JP3537537B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic resin composition having excellent rigidity, solvent resistance and impact resistance.

[0002]

2. Description of the Related Art A thermoplastic resin obtained by blending ethylene-propylene rubber (EPR) or a styrene-based elastomer with polypropylene is excellent in mechanical strength, economy, recyclability, etc., so that it is used for interior and exterior parts of automobiles and various industries. It is used in a wide range of fields such as parts.

[0003]

However, these materials do not have a sufficient balance of rigidity, solvent resistance and low-temperature impact resistance, and are sometimes limited in use.

It is an object of the present invention to provide a thermoplastic resin composition having improved rigidity, solvent resistance and impact resistance by improving the balance between them.

[0005]

According to the present invention, the above objects are achieved by (1) 100 parts by weight of polypropylene, (2) 5-1000 parts by weight of a thermoplastic elastomer, and (3)
General formula AB- (A) n (where A is butadiene, the degree of hydrogenation is 70% or more, the 1,2-bond content is 30% or less, and the number average molecular weight is 2500 to 10,000.
B represents isoprene or a mixture of isoprene and butadiene, the degree of hydrogenation of which is 70% or more, and the number average molecular weight of 10,000 to 2,000.
This is solved by providing a resin composition comprising 5 to 1800 parts by weight of a hydrogenated block copolymer represented by the following formula ( 1 ):

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

There is no particular limitation on the polypropylene which is the component (1) used in the present invention. However, when importance is placed on the elastic modulus, homopolypropylene is placed on importance, impact resistance is given on block polypropylene, and transparency is placed on importance. In this case, it is preferable to use random polypropylene. These polypropylenes may be used in combination.

Further, polypropylene modified with an unsaturated carboxylic acid derivative or an anhydride thereof, or polypropylene having a functional group such as a hydroxyl group, a carboxyl group, or an epoxy group introduced at a molecular terminal may be used.

The thermoplastic elastomer of the component (2) used in the present invention is an olefin-based or styrene-based thermoplastic elastomer. Examples of the olefin-based thermoplastic elastomer include ethylene-propylene rubber (EPR), a simple blend of an olefin-based resin and EPR or a blend obtained by dynamic vulcanization, and a modified product thereof with an unsaturated carboxylic acid derivative.
Examples of the styrene-based thermoplastic elastomer include a hydrogenated styrene-butadiene block copolymer, a hydrogenated styrene-isoprene block copolymer, a hydrogenated styrene-butadiene / isoprene block copolymer, and a styrene-isobutylene block copolymer. And modified products thereof with unsaturated carboxylic acid derivatives or anhydrides.

The thermoplastic elastomer is polypropylene 1
It is used in the range of 5 to 1000 parts by weight with respect to 00 parts by weight. If the amount is less than 5 parts by weight, the impact resistance of the resin composition becomes low, which is not preferable. Conversely, if the amount is more than 1000 parts by weight, sufficient solvent resistance cannot be obtained, which is not preferable.

[0011] The polymer block A constituting the hydrogenated block copolymer as the component (3) used in the present invention consists of butadiene, the 1, 2-bond content of 30%
It is as follows. If the 1,2-bond content is more than 30%, sufficient rigidity and strength cannot be obtained when a resin composition is formed, and sufficient solvent resistance cannot be obtained, which is not preferable.

The number average molecular weight of the polymer block A is 250
The range is from 0 to 100,000. Number average molecular weight of 250
If it is less than 0, the performance as a resin composition is reduced. If it exceeds 100,000, the melt viscosity becomes too high, and mixing with the components (1) and (2) does not work well, which is not preferable.

The hydrogenation rate of the polymer block A needs to be 70% or more, more preferably 80% or more. If the degree of hydrogenation is lower than 70%, crystallinity cannot be obtained, sufficient strength as a hydrogenated block copolymer cannot be obtained, and sufficient rigidity, strength, and solvent resistance when a resin composition is used. It is not preferable because the property cannot be obtained.

[0014] ratio in the hydrogenated block copolymer of the polymer block A is preferably in the range of 5 to 95 wt%. If the proportion is less than 5% by weight, the mechanical properties of the hydrogenated block copolymer itself become insufficient, and if it exceeds 95% by weight, sufficient impact resistance cannot be obtained when the resin composition is used. There is.

