JP2001146538A - Impact-resistant thermoplastic polystyrene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly weather-resistant, highly impact-resistant thermoplastic polystyrene resin composition reinforced by a partially or completely crosslinked unsaturated rubber polymer. SOLUTION: This impact-resistant thermoplastic polystyrene resin composition comprises at least (A) from 60 to 99 pts.wt. polystyrene resin, (B) from 1 to 40 pts.wt. partially or completely crosslined unsaturated rubber polymer and (C)<50 pts.wt. compatibilizer against 100 pts.wt. total of components (A) and (B).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a polystyrene-based thermoplastic resin composition reinforced with a partially or completely crosslinked saturated rubbery polymer. More specifically, the present invention relates to a high weather and high impact styrene thermoplastic resin composition reinforced with a partially or completely crosslinked saturated rubber-like polymer.

[0002]

2. Description of the Related Art Polystyrene resins are widely used in home electric appliance materials, food container / packaging materials, information equipment materials, and the like. When used in these applications, polystyrene itself is hard and brittle, so it is difficult to use high-impact polystyrene (HIP).
S) is also widely used.

[0003] This high-impact polystyrene is generally prepared by dissolving polybutadiene in a styrene monomer, and then dispersing the solution in water to carry out suspension polymerization in the presence of a polymerization initiator. Alternatively, it is produced by directly bulk polymerization in the presence of a polymerization initiator or diluting the solution with a solution to carry out solution polymerization. The rubber layer in the impact polystyrene must be cross-linked and have a styrene monomer grafted thereon. The reason for this is that if not cross-linked, it will be deformed in the flow direction during molding, resulting in directionality in impact resistance, which is not preferable.
Also, if the styrene monomer is not grafted, there is no interfacial adhesion between the polystyrene and the rubber layer, and no impact resistance is obtained. In the method for producing impact-resistant polystyrene, when styrene is polymerized in the presence of an initiator, rubber crosslinking and graft reaction of a styrene monomer onto the rubber are caused in one step. The rubber that can be used in this case is a rubber capable of causing crosslinking and grafting at an initiator concentration at which the styrene monomer is polymerized at a constant rate, that is, easily crosslinked with a double bond in the molecule like polybutadiene. Limited to rubber. For example, when a saturated rubber having no double bond, such as EPR (random copolymer of ethylene and propylene), is used as a rubber component, grafting occurs, but the level of crosslinking required for substantial increase in strength can be obtained. Can not.
On the other hand, a rubber having a double bond, as is generally well known, has poor mechanical strength due to a decrease in mechanical strength due to a decrease in molecular weight when used in a place with high light illuminance, for example, outdoors. Therefore, the impact-resistant polystyrene currently marketed has a serious problem that it cannot be used depending on the environment, and cannot be used for a wide range of applications at present. There is a demand for the development of impact-resistant polystyrene that uses a saturated rubber having no double bonds and a reinforcing agent that is excellent in weather resistance.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide an impact-resistant polystyrene having excellent weather resistance in view of the above situation.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, unlike the usual method for producing high-impact polystyrene, for example, a high-density polystyrene was extruded in an extruder. By kneading a saturated rubber-like polymer, a polystyrene-based resin and, if necessary, a compatibilizer in the presence of a radical initiator and a crosslinking aid, an impact-resistant polystyrene-based resin having a crosslinked saturated rubber as a reinforcing agent And found that the present invention was completed.

That is, the present invention relates to (A) a polystyrene resin: 60 to 99 parts by weight, (B) a partially or completely crosslinked saturated rubbery polymer: 1 to 40 parts by weight, and (C) a phase. Solubilizer: relates to an impact-resistant polystyrene-based thermoplastic resin composition comprising less than 50 parts by weight per 100 parts by weight of the components (A) and (B).

