JP2002167472A - Hydrogenated rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hydrogenated rubber composition excellent in external appearance, thermal and optical stabilities, flaw resistance, oil resistance and mechanical strength. SOLUTION: The hydrogenated rubber is a homopolymerized rubber, composed of at least one kind of a conjugate diene type monomer, or a random- copolymerized rubber, composed of the conjugated diene type monomer and an aromatic vinyl monomer, wherein a hydrogenated ratio of total double bonds is 50% or more. The hydrogenated rubber composition is crosslinked and composed of the hydrogenated rubber, that is composed of a hydrogenated rubber (A) having the aromatic vinyl monomer of 5 wt.% or below and a hydrogenated rubber (B) having the aromatic vinyl monomer of 5 wt.% or above and 90 wt.% or below, and (C) a thermoplastic resin. Further, this hydrogenated rubber composition is characterized in that the difference of the aromatic vinyl monomer contents between the hydrogenated rubber (B) and the hydrogenated rubber (A) is 5 wt.% or above.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a hydrogenated rubber composition. More specifically, the present invention relates to a hydrogenated rubber composition having excellent appearance, heat / light stability, scratch resistance, oil resistance, and mechanical strength.

[0002]

2. Description of the Related Art A thermoplastic elastomer composition obtained by so-called dynamic crosslinking, in which a radically crosslinkable elastomer and a resin having no radically crosslinkable properties such as PP are crosslinked while being melt-kneaded in an extruder in the presence of a radical initiator, is known. This is a well-known technology, and is widely used for applications such as automobile parts.

[0003] As such a rubber-based composition, an olefin-based elastomer produced from ethylene-propylene-diene rubber (EPDM) (JP-A-8-120127) is used.
Japanese Patent Application Laid-Open No. Hei 9-137001) is known, but is inferior in scratch resistance and is not always satisfied in the market.

On the other hand, as a dynamic cross-linking technique using a saturated rubber, for example, an olefin copolymer rubber is mainly used, a hydrogenated diene rubber is used in an auxiliary manner, and a crystalline α-olefin polymer, an ethylene A dynamically crosslinked elastomer composition containing a polymer and a softening agent (JP-A-9-302156), a polyolefin-based resin, and a random copolymer or block copolymer of a conjugated diene-aromatic vinyl monomer are used as a crosslinking agent. There is known a thermoplastic elastomer composition obtained by melt-mixing in the presence of (JP-A-3-2240).

However, since the above-mentioned composition is not always sufficient in mechanical strength, scratch resistance, appearance and heat / light stability, a rubber composition which can be used practically is required.

[0006]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention provides a rubber composition which does not have the above-mentioned problems, that is, which is excellent in heat / light stability, scratch resistance and mechanical strength. It is intended to provide.

[0007]

Means for Solving the Problems As a result of intensive studies on the improvement of a rubber composition, the present inventors have surprisingly found that a combination of a plurality of specific crosslinkable rubber-based polymers has a thermal
It has been found that light stability, scratch resistance, oil resistance and mechanical strength are dramatically improved.

That is, the present invention relates to a homopolymer rubber of at least one conjugated diene monomer or a random copolymer rubber composed of a conjugated diene monomer and an aromatic vinyl monomer. A hydrogenated rubber having a hydrogenation ratio of 50% or more, in which the amount of the aromatic vinyl monomer is less than 5% by weight and the amount of the hydrogenated rubber (A) is 5% by weight.
Above, a hydrogenated rubber consisting of a hydrogenated rubber (B) of not more than 90% by weight and (C) a thermoplastic resin.
A crosslinked hydrogenated rubber composition, wherein the aromatic vinyl monomer in the hydrogenated rubber (B) and the hydrogenated rubber (A)
It is intended to provide a hydrogenated rubber composition characterized in that the difference between the aromatic vinyl monomers in the composition is 5% by weight or more.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The composition of the present invention is a rubber composition obtained by crosslinking (A) and (B) two kinds of specific crosslinkable rubber-based polymers and (C) a thermoplastic resin.

Here, the hydrogenated rubbers (A) and (B) have 5% of the total double bonds of the unsaturated rubber composed of a polymer having a double bond in a main chain and a side chain and / or a random copolymer.
It is important that 0% or more is hydrogenated. If the hydrogenation rate is less than 50%, the thermal stability and the light stability are reduced.

The chain structure of ethylene after hydrogenation is preferably random, and as an index, it is preferable that the crystallization peak calorie is 100 J / g or less in a differential scanning calorimetry (DSC method). And more preferably 50 J / g or less. Particularly when the hydrogenated rubber is a block copolymer, for example, when it is composed of an aromatic vinyl block unit and a hydrogenated conjugated diene block unit, the crosslinking reaction is suppressed due to the aromatic vinyl block unit, and the obtained The mechanical strength of the elastomer composition is poor. In addition, when a continuous ethylene chain is present in the hydrogenated conjugated diene, the crosslinking reaction proceeds rapidly, and the appearance and mechanical properties of the obtained elastomer composition due to aggregation of the crosslinked rubber occur. The strength is significantly reduced.