The polymer block B of the hydrogenated block copolymer is comprised mixing <br/> compound of isoprene or isoprene and butadiene, in this case, the isoprene units 1,2
It is desirable that the total of the bond content, the 3,4-bond content and the 1,2-bond content in the butadiene unit is 5% or more.

When the polymer block B is composed of a mixture of isoprene and butadiene, the mixing ratio is arbitrary and the form is preferably random or tapered. However, the 1,2-bond content in the isoprene unit and 3,3
When the sum of the 4-bond content and the 1,2-bond content in the butadiene unit is 30% or less, the amount of butadiene in the mixture of isoprene and butadiene is preferably 80% or less. When the amount of this butadiene exceeds 80%, the crystallinity becomes high and the rubber elasticity may decrease.

The number average molecular weight of the polymer block B in the hydrogenated block copolymer ranges from 10,000 to 200,000. When the number average molecular weight is less than 10,000,
Sufficient impact resistance can not be obtained, and when it exceeds 200,000 too high melt viscosity of the hydrogenated block copolymer, component (1), go wrong mixing with component (2).

[0018] ratio in the hydrogenated block copolymer of the polymer block B is preferably in the range of 5 to 95 wt%. 5
%, Sufficient impact resistance may not be obtained, and if it is more than 95%, the mechanical strength of the hydrogenated block copolymer may be insufficient.

The hydrogenation rate of the polymer block B needs to be 70% or more, more preferably 80% or more. If the degree of hydrogenation is lower than 70%, sufficient weather resistance and heat resistance cannot be obtained, which is not preferable.

The number average molecular weight of the hydrogenated block copolymer used as the component (3) of the present invention is from 20,000 to 30.
It is preferably in the range of 0000. When the number average molecular weight is less than 20,000, the mechanical properties such as the breaking strength and elongation of the hydrogenated block copolymer itself are reduced, and when the resin composition is used, the strength may be reduced. Further, the number average molecular weight exceeds 300,000, the workability becomes poor, component (1), unsuccessful mixing with component (2),
A resin composition having sufficient performance may not be obtained. From this viewpoint, the molecular weight of the hydrogenated block copolymer is more preferably in the range of 30,000 to 250,000.

The hydrogenated block copolymer is used in the range of 5 to 1800 parts by weight based on 100 parts by weight of polypropylene. If the amount is less than 5 parts by weight, sufficient impact resistance cannot be obtained, which is not preferable. On the other hand, when the amount is more than 1800 parts by weight, the mechanical strength of the resin composition decreases, which is not preferable.

The block form of the hydrogenated block copolymer is A
-B- (A) n ( n represents 1 ), and the hydrogenated block copolymer may be a combination of ABA type and AB type.

The hydrogenation rate of the hydrogenated block copolymer is as follows:
From the viewpoint of heat resistance, it is preferably at least 70%, more preferably at least 80%. On the other hand, if the degree of hydrogenation is smaller than 70%, sufficient solvent resistance may not be obtained when a resin composition is formed.

In the present invention, the hydrogenated block copolymer comprises:
The above and modified hydrogenated block copolymer added was an unsaturated carboxylic acid hydrogenated block copolymer with a peroxide such as kneader or solution reaction using a carboxyl group using a reactive active terminals And a modified hydrogenated block copolymer having an epoxy group, a hydroxyl group and the like introduced at the molecular terminal.

The hydrogenated block copolymer as the component (3) can be obtained by the following various methods.

Firstly, production of the block copolymer, the monomer was polymerized monomer over constituting the polymer block A sequential adding process is polymerized or alkyllithium compounds, as initiator an alkyl lithium compound as an initiator, then performed by a method of obtaining a a-B-a type block copolymer with a coupling agent after the addition of monomers over constituting the polymer block B polymerized. When a coupling agent is used, ABA type and AB type block copolymers can be synthesized simultaneously by controlling the amount of the coupling agent added. Examples of the coupling agent used, dichloromethane, jib <br/> b mode, dichloroethane, diblock mode ethane, diblock
Mode benzene or the like is used.