Hereinafter, the present invention will be described in detail. First, each component of the present invention will be described in detail. The polystyrene resin as the component (A) of the thermoplastic resin composition of the present invention is basically a polymer of a styrene monomer, that is, a copolymer of polystyrene or a styrene monomer and another monomer. It is a polymer. Examples of the copolymerizable monomer include styrene-based monomers such as α-methylstyrene, p-chlorostyrene, p-bromostyrene, and 2,4,5-tribromostyrene, and acrylonitrile and methacrylonitrile. Unsaturated nitrile monomers, acrylate monomers such as methyl acrylate and butyl acrylate, methacrylate monomers such as methyl methacrylate and ethyl methacrylate, and acids such as maleic anhydride and itaconic anhydride Examples thereof include anhydride monomers, maleimide monomers such as maleimide, N-methylmaleimide and N-phenylmaleimide, and organic acid monomers such as acrylic acid and methacrylic acid. Of these, polystyrene is inexpensive and most preferred. The temperature of the polystyrene resin used was 200 ° C., 5 ° C.
Melt flow rate (MFR) measured under kg load
Is preferably in the range of 0.1 to 50 g / 10 minutes.

As the component (A), a polystyrene-based resin is used as a main component. In addition, if a thermoplastic resin compatible with or evenly dispersible with the polystyrene-based resin is used, the thermoplastic resin is used by coexisting with the polystyrene-based resin. can do.
For example, polyphenylene ether-based, polyvinyl chloride-based, polyamide-based, polyester-based, polyphenylene sulfide-based, polycarbonate-based, and polymethacrylate-based resins can be used alone or in combination of two or more. Among these, a polyphenylene ether-based resin is particularly preferred. When a polyphenylene ether-based resin is present, heat resistance or flame retardancy can be imparted.

Next, the partially or completely crosslinked saturated rubbery polymer as the component (B) will be described. Examples of the saturated rubbery polymer of the present invention include partially or completely crosslinked elastomers of polymers such as styrene, olefin, ester, urethane and vinyl chloride. Among them, styrene-based elastomers and olefin-based elastomers are preferred in terms of characteristics and price. Among them, polyolefin-based elastomers are particularly preferable because of their excellent crosslinkability.

Examples of the styrene-based elastomer include a block polymer or a random polymer composed of an aromatic vinyl unit and a conjugated diene unit, in which a double bond of a conjugated diene component is hydrogenated.
Specifically, the block polymer is composed of at least one polymer block mainly composed of a vinyl aromatic compound (S) and at least one polymer block mainly composed of a hydrogenated conjugated diene. (B), whose structure is, for example, SB, SBS, BSBS, (SB
-) NSi or the like. Examples of the conjugated diene include butadiene and isoprene. When the styrene elastomer is a hydrogenated aromatic vinyl / conjugated diene block or a random copolymer, it is not necessary that the double bond be 100% hydrogenated. It is at least 50% or more, preferably 70% or more, and more preferably 90% or more. By hydrogenation, 10
Even if it is not 0%, the weather resistance is greatly improved. The saturated rubbery polymer of the present invention is a styrene-based elastomer, particularly a hydrogenated aromatic vinyl / conjugated diene block or a random copolymer. Defined as union.

Examples of the olefin-based elastomer include a copolymer of ethylene and an α-olefin or a hydrogenated conjugated diene polymer resulting in a polyolefin.

The ethylene / α-olefin copolymer elastomer is described in detail below.
The ethylene / α-olefin copolymer mainly composed of α-olefin is preferred. Examples of the α-olefin having 3 to 20 carbon atoms include propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, nonene-1, and decene-1. ,
Undecene-1, dodecene-1 and the like. These α-olefins may be used alone or in combination of two or more. Further, a copolymer component may be included as the third component. Examples of the copolymerization component of the third component include conjugated dienes such as 1,3-butadiene and isoprene, and non-conjugated dienes such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, and ethylidene norbornene.

These ethylene / α-olefin copolymer elastomers (eg, EPDM) obtained by copolymerizing a conjugated diene and a non-conjugated diene are compared with polybutadiene.
Since there are few diene components in the molecule, it has excellent weather resistance. The saturated rubbery polymer which is the component (B) in the present invention comprises:
When it is an ethylene / α-olefin copolymer elastomer obtained by copolymerizing a conjugated diene or a non-conjugated diene, the content of the conjugated diene or the non-conjugated diene in the copolymer is at least 50% by weight or less, preferably Is 3
0% by weight or less, more preferably 10% by weight or less.
When the saturated rubbery polymer of the present invention is an ethylene / α-olefin copolymer elastomer obtained by copolymerizing a conjugated diene or a non-conjugated diene, the content of the conjugated diene or the non-conjugated diene is at least 50%. weight%
It is defined as the following rubbery polymer.