It is important that the hydrogenated rubbers (A) and (B) having different structures are present at the same time during the crosslinking reaction. The present inventors have found that the presence of a plurality of hydrogenated rubbers exerts an interaction between the two and dramatically improves heat / light stability, scratch resistance, oil resistance and mechanical strength, and completed the present invention.

Hereinafter, each component of the present invention will be described in detail.

In the present invention, (A) the hydrogenated rubber comprises:
A conjugated diene homopolymer having a double bond in the main chain and a side chain, or a random copolymer of a conjugated diene monomer having an aromatic vinyl monomer content of less than 5% by weight and an aromatic vinyl monomer It is a unified hydrogenated rubber, and for example, olefin-based, methacrylate-based, acrylate-based, unsaturated nitrile-based, and vinyl chloride-based monomers can be added as needed.

(A) The content of the aromatic vinyl monomer in the hydrogenated rubber is preferably less than 5% by weight, more preferably 0 to 3%.
% By weight, most preferably 0% by weight.

The total double bonds in the hydrogenated rubber (A) are 50% or more, preferably 90% or more, more preferably 95% or more hydrogenated, and the remaining double bonds in the main chain are 5% or more. Hereinafter, the residual double bond in the side chain is preferably 5% or less. Specific examples of such a rubber include a rubbery polymer obtained by partially or completely hydrogenating a diene rubber such as polybutadiene, polyisoprene, and polychloroprene, and in particular, hydrogenated butadiene or hydrogenated isoprene. A system rubber is preferred.

In the present invention, (B) the hydrogenated rubber comprises:
A random combination of at least one conjugated diene monomer and an aromatic vinyl monomer having 5 to 90% by weight of an aromatic vinyl monomer having a double bond in a main chain and a side chain. Is a copolymer, if necessary, for example, hydrogenated rubber of a random copolymer containing olefin-based, methacrylate-based, acrylate-based, unsaturated nitrile-based, vinyl chloride-based monomers, etc. is there.

The total double bonds in the hydrogenated rubber (B) are 50% or more, preferably 90% or more, more preferably 95% or more hydrogenated, and the remaining double bonds in the main chain are 5% or more. Hereinafter, the residual double bond in the side chain is preferably 5% or less. As a specific example of such a rubber, poly (styrene-butadiene) is most preferable.

(B) The content of the aromatic vinyl monomer in the hydrogenated rubber is preferably 5 to 90% by weight, more preferably 5 to 90% by weight.
It is 60% by weight, most preferably 10 to 50% by weight.

Such hydrogenated rubbers (A) and (B) are
It is obtained by partially hydrogenating the above rubber by a known hydrogenation method. For example, F. L. Ramp, eta
1, J .; Amer. Chem. Soc. , 83,467
2 (1961), a method for hydrogenation using a triisobutylborane catalyst, Hung Yu Chen, J. Am.
Polym. Sci. Polym. Letter E
d. , 15, 271 (1977), or hydrogenation using an organic cobalt-organoaluminum catalyst or an organic nickel-organoaluminum catalyst described in JP-B-42-8704. Examples of the method include an addition method. Here, a particularly preferred hydrogenation method is described in JP-A-59-133203 and JP-A-60-2 using a catalyst capable of hydrogenation under low-temperature and low-pressure mild conditions.
No. 201147 or contact with hydrogen in an inert organic solvent in the presence of a catalyst comprising a bis (cyclopentadienyl) titanium compound and a hydrocarbon compound having a sodium, potassium, rubidium or cesium atom The method is disclosed in JP-A-62-207303.

The hydrogenated rubbers (A) and (B)
Mooney viscosity (ML) measured at 20-90, 25
5% by weight styrene solution viscosity at 5 ° C. (5% SV)
Preferably, it is in the range of 20-300 centipoise (cps). A particularly preferred range is 25 to 150 cps.

The difference between the aromatic vinyl monomer in the hydrogenated rubber (B) and the aromatic vinyl monomer in the hydrogenated rubber (A) must be at least 5% by weight. If it is less than 5% by weight, the hydrogenated rubbers (A) and (B) are compatible with each other, and the synergistic effect of the present invention is not exhibited.

Further, the control of the crystallization peak calorie, which is an index of the crystallinity of the hydrogenated rubbers (A) and (B), is performed by adding a polar compound such as tetrahydrofuran or controlling the polymerization temperature. Reduction of the heat of crystallization peak is achieved by increasing the amount of polar compound or decreasing the polymerization temperature to increase the 1,2-vinyl bond.

The content of the hydrogenated rubber (B) in the polymer comprising the hydrogenated rubbers (A) and (B) is 1 to 99% by weight.
Is more preferable, more preferably 10 to 99% by weight, and most preferably 20 to 80% by weight.