[0027] Examples of the alkyl lithium compound, although the number of carbon atoms in the alkyl residue include alkyl lithium compound <br/> of 1-10, especially methyl lithium, ethyl lithium, pentyl lithium, butyl lithium preferred. Examples of the dilithium compound include naphthalenedilithium and dilithiohexylbenzene. The amount used is a property determined by the molecular weight of the block copolymer to be obtained, and is generally used in the range of 0.01 to 0.2 part by weight of initiator based on 100 parts by weight of all monomers used for polymerization. .

In the polymerization, it is preferable to use a solvent in order to facilitate the control of the polymerization reaction. As the solvent inert organic solvents are used to open <br/> initiator. In particular, aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons having 6 to 12 carbon atoms are preferably used. Examples include hexane, heptane, cyclohexane, methylcyclohexane, benzene and the like.

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

The block copolymer is hydrogenated by a known method. For the hydrogenation reaction, a method in which a molecular hydrogen is reacted with a known hydrogenation catalyst in a state where the block copolymer is dissolved in a solvent inert to the reaction is preferably used. The catalyst used is Raney nickel or Pt, P
Metals such as d, Ru, Rh, and Ni are converted to carbon, alumina,
Examples include a heterogeneous catalyst supported on a carrier such as diatomaceous earth, a Ziegler-based catalyst comprising a combination of a transition metal, an alkylaluminum compound, an alkyllithium compound, and the like.
The reaction is carried out under a hydrogen pressure of normal pressure to 200 kg / cm ² , a reaction temperature of normal temperature to 250 ° C., and a reaction time of 0.1 to 1 kg.
It is performed in the range of 00 hours.

The hydrogenated block copolymer after the hydrogenation reaction is removed by coagulating the reaction solution with methanol or the like and then heating or drying under reduced pressure, or pouring the reaction solution into boiling water and azeotropically evaporating the solvent. Thereafter, it is obtained by heating or drying under reduced pressure.

The resin composition of the present invention may contain a softener. As such a softener, the above components (1) to
There is no particular limitation as long as it has good compatibility with the component (3), and a mineral oil-based softener generally used as a rubber softener is preferably used. Examples of the mineral oil-based softener include paraffinic, naphthenic, aromatic process oils, oligomers of ethylene-α-olefin, paraffin wax, and liquid paraffin.
The content of the softener is in the range of 0 to 300 parts by weight based on 100 parts by weight of the total of the components (1) to (3) . If the content of the softener exceeds 300 parts by weight with respect to 100 parts by weight of the total weight of the components (1) to (3) , the bleeding of the softener becomes severe, which is not preferable.

The resin composition of the present invention can contain various additives as long as its properties are not impaired.
Examples thereof include carbon black, silica, calcium carbonate, talc, mica, and reinforcing agents or fillers such as glass fibers in an amount of 5 to 250 parts by weight,
Alternatively, an antioxidant, an ultraviolet absorber, a coloring agent, etc.
It can be used in an amount of 1 to 5 parts by weight. In particular, mica is preferably used because it improves vibration damping performance.

[0034]

Further, the resin composition of the present invention can be blended with another polymer as long as the purpose of the present invention is not impaired. Examples thereof include styrene-butadiene block copolymer, styrene-isoprene block copolymer, polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, 1,2- Examples thereof include polybutadiene, polybutene, polyisobutylene, and EPDM. The proportion of these polymers used is preferably about 50% or less with respect to the resin composition of the present invention.

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

The resin composition of the present invention has rigidity, solvent resistance,
Because it is a material with excellent balance of impact resistance at low temperatures, it is used for automotive exterior parts such as bumpers, side moldings, fender liners, automotive interior materials such as console boxes, instrument panels and dashboards, home appliances, OA equipment,
It can be used in a wide range of fields such as various parts and housings of audio equipment, medical materials such as infusion bags, syringes and medical tubes, sports goods, toys, household goods, hoses and films.

[0038]

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 content of 1,2-bonds in isoprene units
And 3,4-bond content and 1,2-
The bond content (vinyl bond amount) was calculated from the NMR spectrum.

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

The solvent resistance test was 5 cm × 5 cm × 1 m
The evaluation was performed by observing the state of the test piece after immersing the press-formed sheet of m in 300 ml of toluene for 48 hours.

The rigidity is determined by the flexural modulus (JIS K730).
1) was evaluated by measuring.