As described above, the olefin-based elastomer also includes an ethylene / α-olefin-based copolymer obtained by copolymerizing a conjugated diene or a non-conjugated diene. However, an ethylene / α-olefin copolymer elastomer containing no conjugated diene or non-conjugated diene has excellent weather resistance and is more preferable. Among them, the ethylene / octene-1 copolymer elastomer is most preferable because it can be easily crosslinked.

The ethylene / α-olefin copolymer elastomer suitably used as the component (B) is preferably produced using a metallocene catalyst.

In general, a metallocene-based catalyst is composed of a cyclopentadienyl derivative of a Group IV metal such as titanium or zirconium and a co-catalyst, and is not only highly active as a polymerization catalyst but also has a higher activity than a Ziegler-based catalyst. The molecular weight distribution of the resulting polymer is narrow, and the distribution of the comonomer α-olefin having 3 to 20 carbon atoms in the co-weight is uniform.

For this reason, the polymer obtained with the metallocene-based catalyst has a more uniform cross-linking and exhibits excellent rubber elasticity.

The ethylene / α-olefin copolymer elastomer which is the component (B) preferably used in the present invention preferably has a α-olefin copolymerization ratio of 1 to 60% by weight, more preferably Is from 10 to 50% by weight, most preferably from 20 to 45% by weight. If the copolymerization ratio of the α-olefin exceeds 50% by weight, the molded article obtained from the composition of the present invention is unfavorably greatly reduced in tensile strength and the like. On the other hand, if it is less than 1% by weight, the effect of improving the mechanical strength of the molded article obtained from the composition of the present invention is not obtained, which is not preferable.

The density of the ethylene / α-olefin copolymer elastomer is 0.800 to 0.900 g / cm ³ ,
It is more preferably in the range of 0.850 to 0.900 g / cm ³ . By using a rubber-like polymer having a density in this range, a molded article having excellent impact resistance can be obtained.

The ethylene / α-olefin copolymer elastomer which is the component (B) preferably used in the present invention preferably has a long-chain branch. The presence of the long-chain branch enables the density to be lower than the ratio (% by weight) of the copolymerized α-olefin without lowering the mechanical strength. hardness,
A high-strength rubbery polymer can be obtained. The ethylene / α-olefin copolymer elastomer having a long-chain branch is described in US Pat. No. 5,278,272.

The ethylene / α-olefin copolymer elastomer preferably has a DSC melting point peak at room temperature or higher. When it has a melting point peak, its form is stable in the temperature range below the melting point, and it has excellent handling properties.
There is little stickiness.

The ethylene / α-olefin copolymer elastomer preferably used in the present invention has a melt index of 0.01 to 100 g / 10 minutes (at 190 ° C.,
2.016 kg) is preferably used, and more preferably 0.2 to 20 g / 10 min. 1
If it exceeds 00 g / 10 minutes, the crosslinkability of the rubbery polymer is insufficient, and if it is less than 0.01 / 10 minutes, the flowability of the composition is poor and the processability is undesirably reduced.

The olefin-based elastomer of the present invention also includes a hydrogenated conjugated diene polymer which results in an olefin-based elastomer. The hydrogenated conjugated diene has a double bond having a hydrogen content of at least 50% or more. Rubber-like polymer.

The saturated rubbery polymer which is the component (B) of the composition of the present invention may be used as a mixture of a plurality of types. In such a case, it is possible to further improve the workability.

The rubbery polymer as the component (B) needs to be partially or completely crosslinked. Molded articles obtained from the styrene-based thermoplastic resin composition of the present invention,
When crosslinked, the impact resistance, rigidity and heat resistance, especially among them, are significantly improved as compared with the case without crosslinking. When the ratio of the crosslinked rubbery polymer (rubbery polymer that does not dissolve in the solvent) in the total rubbery polymer in the thermoplastic resin composition of the present invention is defined by the degree of crosslinking, the degree of crosslinking is 30%. Preferably, it is at least 50%.

Next, the compatibilizer which is the component (C) in the styrenic thermoplastic resin composition of the present invention will be described.