In the present invention, the thermoplastic resin (C) is not particularly limited as long as it can be uniformly dispersed in the hydrogenated rubbers (A) and (B). For example, polystyrene-based, polyphenylene ether-based, polyolefin-based, polyvinyl chloride-based, polyamide-based, polyester-based, polyphenylene sulfide-based, polycarbonate-based, polymethacrylate-based, or a mixture of two or more of them can be used. . In particular, an olefin resin such as a propylene resin is preferable as the thermoplastic resin.

Specific examples of the propylene resin most preferably used in the present invention include homo isotactic polypropylene, propylene and other α-ethylene such as ethylene, butene-1, pentene-1 and hexene-1. Examples include an isotactic copolymer resin with olefin (including block and random).

In the present invention, among the (C) thermoplastic resins, (C-1) a propylene random copolymer resin alone such as a random copolymer resin of ethylene and propylene, or (C-1) a propylene random copolymer resin. Polymerized resin and (C
-2) A combination with a propylene block copolymer resin or a homopolypropylene resin is preferable. The appearance and mechanical strength are further improved by combining such two types of olefin resins, such as a crosslinked olefin resin and a decomposed olefin resin.

The (C-1) propylene-based random copolymer resin includes, for example, a random copolymer resin of ethylene and propylene. When an ethylene component is present in the polymer main chain, it is crosslinked by a crosslinking reaction. It becomes a point and shows the characteristics of the crosslinked olefin resin.

(C-2) It is preferable that the propylene-based block copolymer resin or the homopolypropylene-based resin contains α-olefin as a main component and does not contain an ethylene unit in the polymer main chain. However, when an ethylene-α-olefin copolymer is present as a dispersed phase, such as a propylene-based block copolymer resin, it exhibits the properties of a decomposable olefin-based resin.

(C) The thermoplastic resin comprises a plurality of (C-1)
A combination of a propylene-based random copolymer resin, (C-2) a propylene-based block copolymer resin or a homo-propylene resin may be used.

(C-1) Among the propylene-based random copolymer resins, the most preferred random copolymer resin with propylene-based α-olefin is a high-pressure method, a slurry method, a gas-phase method, a bulk method, a solution method. Etc.,
As the polymerization catalyst, a Ziegler-Natta catalyst, a single-site, metallocene catalyst is preferable. When a particularly narrow composition distribution and molecular weight distribution are required, a random copolymerization method using a metallocene catalyst is preferable.

A specific method for producing a random copolymer resin is described in EP 0969043 A1 or US Pat.
1, liquid propylene is introduced into a reactor equipped with a stirrer, and then the catalyst is added from a nozzle to the gas or liquid phase. Next, ethylene gas or α-olefin is introduced into the gas phase or liquid phase of the reactor, and the reaction temperature and the reaction pressure are controlled so that propylene is refluxed. The polymerization rate is controlled by the catalyst concentration and the reaction temperature, and the copolymer composition is controlled by the amount of ethylene or α-olefin added.

The melt index of the olefin resin preferably used as the thermoplastic resin (C) in the present invention is 0.1 to 100 g / 10 min (230 ° C., 2.1
(6 kg load) is preferably used. 10
If it exceeds 0 g / 10 min, the heat resistance and mechanical strength of the thermoplastic elastomer composition tend to be insufficient, and if it is less than 0.1 g / 10 min, the fluidity is poor and the moldability deteriorates. There is a tendency.

In the present invention, the thermoplastic resin (C) is used in a composition ratio of 1 to 1000 parts by weight based on 100 parts by weight of the polymer composed of the hydrogenated rubbers (A) and (B). Preferably 5-500 parts by weight, more preferably 10
１００100 parts by weight. If the amount is less than 1 part by weight, the fluidity and processability of the composition tend to decrease, while if it exceeds 1000 parts by weight, the flexibility of the composition tends to decrease.

The hydrogenated rubber composition of the present invention is preferably crosslinked with (D) a crosslinking agent. (D) a crosslinking agent,
It contains (D-1) a crosslinking initiator as an essential component, and optionally contains (D-2) a polyfunctional monomer and (D-3) a monofunctional monomer.

The crosslinking agent (D) is a hydrogenated rubber (A)
And (B) 0.01 to 10 parts by weight per 100 parts by weight,
It is preferably used in an amount of 0.05 to 3 parts by weight. 0.
If the amount is less than 01 parts by weight, the crosslinking tends to be insufficient,
If the amount exceeds 0 parts by weight, the appearance and mechanical strength of the composition tend to decrease.

Here, the (D-1) crosslinking initiator includes a radical initiator such as an organic peroxide and an organic azo compound. As a specific example, 1,1-bis (t-butylperoxide) is used. Oxy) -3,3,5-trimethylcyclohexane,
1,1-bis (t-hexylperoxy) -3,3,5
-Trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-
Butylperoxy) cyclododecane, 1,1-bis (t
-Butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl-4,
Peroxy ketals such as 4-bis (t-butylperoxy) butane and n-butyl-4,4-bis (t-butylperoxy) valerate; di-t-butyl peroxide, dicumyl peroxide, t -Butylcumyl peroxide, α, α′-bis (t-butylperoxy-m
-Isopropyl) benzene, α, α'-bis (t-butylperoxy) diisopropylbenzene, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5 And dialkyl peroxides such as -bis (t-butylperoxy) hexyne-3.

