and 5.8 ppm.

The hydrogenation ratio was calculated from the ratio of the iodine values of the block copolymer before and after the hydrogenation reaction.

The peak temperature of tan δ was determined by measuring a viscoelastic spectrum using Leo Vibron (manufactured by Orientec). In addition, as an index of the damping performance,
The value of tan δ at 25 ° C. was determined. The larger this value is, the better the vibration damping performance near normal temperature is.

The impact strength was measured using an Izod tester (JIS 71).
Measured and determined according to 10).

Reference Example 1 (Preparation of block copolymer of component (b) of the present invention) In a pressure-resistant reactor substituted with dry nitrogen, cyclohexane as a solvent, n-butyllithium as a polymerization catalyst,
Using TMEDA as a vinylating agent, a styrene monomer, an isoprene monomer, and a styrene monomer were added in this order, followed by polymerization to obtain an ABA type block copolymer (I). Table 1 shows these molecular characteristics.

Reference Example 2 (Preparation of hydrogenated block copolymer of component (b) of the present invention) The ABA type block copolymer (I) obtained in Reference Example 1 was dissolved in cyclohexane with water. Pb-C as cocatalyst
To perform a hydrogenation reaction at a hydrogen pressure of 20 kg / cm ² ,
A hydrogenated block copolymer (II) was obtained. Table 1 shows these molecular characteristics.

[0051]

[Table 1] Reference Example 3 (Preparation of Modified Block Copolymer of Component (c) of the Present Invention) Hydrogenated styrene-isoprene diblock copolymer (SE
P ) 100 parts by weight, 1.5 parts by weight of maleic anhydride, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (manufactured by NOF CORPORATION: Perhexa 25)
B) After uniformly mixing with 1.0 part by weight, an addition reaction of maleic anhydride was performed at a cylinder temperature of 250 ° C. with an extruder to obtain a modified block copolymer (I ) .

The resulting modified block copolymer was dried under reduced pressure to remove unreacted maleic anhydride. Table 2 shows these molecular properties.

[0053]

[0054]

[Table 2] Examples 1 and 2 The hydrogenated block copolymer (II) obtained in Reference Example 2 , polyacetal (manufactured by DuPont: Delrin 500) and polycarbonate (manufactured by Idemitsu Petrochemical Co., Ltd .: Toughlon A2)
200) and the modified block copolymer (I) obtained in Reference Example 3 were kneaded at 200 ° C. for polyacetal and 260 ° C. for polycarbonate by a Brabender plastic coder according to the formulation shown in Table 3 to prepare a composition.
The obtained compositions were press-molded at 210 ° C. and 270 ° C., respectively, and measured for tan δ at 25 ° C. and an impact resistance test (Iz
od).

Comparative Examples 1 to 4 The hydrogenated block copolymer (II) obtained in Reference Example 2 , polyacetal (manufactured by DuPont: Delrin 500) and polycarbonate (manufactured by Idemitsu Petrochemical Co., Ltd.) : Toughlon A2
200) were kneaded and molded in the same manner as in the examples according to the formulations shown in Table 3, and physical properties were measured.

Table 3 shows the measurement results of Examples 1 and 2 and Comparative Examples 1 to 4 . From these results, it is understood that the composition of the present invention has excellent vibration damping performance and excellent impact resistance.

[0057]

[Table 3]

[0058]

According to the present invention, a composition comprising a combination of a resin having a polar group, a block copolymer having a specific molecular structure and a specific modified polymer is provided. It can be used as a material with reduced vibration and noise and improved impact resistance.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-295197 (JP, A) JP-A-4-96969 (JP, A) JP-A-2-88672 (JP, A) JP-A-62-162 149750 (JP, A) JP-A-3-95263 (JP, A) JP-A-3-181552 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 59/00 C08L 69 / 00 C08L 101/02

Claims (1)

(57) [Claims] 1. A (a) a thermoplastic resin 1 having a polar group is a <br/> carbonate bonds in the polyacetal or molecular chain
(B) a block (A) comprising at least one vinyl aromatic monomer and having a number average molecular weight of 2,500 to 40,000
And isoprene, butadiene or a mixture of isoprene and butadiene, having a 3,4 bond and 1,2 bond content of 30% or more and a number average molecular weight of 10,000 to
A block copolymer composed of 200,000 blocks (B) and having a number average molecular weight of 30,000 to 300,000, or a hydrogenated product of 10 to 80 parts by weight, and a polymer having an affinity for the components (c) and (b) The functional group having an affinity or reactivity with the polar group of the component (a) is 0.02 to 2.0 moles per mole of the monomer unit in the molecule.
A resin composition comprising 2 to 80 parts by weight of a modified polymer bonded to 50 mol%.