When a styrenic elastomer is used as the component (B) of the composition of the present invention, the styrene component is contained in the molecule of the elastomer, so that it is compatible with the polystyrene resin as the component (A). There is a high interfacial adhesion between the component (A) and the component (B), and a composition excellent in impact resistance can be obtained by using only these two components.
When an olefin-based elastomer is used as the component (B), it is not compatible with the polystyrene resin as the component (A). Therefore, the interfacial adhesion between the component (A) and the component (B) is low, and a composition excellent in impact resistance cannot be obtained by using only these two components. Therefore, it is necessary to provide an interfacial adhesion function between the component (A) and the component (B), that is, to improve the compatibility between the components. For this reason, the styrene-based thermoplastic resin composition of the present invention requires a compatibilizer which is the component (C) depending on the material of the component (B). In addition,
When the compatibilizing agent is used in combination also when the component (B) is a styrene elastomer, the impact resistance is improved more than usual.

The compatibilizer of the component (C) is not particularly limited as long as it has a function of compatibilizing the polystyrene resin as the component (A) and the saturated rubbery polymer as the component (B). However, as an example, when the most suitable olefin-based elastomer in the present invention is used as the component (B), those having both a polystyrene component and a polyolefin-based component in the molecule can be mentioned. For example, A is polystyrene or a copolymer of polystyrene, preferably polystyrene, B is polyethylene, polypropylene, an ethylene-α-olefin copolymer mainly composed of ethylene and an α-olefin having 3 to 20 carbon atoms,
Examples include an AB block copolymer comprising hydrogenated polybutadiene and hydrogenated polyisoprene, an A-grafted B copolymer, a B-grafted A copolymer, and the like.
Further, a copolymer in which A is randomly introduced into the B polymer component, specifically, for example, an A monomer component in a B polymer component made of polyethylene, such as an ethylene-styrene random polymer described below, That is, a copolymer into which a styrene monomer is randomly introduced can be used. Here, B may be single or a combination of two or more.

Specific examples thereof include polystyrene-grafted polypropylene, styrene-butadiene or isoprene block copolymer, styrene-hydrogenated butadiene or isoprene block copolymer, ethylene-styrene random copolymer, hydrogenated styrene-
Butadiene random copolymer and the like can be mentioned.
Among these, in particular, styrene-hydrogenated butadiene or isoprene block copolymer itself functions as a compatibilizing agent, and also has an effect of supplementarily increasing impact resistance, and has an effect on weather resistance. Is also most preferable because it is also excellent. When the component (C) is a styrene-hydrogenated butadiene or isoprene block copolymer, this is also the component (B), but the component (B) is a cross-linked component whereas the component (C) is Is distinguished by not being crosslinked.

The compatibilizer as the component (C) in the thermoplastic resin composition of the present invention may be a single type or a combination of a plurality of types.

The composition of the styrenic thermoplastic resin composition of the present invention is such that the polystyrene resin as the component (A) is 60%.
The partially or completely crosslinked saturated rubbery polymer as the component (B) comprises 1 to 40 parts by weight.
The polystyrene resin as the component (A) is 70 to 9
More preferably, the partially or completely crosslinked saturated rubbery polymer as the component (B) is 3 to 30 parts by weight. Furthermore, 75 to 95 parts by weight of a thermoplastic resin mainly composed of a polystyrene resin as the component (A),
It is particularly preferable that the partially or completely crosslinked saturated rubbery polymer (B) be 5 to 25 parts by weight.

It is preferable that the compatibilizer, which is the component (C) used as needed, is less than 50 parts by weight based on 100 parts by weight of the components (A) and (B). More preferably, the amount is less than 25 parts by weight. Further, it is particularly preferred that the amount is less than 10 parts by weight.

When the most suitable olefin elastomer is used as the component (B), the compatibilizer is an essential component. In this case, the lower limit is 0.1% based on 100 parts by weight of the components (A) and (B). It is preferred to exceed 1 part by weight. More preferably, it exceeds 0.5 parts by weight. Furthermore,
It is particularly preferred to exceed 1.0 parts by weight.

When the component (A) is less than 60 parts by weight,
The effect of polystyrene is not exhibited as a polystyrene-based thermoplastic resin composition. On the other hand, if it exceeds 99 parts by weight, the effect of improving the physical properties of the saturated rubbery polymer, that is, the effect of improving the impact resistance is not particularly exhibited. If the amount of the component (C) used in combination as necessary exceeds 50 parts by weight, the compatibilizer is generally expensive, so that the economy is poor. When the component (C) is less than 0.1 part by weight when the olefin-based elastomer is used as the component (B), a phase separation phenomenon or the like occurs and the impact resistance is low.

As described above, the thermoplastic resin molded product of the present invention basically comprises at least a polystyrene resin as the component (A) and a partially or completely cross-linked saturated rubber as the component (B). It is composed of a polymer resin and, if necessary, a compatibilizer which is a component (C). As other components, for example, organic or inorganic fibers such as a softening agent, glass fiber, polyacrylonitrile fiber or carbon fiber, copper or Metal fibers such as brass, whiskers such as potassium titanate, magnesium oxysulfate, and aluminum borate, powders such as calcium carbonate, magnesium carbonate, silica, carbon black, titanium oxide, clay, mica, talc, magnesium hydroxide, and aluminum hydroxide Inorganic filler, polyethylene glycol, dioctyl phthalate (DOP) Other plasticizers etc., organic and inorganic pigments, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers,
Additives such as a flame retardant, silicone oil, an anti-blocking agent, a foaming agent, an antistatic agent, and an antibacterial agent can be used in combination. Among these, the softener has an effect of further improving the impact resistance of a molded product obtained by molding the styrene-based thermoplastic resin composition of the present invention, and is a very effective component. As the softener, a process oil such as a paraffinic or naphthenic oil is particularly preferable. When these softeners are added, the compounding amount is 0.5 to 200 parts by weight, preferably 1 to 100 parts by weight, more preferably 1 to 100 parts by weight based on 100 parts by weight of the components (A) and (B). 50 parts by weight,
Particularly preferably, 1 to 20 parts by weight is used. If the amount is less than 0.5 part by weight, the effect is low when a softener is added. 200
If the amount exceeds the weight part, bleed out of the softener becomes remarkable, which is not preferable.

Next, a method for producing the styrenic thermoplastic resin composition of the present invention will be described. The thermoplastic resin composition of the present invention is not limited to this production method, but can usually be produced by the following method. That is, the polyaxial resin as the component (A), the saturated rubber-like polymer as the raw material of the component (B), a radical initiator, a crosslinking aid and, if necessary, the compatibilizer as the component (C) are biaxially mixed. The rubbery polymer is partially or completely crosslinked by heat treatment with an extruder, a Banbury mixer or the like. In this case, when the compatibilizing agent is a radical initiator, a crosslinking agent is used for crosslinking, the crosslinking is performed without adding the compatibilizing agent, and the compatibilizing agent is added after the crosslinking of the saturated rubbery polymer. The composition of the present invention is obtained by a method or the like. In this method, when the concentration of the saturated rubbery polymer in the polystyrene resin is low, the crosslinking efficiency is low. In this case, a high-concentration saturated rubber-like polymer and polystyrene resin are heat-treated with a twin-screw extruder, a Banbury mixer, etc. in the presence of a radical initiator and a crosslinking aid to partially or completely cross-link the rubber-like polymer. And then kneading or pellet blending a styrene-based elastomer containing a high-concentration partially or completely crosslinked saturated rubbery polymer and a styrene-based resin for component adjustment. And the like.

In the case of producing by the above-mentioned production method, examples of the radical initiator or polymerization initiator to be used include radical initiators such as organic peroxides and organic azo compounds.
Specific examples include 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane,
1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) cyclododecane, , 1-bis (t-butylperoxy) cyclohexane, 2,2-bis (t-
Butylperoxy) octane, n-butyl-4,4-bis (t-butylperoxy) butane, n-butyl-4,
Peroxyketals such as 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-
Dialkyl peroxides such as 2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3; acetyl peroxide, isobutyryl peroxide ,
Diacyl peroxides such as octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide and m-trioyl peroxide T-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxy-
2-ethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate, di-t
-Butylperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-
Peroxyesters such as butylperoxymaleic acid, t-butylperoxyisopropyl carbonate, and cumylperoxyoctate; and t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5 Hydroperoxides such as -dimethylhexane-2,5-dihydroperoxide and 1,1,3,3-tetramethylbutyl peroxide;

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.

When the rubbery polymer is crosslinked by the first or second method, these radical initiators are used in an amount of 0.02 to 3 parts by weight, preferably 0.05 to 3 parts by weight, per 100 parts by weight of the rubbery polymer. Used in an amount of １1 part by weight. The level of crosslinking is mainly determined by this amount. If the amount is less than 0.02 parts by weight, the crosslinking is insufficient, and if the amount exceeds 3 parts by weight, the crosslinking rate is not greatly improved, so that it is not a preferable direction.

Examples of the crosslinking aid 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. These crosslinking aids may be used in combination of two or more.

The crosslinking aid is used in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the saturated rubbery polymer. If the amount is less than 0.1 part by weight, the crosslinking rate is low, which is not preferable. If the amount exceeds 5 parts by weight, the crosslinking ratio is not significantly improved, and an excessive amount of the crosslinking aid remains, which is not a preferable direction.

As a method of crosslinking, it is preferable to use a radical initiator and a crosslinking aid as described above, but in addition, a phenol resin or bismaleimide may be used as a crosslinking agent.

As the equipment for partially or completely crosslinking the saturated rubbery polymer as the component (B) of the composition of the present invention, a Banbury mixer, a kneader, a single screw extruder, a twin screw extruder, or the like is used. it can. In order to achieve particularly efficient crosslinking, a twin-screw extruder is preferably used. The twin-screw extruder is capable of uniformly and finely dispersing the rubber-like polymer and the thermoplastic resin, and can also preferably carry out a cross-linking reaction with a cross-linking agent and a cross-linking aid, and is suitable for continuously producing a cross-linked body. I have. A specific manufacturing method can be manufactured through the following processing steps. That is, a mixture of a saturated rubbery polymer and a polystyrene resin is charged into a hopper of an extruder. The radical initiator and the crosslinking assistant may be added together with the rubbery polymer and the thermoplastic resin from the beginning, or may be added in the middle of the extruder. When oil is added as a softening agent, it may be added from the middle of the extruder, or may be added separately at the beginning and during the middle. A part of the rubbery polymer and the thermoplastic resin may be added in the middle of the extruder. When heated and melted and kneaded in the extruder, the rubber-like polymer and the radical initiator and the crosslinking assistant undergo a crosslinking reaction, and if necessary, an oil or the like is added and melt-kneaded, whereby the crosslinking reaction and kneading are performed. After sufficient dispersion, take out of the extruder. The pellet of the composition of the present invention can be obtained by pelletizing.

The styrenic thermoplastic resin composition of the present invention thus obtained can be used to produce various molded articles by any molding method. As the molding method, injection molding, extrusion molding, compression molding, blow molding, calender molding, foam molding and the like are preferably used.

[0045]

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, and the production methods of the thermoplastic elastomer used for the raw materials and the blending are as follows.

1. Test method (1) Tensile strength Measured at 23 ° C. by a method based on JIS K6251. (2) Tensile elongation Measured at 23 ° C. by a method according to JIS K6251. (3) Flexural modulus Measured at 23 ° C. by a method according to JIS K6758. (4) Izod impact strength Measured at 23 ° C. by a method according to JIS K6758. (V notch, 1/4 inch test) (5) Heat resistance (HDT) Measured by a method in accordance with JIS K7207.

(6) Weather Resistance Evaluation was made using a sunshine weather meter (65 ° C., with rain). Evaluation was made based on the retention rate of Izod impact strength after 500 hours. The retention rate of 80% or less is indicated by x, 80 to 90% by ○, and 90% or more by ９０.

(7) Degree of Crosslinking 0.5 g of the sample was dissolved in a solvent capable of dissolving both the non-crosslinked rubbery polymer and the polystyrene resin, for example, 200 m of xylene.
Reflux for 4 hours in l. The solution is filtered through a filter paper for quantification, the residue on the filter paper is vacuum-dried and quantified, and the ratio of the weight of the residue to the weight of the rubbery polymer in the sample (%)
It was calculated as

2. Raw materials (1) Rubbery polymer (a) Ethylene / octene-1 copolymer Produced by a method using a metallocene catalyst described in JP-A-3-1630088. The ethylene / octene-1 composition ratio of the copolymer was 72/28 (weight ratio) (referred to as TPE-1).

(B) Ethylene / propylene / dicyclopentadiene copolymer Produced by a method using a metallocene catalyst described in JP-A-3-16388. The composition ratio of ethylene / propylene / dicyclopentadiene in the copolymer is 72/2.
4/4 (weight ratio). (Referred to as TPE-2)

(C) Hydrogenated styrene-isoprene block copolymer Septon (trade name 2023) manufactured by Kuraray Co., Ltd. (SEP)
S)

(2) Polystyrene resin (a) Polystyrene (trade name: GP manufactured by Asahi Kasei Corporation)
(B) Impact-resistant polystyrene (trade name: HIPS492R) (trade name: HIPS) manufactured by Asahi Kasei Kogyo Co., Ltd. (c) Poly (styrene-acrylonitrile) (trade name: 769) manufactured by Asahi Kasei Kogyo Co., Ltd. (Referred to as AS)

(3) Radical initiator 2,5-dimethyl-2,5-bis (t-manufactured by NOF Corporation)
Butyl peroxy) Hexane (trade name: Perhexa 25B) (referred to as POX)

(4) Crosslinking assistant divinylbenzene (referred to as DVB) manufactured by Wako Pure Chemical Industries, Ltd.

(5) Softener (paraffin oil) Diana Process Oil (trade name PW-3) manufactured by Idemitsu Kosan
80)

(6) Compatibilizer (a) Hydrogenated styrene-butadiene block copolymer, manufactured by Asahi Kasei Kogyo Co., Ltd., Tuftec (styrene content: 60)
%) (Referred to as HTR)

(B) Styrene-grafted polypropylene Modiper (Styrene content: 30 manufactured by NOF Corporation)
%) (Product name A3100) (referred to as SGP)

(C) Ethylene-styrene random copolymer Produced by the method described in JP-A-7-70223. The ethylene / styrene composition ratio of the copolymer is 40 /
60 (weight ratio). (Referred to as ESP)

(D) Epoxidized styrene / hydrogenated conjugated diene copolymer Epofriend (trade name: A102, manufactured by Daicel Co., Ltd.)
0) (referred to as E-HTR)

Examples 1 to 5, Comparative Example 1 Using a twin screw extruder (40 mmφ, L / D = 47),
PE-1 / PS / POX / DVB = 76.0 / 24.0
/0.50/1.0 (weight ratio) and melt extrusion was performed at a cylinder temperature of 220 ° C. A pellet was obtained by injecting 46 parts by weight of a softening agent (paraffin oil) with respect to a total amount of 100 parts by weight of TPE-1 and PS from an injection port at the center of the extruder (referred to as TPV-1). The degree of crosslinking of the rubbery polymer therein was 82%. The pellets obtained, the compatibilizer and PS were mixed so as to have the composition shown in Table 1, and extruded with a twin-screw extruder. The pellet was molded by an injection molding machine (Toshiba IS45PNV) to obtain a molded product.
Table 1 shows the characteristics of the molded product.

Example 6 TPV-1 pellets, compatibilizers and PS pellets were pellet-blended with the same composition as in Example 2 without being melted and extruded, and the mixed pellets were subjected to an injection molding machine (Toshiba IS4
5PNV) to obtain a molded product. Table 1 shows the characteristics of the molded product.

Example 7 Using a twin screw extruder (40 mmφ, L / D = 47),
PE-2 / PS / POX / DVB = 76.0 / 24.0
/0.50/1.0 (weight ratio) and melt extrusion was performed at a cylinder temperature of 220 ° C. A pellet was obtained by injecting 46 parts by weight of a softening agent (paraffin oil) with respect to a total amount of 100 parts by weight of TPE-2 and PS from an inlet at the center of the extruder (referred to as TPV-2). The degree of crosslinking of the rubbery polymer therein was 81%. The pellets obtained, the compatibilizer and PS were mixed so as to have the composition shown in Table 1, and extruded with a twin-screw extruder. The pellet was molded by an injection molding machine (Toshiba IS45PNV) to obtain a molded product.
Table 1 shows the characteristics of the molded product.

Example 8 Using a twin-screw extruder (40 mmφ, L / D = 47),
EPS / PS / POX / DVB = 60.0 / 40.0 /
0.35 / 0.7 (weight ratio) and cylinder temperature 2
Melt extrusion was performed at 20 ° C. A pellet was obtained by injecting 18 parts by weight of a softening agent (paraffin oil) with respect to a total amount of 100 parts by weight of SEPS and PS from an injection port at the center of the extruder (referred to as TPV-3). The degree of crosslinking of the rubbery polymer was 63%. The obtained pellets and PS were mixed so as to have the composition shown in Table 1, and extruded with a twin-screw extruder. This pellet is injected into an injection molding machine (Toshiba IS45
PNV) to obtain a molded product. Table 1 shows the characteristics of the molded product.

Comparative Example 2 HIPS was molded by an injection molding machine (Toshiba IS45PNV) to obtain a molded product. Table 1 shows the characteristics of the molded product.

Example 9 Using a twin screw extruder (40 mmφ, L / D = 47),
PE-1 / AS / POX / DVB = 55.0 / 45.0
/0.50/1.0 (weight ratio) and melt-extruded at a cylinder temperature of 220 ° C. (referred to as TPV-4).
The degree of crosslinking of the rubbery polymer in the pellets was 73%. The obtained pellets, the compatibilizer and AS were mixed so as to have the composition shown in Table 1, and extruded with a twin-screw extruder. The pellet was molded by an injection molding machine (Toshiba IS45PNV) to obtain a molded product. Table 1 shows the characteristics of the molded product.

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[Table 1]

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The styrenic thermoplastic resin composition of the present invention is a material having excellent weather resistance and impact resistance. This material is used in applications such as packaging materials, housing-related materials, automotive materials, OA equipment materials, tools, daily necessities, etc., and particularly in applications where impact-resistant polystyrene (HIPS) is difficult to use due to weather resistance. It can be deployed and plays a large role in the industrial world.

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) C08L 23:00) C08L 23:00) (C08L 25/04 (C08L 25/04 23:16) 23:16) (C08L 25/04 (C08L 25/04 23:08) 23:08) (72) Inventor Takeshi Yasui 1-3-1 Yoko, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Asahi Kasei Kogyo Co., Ltd. F-term (reference) 4J002 AC082 AC083 BB052 BB103 BB152 BC031 BC041 BC043 BC052 BC053 BP012 BP013 BP033

Claims (6)

[Claims] (1) at least (A) a polystyrene resin: 60 to 99 parts by weight, (B) a partially or completely cross-linked saturated rubbery polymer: 1 to 40 parts by weight, and (C) a compatibilizer: ( An impact-resistant polystyrene-based thermoplastic resin composition comprising less than 50 parts by weight per 100 parts by weight of component (A) and component (B). 2. The impact-resistant polystyrene-based thermoplastic resin composition according to claim 1, wherein the partially or completely crosslinked saturated rubber-like polymer as the component (B) is a styrene-based and / or olefin-based elastomer. object. 3. The partially or completely crosslinked saturated rubbery polymer as the component (B) is an olefin-based elastomer, and the component (C) is composed of the components (A) and (B) 100.
2. The impact-resistant polystyrene-based thermoplastic resin composition according to claim 1, wherein the amount is more than 0.1 part by weight and less than 50 parts by weight. 4. The partially or completely crosslinked saturated rubbery polymer as the component (B) is a styrene-based elastomer, and the component (C) is added to the component (A) and 100 parts by weight of the component (B). The impact-resistant polystyrene-based thermoplastic resin composition according to claim 1, wherein the amount is 0 to less than 50 parts by weight. 5. The impact-resistant polystyrene-based elastomer according to claim 1, wherein the olefin-based elastomer is an ethylene / α-olefin-based copolymer mainly composed of ethylene and an α-olefin having 3 to 20 carbon atoms. Thermoplastic resin composition. 6. The compatibilizing agent as the component (C) is such that A is randomly added to the AB block copolymer, the A grafted B copolymer, the B grafted A copolymer and the B polymer component. One or more copolymers selected from the introduced copolymers [where A is polystyrene, B is polyethylene, polypropylene, ethylene and ethylene and α-olefin having 3 to 20 carbon atoms. one or two or more polymers selected from α-olefin-based copolymers, hydrogenated polybutadienes, and hydrogenated polyisoprenes]. Plastic resin composition.