Further, acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide,
3,5,5-trimethylhexanoyl peroxide,
Diacyl peroxides such as benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and m-trioyl peroxide; t-butylperoxyacetate, t-butylperoxyisobutyrate, t
-Butylperoxy-2-ethylhexanoate, t-
Butylperoxylaurate, t-butylperoxybenzoate, di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxymaleate
Peroxyesters such as -butylperoxyisopropyl carbonate and cumylperoxyoctate.

Further, t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide and 1,1
Hydroperoxides such as 1,3,3-tetramethylbutyl peroxide can be exemplified.

Among these compounds, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl -2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 are preferred.

The (D-1) crosslinking initiator is preferably used in an amount of 1 to 80% by weight, more preferably 10 to 50% by weight, in the (D) crosslinking agent component. If it is less than 1% by weight, crosslinking tends to be insufficient, and if it exceeds 80% by weight, mechanical strength tends to decrease.

In the present invention, one of the (D-2) polyfunctional monomers of the crosslinking agent (D) is preferably a radically polymerizable functional group as a functional group, and particularly preferably a vinyl group. The number of the functional groups is 2 or more, but it is effective especially in the case of having three or more functional groups in combination with the monofunctional monomer (D-3). Specific examples include divinylbenzene, triallyl isocyanurate, triallyl cyanurate, diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, ethylene glycol dimethacrylate, Triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, P-quinone dioxime, P, P'-dibenzoylquinone dioxime, phenylmaleimide, allyl methacrylate, N, N'-
m-phenylene bismaleimide, diallyl phthalate,
Tetraallyloxyethane, 1,2-polybutadiene and the like are preferably used. Particularly, triallyl isocyanurate is preferable. These polyfunctional monomers may be used in combination of two or more.

The (D-2) polyfunctional monomer is preferably used in an amount of 1 to 80% by weight, more preferably 10 to 50% by weight, in the crosslinking agent component (D). If it is less than 1% by weight, crosslinking tends to be insufficient, and if it exceeds 80% by weight, mechanical strength tends to decrease.

The above (D-3) used in the present invention
Monofunctional monomers are vinyl monomers added to control the rate of crosslinking reaction, and are preferably radically polymerizable vinyl monomers, such as aromatic vinyl monomers, acrylonitrile, and methacrylonitrile. Unsaturated nitrile monomers, acrylate monomers, methacrylate monomers, acrylate monomers, methacrylate monomers, maleic anhydride monomers, N-substituted maleimide monomers, and the like. be able to.

The above-mentioned (D-3) monofunctional monomer is preferably used in an amount of 1 to 80% by weight, more preferably 10 to 50% by weight, in the crosslinking agent component (D). If it is less than 1% by weight, crosslinking tends to be insufficient, and if it exceeds 80% by weight, mechanical strength tends to decrease.

In the present invention, (E) a softening agent can be blended, if necessary, in order to improve the processability of the hydrogenated rubber composition.

The (E) softening agent is preferably a paraffinic or naphthenic process oil. These are used for adjusting the hardness and flexibility of the composition in an amount of 5 to 500 parts by weight, preferably 10 to 150 parts by weight, based on 100 parts by weight of the hydrogenated rubbers (A) and (B). If the amount is less than 5 parts by weight, flexibility and processability tend to be insufficient, and if it exceeds 500 parts by weight, oil bleeding tends to be remarkable.

In the present invention, a rubbery polymer other than the hydrogenated rubbers (A) and (B) can be blended if necessary. Such a rubbery polymer is, for example, a copolymer of ethylene and an α-olefin containing ethylene and an α-olefin having 3 to 20 carbon atoms, and an α-olefin having 3 to 20 carbon atoms.
-As the olefin, for example, propylene, butene-
1, pentene-1, octene-1 and the like. Such an ethylene / α-olefin copolymer is preferably produced using a known metallocene catalyst.

In the present invention, the rubbery polymers other than the hydrogenated rubbers (A) and (B) which can be compounded as required include:
A polystyrene-based thermoplastic elastomer is preferable, and examples thereof include a block copolymer composed of an aromatic vinyl unit and a conjugated diene unit, and a block copolymer in which the conjugated diene unit is partially hydrogenated or epoxy-modified.

The aromatic vinyl monomer constituting the block copolymer is, for example, styrene, α-methylstyrene, paramethylstyrene, p-chlorostyrene, p-bromostyrene, 2,4,5-tribromobenzene. Styrene is the most preferable, and styrene is most preferable. However, other aromatic vinyl monomers described above may be copolymerized mainly with styrene.

The conjugated diene monomer constituting the block copolymer includes 1,3-butadiene, isoprene and the like.

In the block structure of the block copolymer, a polymer block composed of an aromatic vinyl unit is represented by S, and a polymer block composed of a conjugated diene and / or a partially hydrogenated unit thereof is represented by B. When displaying with,
SB, S (BS) n (where n is an integer of 1 to 3), S
(BSB) n, where n is an integer of 1 to 2
A block copolymer or (SB) nX (where n is 3 to 6)
Integer. X is a residue of a coupling agent such as silicon tetrachloride, tin tetrachloride, and a polyepoxy compound. ), And is preferably a star-shaped block copolymer having a portion B as a bonding center. Above all, type 2 of SB, type 3 of SBS,
SBSB type 4 linear block copolymers are preferred.

Further, the composition of the present invention can contain an inorganic filler and a plasticizer to such an extent that its characteristics are not impaired. Examples of the inorganic filler used here include calcium carbonate, magnesium carbonate, silica, carbon black, glass fiber, titanium oxide, clay, mica, talc, magnesium hydroxide, and aluminum hydroxide. As the plasticizer, for example, polyethylene glycol, dioctyl phthalate (DO)
And phthalic acid esters such as P). Also, other additives such as organic / inorganic pigments, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, silicone oils, antiblocking agents, foaming agents, antistatic agents, antibacterial agents, etc. Are also preferably used.

For the production of the composition of the present invention, general methods such as a Banbury mixer, a kneader, a single-screw extruder, and a twin-screw extruder used in the production of ordinary resin compositions and elastomer compositions are employed. It is possible to In particular, a twin-screw extruder is preferably used to achieve dynamic crosslinking efficiently. The twin-screw extruder uniformly and finely disperses the hydrogenated rubbers (A) and (B) and further adds other components to cause a crosslinking reaction, thereby continuously producing the composition of the present invention. More suitable to do.

The composition of the present invention is preferably used as a specific example.
It can be manufactured through the following processing steps.
That is, the hydrogenated rubbers (A), (B) and (C) are mixed well with the thermoplastic resin, and then charged into a hopper of an extruder. The crosslinking agent (D) may be added together with the hydrogenated rubbers (A), (B) and (C) thermoplastic resin from the beginning, or may be added in the middle of the extruder. Further, (E) the softening agent may be added from the middle of the extruder, or may be added separately at the beginning and during the middle. Hydrogenated rubber (A), (B)
And (C) a part of the thermoplastic resin may be added in the middle of the extruder. When heated and melted and kneaded in an extruder, the hydrogenated rubbers (A) and (B) undergo a cross-linking reaction with the (D) cross-linking agent, and (E) melt-kneading is performed by adding a softening agent and the like. After sufficient crosslinking reaction and kneading and dispersion are performed, the mixture is taken out of the extruder to obtain pellets of the composition of the present invention.

A particularly preferred melt extrusion method is to have a length L in the die direction with respect to the raw material addition portion,
This is the case where a twin-screw extruder with / D of 5 to 100 (where D is the barrel diameter) is used. The twin-screw extruder has a plurality of supply portions of a main feed portion and a side feed portion having different distances from a tip portion thereof, and between a plurality of the supply portions and between the tip portion and the tip portion. It is preferable that a kneading part is provided between the supply part and a kneading part close to the supply part, and the length of the kneading part is 3D to 10D, respectively.

One of the twin-screw extruders of the production apparatus used in the present invention may be a twin-screw co-rotating extruder or a twin-screw different-direction rotating extruder. In addition, regarding the screw engagement, non-engagement type, partial meshing type,
There is a complete meshing type, and any type may be used. In order to obtain a uniform resin at a low temperature by applying a low shearing force, a different direction rotation / partial engagement screw is preferable. When slightly large kneading is required, a co-rotating / completely meshing screw is preferable. When even greater kneading is required, a co-rotating and fully meshing screw is preferred.

In the present invention, the hydrogenated rubbers (A), (B) and (C) are particularly used for improving the appearance and the mechanical strength.
The morphology of the composition comprising the thermoplastic resin is also important, and it is necessary that the hydrogenated rubber (A) and the component (B) exist as independent particles, and that the thermoplastic resin (C) be a continuous phase, For that purpose, for example, it is important to suppress the crosslinking speed under a high shear force. Specifically, the amount of (D-1) a crosslinking initiator or a crosslinking aid is reduced,
And it is achieved by performing the reaction at a temperature as low as possible for as long as possible, which is higher than the decomposition temperature of the crosslinking initiator (D-1). It can also be achieved by using a combination of a (D-2) polyfunctional monomer and a (D-3) monofunctional monomer as a crosslinking aid.
(D-1) Excessive addition of a crosslinking initiator or a crosslinking aid, or (D-1) a crosslinking initiator or a crosslinking aid having excessively high activity,
Or high-temperature reaction conditions, aggregation of the rubbery polymer occurs,
Does not satisfy the requirements of the present invention. Then, (D-1) a crosslinking initiator and a crosslinking aid are blended into the hydrogenated rubbers (A) and (B) while absorbing a small amount (E) of the softening agent in advance into the hydrogenated rubbers (A) and (B). By doing so, since the crosslinking reaction proceeds gently, uniform particles can be generated with small particles.

As a production method for achieving an excellent appearance and an improvement in mechanical strength, it is more preferable to satisfy the following kneading degree. ^{M = (π 2/2)} (L / D) D 3 (N / Q) 10 × 10 6 ≦ M ≦ 1000 × 10 6 where, L: die direction of extrusion PIC material added section as a base point (mm), D: extruder barrel inner diameter (mm), Q: discharge rate (kg / h), N: screw rotation speed (rpm)

When M is less than 10 × 10 ⁶ , the rubber particles tend to enlarge and agglomerate, so that the appearance tends to deteriorate.
Exceeds 1000 × 10 ⁶ , the mechanical strength tends to decrease due to excessive shearing force.

In order to achieve better appearance and mechanical strength, it is preferable that the following relational expression is satisfied. That is, first, melt-kneading is performed at a melting temperature T ₂ (° C.), and then melt-kneading is performed at a melting temperature T ₃ (° C.). 0.1 L to 0.5 from the addition port
The extruder zone having a length of L is first melt-kneaded at the melting temperature T ₂ (° C.), and then the extruder zone is melted at the melting temperature T ₂ (° C.).
Melt and knead at ₃ (℃).

Here, it is particularly preferable that T ₁ is 150 to 250 ° C., and T ₂ or T _{3 in} each zone of the melt extruder may be a uniform temperature or may have a temperature gradient. Is also good. T ₁ : (D) 1 minute half-life temperature (° C.) of the crosslinking agent T ₁ -100 <T ₂ <T ₁ +40 T ₂ +1 <T ₃ <T ₂ +200

The rubber composition thus obtained can be used to produce various molded articles by any molding method. Injection molding, extrusion molding, compression molding, blow molding, calender molding, foam molding and the like are preferably used.

[0065]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In these examples and comparative examples, the test methods used for evaluating various physical properties are as follows.

1. Analysis of hydrogenated rubber 1) Hydrogenation rate (%) It was measured by NMR according to the following procedure.

First, the polybutadiene rubber before hydrogenation was dissolved in deuterated chloroform, and FT-NMR (270 Meg.,
Proton (= CH ₂ ) by 1,2-vinyl having a chemical shift of 4.7 to 5.2 ppm (referred to as signal C0) and a chemical shift of 5.2 to 5.8 ppm (referred to as signal D0) at JEOL. ) Was calculated by the following equation from the integrated intensity of the vinyl proton (= CH-). (V) = [0.5C0 / ｛0.5C0 + 0.5 (D0−
0.5C0)｝] × 100

Next, the hydrogenated rubber after the partial hydrogenation was dissolved in deuterated chloroform, and similarly, by FT-NMR, the hydrogenated rubber having a chemical shift of 0.6 to 1.0 ppm (signal A1) was used. , The methyl group proton due to the 2 bond (−
CH ₃ ), protons by non-hydrogenated 1,2-vinyl with a chemical shift of 4.7-5.2 ppm (referred to as signal C1) (= CH ₂ ), chemical shifts 5.2-5.8.
It was calculated from the integrated intensity of a non-hydrogenated vinyl proton (= CH-) in ppm (referred to as signal D1) by the following equation.

First, p = 0.5C0 / (0.5C1 + A
1/3), A11 = pA1, C11 = pC1, D11 =
Let pD1 be the hydrogenation rate of the 1,2-vinyl bond (B) (B) = [(A11 / 3) / ｛A11 / 3 + C11 /
2｝] × 100 Hydrogenation rate of 1,4-double bond (C) (C) = [｛0.5 (D0−0.5C0) −0.5 (D
11-0.5C11)｝ / 0.5 (D0-0.5C
0)] × 100 Hydrogenation rate of whole butadiene part (A) (A) = (V) × (B) / 100 + [100− (V)]
× (C) × 100

2) Microstructure The symbols defined above are described below. 1,2-vinyl bond before hydrogenation = (V) × (B) / 1
00 (%) 1,4 bonds before hydrogenation = {100- (V)} × (C)
/ 100 (%) 1,2-vinyl bond after hydrogenation = (V) × ｛100−
(B)｝ / 100 (%) 1,4-bond after hydrogenation = {100- (V)} × ｛1
00- (B)｝ / 100 (%)

2. Crystallization temperature, crystallization peak calorie Measured by differential scanning calorimetry (DSC method). Specifically, Mac Science (MAK SC)
Using a thermal analyzer system WS002 manufactured by IENCE), a 10 mg sample was heated at a rate of 10 ° C./minute from room temperature under a nitrogen stream, and after reaching 100 ° C., immediately cooled to −100 ° C. at a rate of 10 ° C./minute. In the present invention, the crystallization temperature and the crystallization peak calorie were determined from the crystallization peak detected at this stage.

Here, the crystallization temperature is the peak top temperature (° C.), and the crystallization peak calorie (J / g) is calculated from the peak area surrounded by the curve showing the change in calorific value changed from the baseline. did. The curve includes either a broad curve or a sharp curve. In addition, the peak top temperature means a point where a straight line is drawn in parallel with the base line and a tangent to a curve showing a change in calorific value.

3. Light stability US ATLAS Electric as a light stability tester
c DevicesCo. ATLAS CI35W
JIS K71 using a Weatherometer
02. Irradiation conditions were: internal temperature of the tester, 55 ° C., humidity 55%, no rain, xenon light (wavelength 340 nm, energy 0.30 W / m ² ) 3
The irradiation was performed for 00 hours. Using SM Color Computer Model SM-3 manufactured by Suga Test Instruments Co., Ltd. a. b. The color difference ΔE of the molded body before and after the test was determined by the method, and the color tone change was evaluated. The smaller the change in color tone, the higher the light stability (light resistance).

4. Thermal stability (thermogravimetric balance test: TGA
Method) Using a Shimadzu thermal analyzer DT-40 manufactured by Shimadzu Corporation, it was kept at 200 ° C. for 1 hour under a nitrogen stream, and the retention (%) based on the initial weight was used as a measure of thermal stability.

5. Appearance Appearance was evaluated from the sheet skin according to the following criteria. ◎ Very good. ○ Good. △ Good, but slightly rough. × Overall rough, no gloss.

6. Tensile breaking strength [MPa] Evaluated at 23 ° C. according to JIS K6251.

7. Scratch resistance The tip is a rectangle with a length of 10 mm and a width of 1 mm, and the weight is 30
The sheet was scratched by dropping a 0 g wedge from a height of 5 cm onto the sheet, and the sheet was visually evaluated according to the following criteria. ◎ Very good. ○ Good. △ Good, but scratches are noticeable. × The scratch is remarkable.

8. Oil resistance Weight W of a 2 mm thick composition sheet in advance₀Measure
After that, the composition sheet was placed in liquid paraffin at 80 ° C. for 2 hours.
After standing for 0 hours, the weight of the composition sheet (W ₁)
And calculate the weight change rate as follows. Where the number
The smaller the value, the better the oil resistance. Weight change rate = (W₁-W₀) / W₀× 100 (%)

The following components were used in Examples and Comparative Examples.

(A) Production of Hydrogenated Rubber A butadiene / n-hexane solution (butadiene concentration: 20% by weight) was used at a rate of 20 liter / hr using an autoclave with a stirrer and a jacket having an internal volume of 10 liters as a reactor. , N-butyllithium / n-hexane solution (concentration: 5% by weight) was introduced at 70 mitter / hr,
Continuous polymerization of butadiene was carried out at a polymerization temperature of 110 ° C.
The activated polymer obtained was deactivated with methanol, and 8 liters of the polymer solution was transferred to another 10 liter reactor equipped with a stirrer and a jacket, and di-p- was added as a hydrogenation catalyst at a temperature of 60 ° C. 250 milliliters of tolylbis (1-cyclopentadienyl) titanium / cyclohexane solution (concentration: 1 milliliter / liter) and 50 milliliters of n-butyllithium solution (concentration: 5 milliliter / liter)
Milliliter at 0 ° C., 2.0 × 10 ⁵ Pa (2 kg
/ Cm ² ), and reacted at a hydrogen partial pressure of 2.9 × 10 ⁵ Pa (3 kg / cm ² ) for 30 minutes. To the obtained hydrogenated polymer solution, 2,6-ditert-butylhydroxytoluene as an antioxidant was added in an amount of 0.5 part per polymer to remove the solvent.
At this time, the butadiene polymer was hydrogenated by changing the hydrogenation reaction conditions (hydrogenation pressure, hydrogenation temperature, time and amount of catalyst) to obtain a hydrogenated polymer. The results are shown in Tables 1 and 2.

The calorific value of the crystallization peak is controlled by adding the polar compound tetrahydrofuran (THF) or controlling the polymerization temperature. The reduction in the heat of crystallization peak is achieved by increasing the amount of the polar compound or lowering the polymerization temperature.

Then, the hydrogenated styrene-butadiene copolymer can be obtained by further adding styrene and conducting polymerization in the same manner as described above. The results are shown in Tables 1 and 2.

(B) Olefin-based resin Polypropylene: isotactic polypropylene (referred to as PP) manufactured by Nippon Polychem Co., Ltd.

(C) Crosslinking agent 1) Crosslinking initiator (D-1) 2,5-dimethyl-2,5-bis (t-manufactured by NOF Corporation)
Butylperoxy) hexane (trade name Perhexa 25)
B) (referred to as POX-1) 2) Crosslinking initiator (D-1) 2,5-dimethyl-2,5-bis (t-manufactured by NOF Corporation)
(Butyl peroxy) hexine-3 (trade name perhexin 25B) (referred to as POX-2) 3) Polyfunctional monomer (D-2) manufactured by Wako Pure Chemical Industries, Ltd., divinylbenzene (referred to as DVB) 4) Multi Functional monomer (D-2) Triallyl isocyanurate (TA) manufactured by Nippon Kasei Co., Ltd.
5) Multifunctional monomer (D-2) N, N'-m phenylenebismaleimide (PMI) manufactured by Ouchi Shinko Chemical Co., Ltd. 6) Monofunctional monomer (D-3) ) Methyl methacrylate (MMA) manufactured by Asahi Kasei Kogyo Co., Ltd.

(D) Paraffin oil Diana Process Oil PW-3 manufactured by Idemitsu Kosan Co., Ltd.
80 (referred to as MO).

<Examples 1 to 24, Comparative Examples 1 to 8>
Using (A), (B) and (C) described in (2), (A) + (B) /
(C) / POX-1 / TAIC / MO (= 100
((A) / (B) are shown in Tables 1 and 2) /80/0.3/
0.6 / 30 weight ratio), a twin screw extruder (40 mmφ, L / D =
47) under the following conditions. As the screw, a double screw having a kneading portion before and after the injection port was used.

(Extrusion conditions) 1) Melt extrusion temperature constant at 220 ° C. 2) Discharge rate Q = 12 kg / h 3) Extruder barrel inner diameter D = 25 mm 4) L / D when extruder length is L (mm) = 47 5) Screw rotation speed N = 280 rpm

A 2 mm thick sheet was prepared from the composition thus obtained at 200 ° C. using a T-die extruder, and various evaluations were made. The results are shown in Tables 1 and 2.

[0089]

[Table 1]

[0090]

[Table 2]

According to Tables 1 and 2, the use of two kinds of hydrogenated rubbers (A) and (B) satisfying the requirements of the present invention is excellent in heat / light stability, scratch resistance, and mechanical strength. It can be seen that a hydrogenated rubber composition can be obtained.

Also, hydrogenated rubbers (A) having different structures
It can be seen that when (B) and (B) are present at the same time during the crosslinking reaction, heat and light stability, scratch resistance, oil resistance and mechanical strength are dramatically improved.

<Examples 25 to 34> In Example 4,
POX-1 and TAIC are shown in Table 3 as (D-1) to (D-3).
And (C) was changed to 60 parts by weight, and further melt-kneaded at a melting temperature T ₂ (° C.) and then melt-kneaded at a melting temperature T ₃ (° C.) according to the following definition. The same experiment was repeated. Table 3 shows the results. When (D-2) and (D-3) were used together, both were used in equal amounts.

[0094]

[Table 3]

According to Table 3, it can be seen that the production under the following melting conditions improves the tensile strength at break, the appearance and the scratch resistance. T ₁ : 1 minute half-life temperature (° C.) of (D-1) T ₁ -100 <T ₂ <T ₁ +40 T ₂ +1 <T ₃ <T ₂ +200

[0096]

The hydrogenated rubber composition of the present invention has excellent appearance, heat and light stability, scratch resistance, oil resistance and mechanical strength.

The composition of the present invention can be used for automobile parts, automobile interior materials, airbag covers, mechanical parts, electric parts, cables, hoses, belts, toys, miscellaneous goods, daily necessities, building materials,
It can be widely used for applications such as sheets and films, and plays a large role in the industrial world.

Continued on the front page F term (reference) 4J002 AC11W AE044 BB12Y BB14Y BB15Y BC02Y BG05Y BP01W BP01X BP02Y CG00Y CH07Y CN01Y EA046 EH076 EK016 EK036 EK046 EK056 EU196 FD010 FD024 FD027 FD146

Claims (4)

[Claims] 1. The hydrogenation rate of all double bonds of a homopolymer rubber of at least one conjugated diene monomer or a random copolymer rubber of a conjugated diene monomer and an aromatic vinyl monomer Is a hydrogenated rubber having 50% or more, and a hydrogenated rubber (A) containing less than 5% by weight of an aromatic vinyl monomer and 5% by weight or more of an aromatic vinyl monomer.
A cross-linked hydrogenated rubber composition comprising a hydrogenated rubber (B) having a content of not more than 10% by weight and a thermoplastic resin (C), and a fragrance in the hydrogenated rubber (B). A hydrogenated rubber composition, wherein the difference between the aromatic vinyl monomer and the aromatic vinyl monomer in the hydrogenated rubber (A) is 5% by weight or more. 2. In a differential scanning calorimetry (DSC method), the hydrogenation rubbers (A) and (B) have a crystallization peak calorie of 1
The hydrogenated rubber composition according to claim 1, wherein the composition is not more than 00 J / g. 3. It is required that 90% or more of the total double bonds of the unsaturated rubber of the hydrogenated rubbers (A) and (B) are hydrogenated, or that the residual double bond of the side chain is 5% or less. The hydrogenated rubber composition according to claim 1 or 2, wherein 4. The method according to claim 1, wherein the thermoplastic resin (C) is an olefin resin, and (D) is partially or completely crosslinked with a crosslinking agent, and further comprises (E) a softening agent. 4. The hydrogenated rubber composition according to any one of items 1 to 3.