The impact strength was measured using an Izod tester (JIS K
7110) at 25 ° C. and −20 ° C.

Reference Example 1 (Preparation of hydrogenated block copolymer) In a pressure-resistant reactor substituted with dry nitrogen, butadiene, isoprene, and butadiene were used in this order using cyclohexane as a solvent and n-butyllithium as an initiator. It was added and polymerized to obtain an ABA type block copolymer. The obtained block copolymer was subjected to a hydrogenation reaction in cyclohexane using Pd- carbon as a hydrogenation catalyst at a hydrogen pressure of 20 kg / cm ² to obtain a hydrogenated block copolymer (I).
Table 1 shows the molecular characteristics.

Reference Example 2 (Preparation of hydrogenated block copolymer) Polymerization and hydrogenation were carried out in the same manner as in Reference Example 1 except that butadiene, a mixture of isoprene and butadiene (isoprene / butadiene = 5/5) and butadiene were added in this order. Perform the reaction and
A -BA type hydrogenated block copolymer (II) was obtained. Table 1
The molecular characteristics are shown in FIG.

[0048]

[0049]

[0050]

[Table 1]

Examples 1 to 3 The hydrogenated block copolymer (I) obtained in Reference Examples 1 and 2 ,
(II ) and polypropylene, EPR or hydrogenated styrene
The resin composition was prepared by kneading the butadiene block copolymer with the formulation shown in Table 2 at 230 ° C. using a Brabender plastcoder. Each of the obtained resin compositions was press-molded at 230 ° C., a solvent resistance test,
The measurement of the flexural modulus and the impact resistance test (Izod) were performed.

Table 2 shows the measurement results.

Tree By butadiene block copolymer, the EPR and polypropylene kneaded at 230 ° C. by Brabender Plasticorder by the formulations shown in Table 2 - [0053] Comparative Examples 1 and 2 hydrogenated styrene
A resin composition was prepared, and each of the obtained resin compositions was 23
Press molding was performed at 0 ° C., and the same measurement as in the example was performed.

Table 2 also shows the measurement results.

[0055]

[Table 2]

Examples 4 to 6 The hydrogenated block copolymer (I) obtained in Reference Examples 1 and 2 ,
(II ) and polypropylene, EPR or hydrogenated styrene
Table 3 shows butadiene block copolymer and process oil
The resin composition was prepared by kneading at 230 ° C. with a Brabender plastic coder according to the formulation shown in (1).
Each of the obtained resin compositions was press-molded at 230 ° C., and a solvent resistance test, a measurement of a flexural modulus, and an impact test (I
zd).

Table 3 shows the measurement results.

Comparative Examples 3 and 4 Polypropylene, EPR or hydrogenated styrene-butadiene block copolymer and a process oil were mixed at 230 ° C. by a Brabender plastic coder according to the formulation shown in Table 3.
To prepare a resin composition. Got
Each of the resin compositions was press-molded at 230 ° C., and the same measurement as in the examples was performed.

Table 3 also shows the measurement results.

[0060]

[Table 3]

From the comparison of the experimental results in Examples 1 to 6 and Comparative Examples 1 to 4, the resin composition of the present invention is an excellent material having a good balance of rigidity, solvent resistance and low-temperature impact resistance. You can see that.

[0062]

The resin composition of the present invention has a rigidity, solvent resistance and low temperature by blending polypropylene with EPR, hydrogenated styrene thermoplastic elastomer and hydrogenated block copolymer having a specific structure. Improving the balance of impact resistance in automobiles, it can be used in a wide range of fields, including interior and exterior parts of automobiles.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-268174 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 1/00-101/16

Claims (1)

(57) [Claims] (1) 100 parts by weight of polypropylene,
(2) 5 to 1000 parts by weight of a thermoplastic elastomer, and (3) a general formula AB- (A) n (where A is butadiene, the hydrogenation ratio of which is 70% or more; −
When the bond content is 30% or less and the number average molecular weight is 2500 to 1
B represents isoprene or a mixture of isoprene and butadiene, has a hydrogenation ratio of 70% or more, and has a number average molecular weight of 10,000 to 10,000.
Represents 200,000 polymer blocks, and n represents 1.)
A resin composition comprising 5 to 1800 parts by weight of a hydrogenated block copolymer represented by the formula: