JPH0778168B2 - Thermoplastic resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a novel thermoplastic resin composition. Specifically, rigidity, impact resistance and molding processability obtained by dynamically heat-treating a mixture of a thermoplastic resin and a rubber-like substance having a carbon-carbon unsaturated double bond using a specific compound. The present invention relates to a thermoplastic resin composition having an excellent balance of the above, or an excellent balance of flexibility and molding processability.

(Prior Art) A thermoplastic resin is used in a wide range of industrial fields as a material having excellent moldability, but its field of application has been expanded by further blending it with a rubber-like substance to modify it. It is also known to accelerate the effects of the above-mentioned blends, such as the improvement of impact resistance and the increase of rubber-like properties, by dynamically heat-treating the mixture thus obtained. However, the compositions obtained by these dynamic heat treatment techniques have been desired to be improved in the following points.

In the method of dynamically heat treating a crystalline polypropylene resin and an olefin copolymer elastomer in the presence of an organic peroxide (Japanese Patent Publication Nos. 53-34210, 55-23584, 62-938) , A composition having good fluidity at the time of injection molding can be obtained, but when an amount of organic peroxide necessary for exhibiting the effect is added, the organic peroxide remaining in the composition is thermally stable. And deteriorates weather resistance. Further, as a result of rapid thermal decomposition of the organic peroxide, a molecular cleavage reaction is unavoidable, which results in deterioration of mechanical properties or deterioration of drawdown resistance due to increase in melt flow rate of polypropylene resin and parison. Rough skin was a problem. Further, this method cannot be used for a resin such as a polyethylene resin which is cross-linked and gelled in the presence of an organic peroxide, because the flow property of the composition is significantly deteriorated.

A method of dynamically heat-treating a crystalline polypropylene resin and an olefin copolymer elastomer in the presence of a quinone dioxime or a phenol / formaldehyde resin (Japanese Patent Publication Nos. 54-19421 and 58-46138) is also available. Although proposed, quinonedioximes are dark purple, so that the degree of freedom in coloring the composition is greatly limited, and there is a problem that an irritating odor is generated during heat treatment. In the case of heat treatment with phenol-formaldehyde resin, it is necessary to add a halide in order to increase the efficiency of heat treatment, but this causes the composition to be colored dark black, greatly limiting the degree of freedom in coloring the composition. . Further, it is difficult to say that the composition obtained by these methods has good flow characteristics during molding.

(Problems to be Solved by the Invention) In view of the above points, the present invention provides a thermoplastic resin composition excellent in rigidity, heat resistance, impact resistance or flexibility as well as flow characteristics in large-sized injection molding. The purpose is to

(Means for Solving the Problems) As a result of intensive studies conducted by the present inventors in view of the above objects, a mixture of a thermoplastic resin containing no carbon-carbon unsaturated bond and a rubber-like substance having an unsaturated bond is obtained. It was found that a resin composition for the above-mentioned purpose, which is significantly superior to the conventional composition, can be obtained by dynamically heat-treating the resin composition in the presence of a compound having a 1,2-diphenylethane skeleton. The present invention has been reached.

That is, the present invention is a thermoplastic resin substantially free of carbon-carbon unsaturated bond (hereinafter referred to as a resin component (A)) and a rubber-like substance having a carbon-carbon unsaturated bond (hereinafter,
A mixture composed of a resin component (B)) is mixed with a 1,2-diphenylethane compound (hereinafter referred to as an additional component (a)) and, if necessary, an organic peroxide (hereinafter referred to as an additional component (b)) and / or Alternatively, the present invention provides a thermoplastic resin composition comprising a composition obtained by dynamically heat-treating in the presence of a cross-linking aid (hereinafter referred to as additive component (c)).

Hereinafter, the present invention will be described in detail.

First, the resin component (A) used in the present invention is widely selected from resins that do not substantially contain an olefinic carbon-carbon unsaturated compound, and specific examples thereof include crystalline polypropylene and propylene / α-olefin.・ Random copolymer, high-density polyethylene, high-pressure low-density polyethylene, linear low-density polyethylene, extremely low-density polyethylene (density 0.910 g / cm ³ or less), ethylene / α-olefin copolymer rubber, ethylene-non-polymer Examples thereof include polyolefin resins such as saturated carboxylic acid ester copolymers, polystyrene resins, polyacrylonitrile resins, polymethacrylate resins, polyamide resins, polyester resins, polyacetal resins and mixtures thereof.
Among these, it is preferable to use a polyolefin resin or a mixture thereof from the viewpoint of compatibility with a rubber-like substance (resin component (B)) described later and properties of the resulting composition.

Next, the resin component (B) is a rubber-like substance having an olefinic carbon-carbon unsaturated bond, and specific examples thereof include natural rubber, isoprene rubber, butadiene rubber, 1,2
-Polybutadiene rubber, styrene-butadiene-random copolymer rubber, chloroprene rubber, nitrile rubber, butyl rubber and other rubbers, and styrene-butadiene-styrene block copolymer (hereinafter abbreviated as SBS), styrene-isoprene-styrene block Copolymer (hereinafter SIS
And a copolymer elastomer such as ethylene-propylene-diene / block copolymer (hereinafter abbreviated as EPDM). Of these, 1,2-polybutadiene rubber, SBS, SIS and EPDM are available in the form of pellets, so not only can they be easily weighed and handled during compounding, but they can also be selected for the equipment type for producing the composition. This is preferable because the degree of freedom is increased.

There is no particular limitation on the diene component contained in EPDM, and any of the currently available ethylidene norbornene, dicyclopentadiene, 1,4-cyclohexadiene and the like can be used, but when ethylidene norbornene is used, dynamic heat treatment can be performed. It is particularly preferable because the effect is easily exhibited.

Further, these rubber-like substances may be used not only alone but also as a mixture of two or more kinds, if necessary. In particular, by containing nitrile rubber, an elastomer composition having extremely excellent oil resistance can be obtained.

The mixing ratio of the resin components (A) and (B) is 98 for (A).
~ 10 wt%, preferably 95-30 wt%, (B) 2-90
%, Preferably 5 to 70% by weight. As the blending ratio of (B) in the composition increases, the composition has a good balance of rigidity, impact resistance, and flow characteristics during large-scale injection molding, and an elastomer having a good balance of flexibility and flow characteristics. Because it changes continuously to the composition of
The blending ratio may be determined from the above range according to the purpose. When the content of (B) is less than 2% by weight, the effect of improving the impact resistance is insufficient, and when it exceeds 90% by weight, the fluidity during molding remarkably decreases.

The additive component (a) is a compound having a skeleton structure of 1,2-diphenylethane, and the carbon-carbon bond of the ethane skeleton in the formula (a) is radically cleaved by heating or light irradiation. A typical example of the additive component (a) can be represented by the formula (a) by a chemical formula.

However, R may be the same or different and represents hydrogen, an alkyl group or a phenyl group. Particularly preferred are compounds in which all or part of R is a lower alkyl group such as methyl and ethyl.

Such a compound can be arbitrarily synthesized by applying a known chemical reaction, but as the currently available compound, the commonly known dicumyl, that is, 1,2-diphenyl-1,1,2,2-tetramethylethane is used. Can be mentioned.

Conventionally, there has been known a method of graft-polymerizing a modifier having a double bond such as maleic anhydride to polyolefin by using a substance of the same type as the additive component (a) as a radical generator (Japanese Patent Application Laid-Open (JP-A)). No. 61-276808, JP-A No. 62-167308), there is no report to improve the balance of a wide range of properties as a thermoplastic resin by using it during dynamic heat treatment of polyolefin and rubber-like substances.

Examples of the organic peroxide that is an optional additional component (b) include, for example, t-butyl hydroperoxide, 2- (4-isopropylphenyl) -2-propyl hydroperoxide, di-t-butyl peroxide, t-. Butyl t
-Cumyl peroxide, dicumyl peroxide, 2,
5-Dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-Dimethyl-2,5-di (t-butylperoxy)
Hexin, 1,3-bis [α- (t-butylperoxy)
Isopropyl] benzene, 1,3-bis [α- (t-butylperoxy) isobutyl] benzene, 1,1-bis (t
-Butylperoxy) -3,3,5-trimethylcyclohexane, dilauroyl peroxide, dibenzoyl peroxide, bis (4-chlorobenzoyl) peroxide, t-butyl peroxybenzoate and the like. In the present invention, the half-life of the organic peroxide to be used is not particularly limited, and therefore, it can be widely selected from the commercially available organic peroxides as described above. In this respect, in the above-mentioned Japanese Patent Publication No. 55-23584, the organic peroxide is limited to the one-minute half-life temperature of 160 to 260 ° C., which suggests that the effect is different from that of the present invention. .

As the crosslinking aid used as the optional addition component (c) in the present invention, a polyfunctional monomer added when a rubber-like substance such as an ethylene-propylene copolymer rubber is crosslinked with a peroxide can be used. As specific examples, trimethylolpropane trimethacrylate, higher esters of methacrylic acid typified by ethylene dimethacrylate, polyfunctional vinyl monomers typified by triallyl cyanurate, diallyl phthalate, p-quinone dioxime, p -Quinone bis (O-benzoyl oxime)
And bismaleimides typified by N, N'-m-phenylene bismaleimide and N, N'-ethylene bismaleimide. The selection of these crosslinking aids is arbitrary, but the resin component (B) is EP
In the case of DM, it is preferable to use bismaleimides in terms of enhancing the effect of the dynamic heat treatment described later.

In the present invention, the mixture of the above 3 to 5 kinds of components is dynamically heat treated. The dynamic heat treatment means that the mixture is melt-kneaded and the boiling xylene insoluble content in the composition after kneading is increased as compared with the value before the kneading. The effect of the present invention is achieved by this heat treatment,
In general, the greater the amount of boiling xylene insolubles, the greater the improvement in various effects. It is not preferable that the treatment temperature is within the temperature range above the melting point or softening point and below the decomposition point of the resin component (A), and is lower than the 1-minute half-life temperature of the additive component (a) by 20 ° C. or more.

The main factor for increasing the boiling xylene insoluble content is the addition amount of the additional component (a) or (a) and (b) and / or (c). Of these, the addition of the additional components (a) and (c) The amount can be appropriately selected depending on the melt-kneading apparatus and conditions. If added excessively, bleeding of the added component, coloring of the composition or increase in cost, etc.,
The amount to be added may be limited in consideration of these factors. The practical addition amount is usually resin component (B) for both (a) and (c).
0.01 to 5 parts by weight, preferably 0.0
5 to 3 parts by weight.

On the other hand, the addition amount of the additive component (b) is 0.01 to 100 parts by weight based on the total amount of the resin components (A) and (B).
It is 0.5 part by weight, preferably 0.1 part by weight or less. When adding a large amount of organic peroxide, heat resistance, weather resistance, mechanical properties,
Since problems such as deterioration of surface gloss and generation of odor are likely to occur, it is preferable to keep the amount as small as possible.

In order to enhance the effect of the present invention after the dynamic heat treatment,
Before adding the additive component (a) or (a) and (b) and / or (c), only the resin components (A) and (B) are melt-kneaded in advance and dispersed as well as possible. It is preferable. Further, after melt-kneading the resin components (A) and (B), the resin component (A) is added again together with the addition component (a) or (a) and (b) and / or (c) to dynamically add the components. Heat treatment can also be performed. Further, after melt-kneading the resin components (A) and (B), heat treatment is performed dynamically in the presence of the additive component (a) or (a) and (c), and then the additive component (b) is added. In addition, heat treatment may be performed. There is no particular limitation on the order of addition when two or more of the additional components (a), (b) and (c) are added.

As the melt-kneading device for performing the dynamic heat treatment, conventionally known devices such as an open type mixing roll, a non-open type Banbury mixer, an extruder, a kneader and a twin screw extruder can be used. The conditions for carrying out the present invention with the above-described composition are a kneading temperature of 120 to 280 ° C. and a heat treatment time of 30 sec.
A range of up to 20 min is preferred.

In the present invention, a softening agent may be added to improve moldability and flexibility. As a mineral oil softener,
The same as the so-called extender oil, which is used mainly for the purpose of improving the processability, the effect of increasing the amount of the filler and the dispersibility of the filler during the processing of rubber, is used. These are petroleum components with a high boiling point and are classified into paraffinic, naphthenic and aromatic types. In the present invention, not only these petroleum fractions but also synthetic oils such as liquid polyisobutene can be used. The compounding amount is 5 to 300 parts by weight, preferably 20 to 150 parts by weight, based on 100 parts by weight of the resin component (B). If the compounding amount is less than 5 parts by weight, the effect cannot be obtained, and if it exceeds 300 parts by weight, the strength and heat resistance are remarkably lowered. The addition timing is not particularly limited, but it is preferable to add the resin components (A) and (B) when melt-kneading.

In addition, stabilizers, antioxidants, ultraviolet absorbers, lubricants, foaming agents, antistatic agents, flame retardants, plasticizers, dyes, pigments, etc., talc, calcium carbonate, carbon as necessary for the composition of the present invention. Various fillers such as black, mica, glass fiber, carbon fiber, aramid resin, and asbestos can be appropriately mixed.

(Effects of the Invention) The thermoplastic resin composition of the present invention not only exhibits excellent performance in terms of balance such as rigidity, heat resistance, impact resistance, oil resistance, and flow characteristics required for large-sized injection molding. The improvement in the balance between the flexibility and the fluidity is also observed, and the drawbacks of the conventional thermoplastic resin are remarkably improved.

(Examples and Comparative Examples) Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto. Unless otherwise specified, test pieces obtained by injection molding were used after annealing treatment. The method for producing the composition, the conditions for producing the test piece by injection molding, and the test method are as follows: Method for producing the composition 1) The resin components (A) and (B) were blended in a predetermined mixing ratio, and Henschel was used. Mix with a mixer.

2) A twin-screw continuous kneading extruder (30 mm
φ, manufactured by Plastic Engineering Laboratory Co., Ltd., and melt-kneaded at a resin temperature of 160 to 180 ° C. and a rotation speed of 200 rpm. At this time, a softener was added from a reciprocating metering pump connected to the vent according to predetermined conditions.

3) A predetermined amount of additive component (a),
Alternatively, the additive components (a) and (b) and / or (c) were added and mixed by stirring with a Henschel mixer.

4) The mixture obtained above was dynamically heat-treated by melt-kneading with the twin-screw continuous kneading extruder used in 2).
At this time, the temperature of the composition at the exit of the extruder and the residence time in the extruder were measured and controlled to adjust the conditions. These temperatures and times are shown in Table 1, Table 2 and Table 3 as heat treatment conditions.

Conditions molding machine IS-90B of the injection molding (Toshiba Machine Co., Ltd.) Injection pressure 1,000kg / cm ² molding temperature 180 to 230 ° C. Mold temperature 50 ° C. Test and measurement methods (durometer hardness) H _{D D:} JIS K6760 According to JIS K7215.

H _D A: According to ISO 868.

(Melt flow rate (MFR)) According to JIS K6758, JIS K7210. However, a load of 10 kg was used for Examples 9-14 and Comparative Examples 9-14.

(Tensile breaking strength) and (Tensile breaking elongation) According to JIS K6758, JIS K7113. However, a test speed of 200 mm / min was used for Examples 9 to 14 and Comparative Examples 9 to 14.

(Flexural modulus) According to JIS K6758, JIS K7203.

(Permanent elongation) According to JIS K6301. However, 100% extension, type 3 dumbbells are used.

(Vicat softening temperature) According to JIS K6758, JIS K7206. However, for Examples 9 to 14 and Comparative Examples 9 to 14, a test load of 250 kg was used.

(Izod impact value) According to JIS K6758, JIS K7110.

(Embrittlement temperature) According to JIS K6760, JIS K7216.

(Boiling xylene insoluble matter) A film of 20 mm x 50 mm x 0.2 mm was produced by press molding, put in a wire mesh of 120 mesh and dipped in boiling xylene for 5 hours. The weight before and after the immersion was measured, and the boiling xylene insoluble matter was determined from the following formula: (Oil resistance test) According to JIS K6301 (immersion test).

(Glossiness) According to JIS Z 8741. Measurement at an incident angle of 60 ° (flow mark) The corrugated pattern on the surface of the injection-molded flat plate was visually evaluated.

(Appearance of parison) A parison was molded by an extruder for hollow molding, and its surface was visually observed and evaluated.

The flow marks and the appearance of the parison were evaluated in the following three grades: ◎ Very good, ○ good, × bad.

Examples 1 and 2, Comparative Examples 1 and 2 Resin components (A) and (B) and additive component (a),
The following were used as (b) and (c).

Resin component (A): (A ₁ ) polypropylene (1) (MFR1.5g / 10min; trade name: Nisseki Polypro J120G, manufactured by Nippon Petrochemical Co., Ltd.) Resin component (B): (B ₁ ) ethylene-propylene -Ethylidene norbornene copolymer (Moonie viscosity ML _{1 + 4} (100 ℃) 88, iodine value 15; trade name: J
SR EP57P, manufactured by Nippon Synthetic Rubber Co., Ltd. Additive component (a): (a) 1,2-diphenyl-1,1,2,2-tetramethylethane (commonly called dicumyl) (1 minute half-life temperature 230 ° C; Product name: Percadox 30, manufactured by Kayaku Nouri Co., Ltd. Additive component (b): (b) 1,3-bis [α- (t-butylperoxy) isopropyl] benzene (1 minute half-life temperature 175 ° C; Trade name: Perbutyl P, manufactured by NOF CORPORATION Additive component (c): (c) N, N'-m-phenylene bismaleimide (trade name: Barnock PM, manufactured by Ouchi Shinko Chemical Co., Ltd.) A composition was produced by using the components of Example 1 under the blending ratio and heat treatment conditions shown in Table 1, and injection molding was performed to prepare a test piece, which was then tested. The results are shown in Table 1.

The mixing ratio of the additive components (a), (b), and (c) in Table 1 is 100 when the total amount of the resin components (A) and (B) is
The values are parts by weight (the same applies to each table below).

Examples 3 to 5, Comparative Examples 3 and 4 Table 1 was prepared in the same manner as described above except that the following resin components (A) and (B) were used and the following components were added as the additive component (c). The composition was produced by treating with the compounding ratio and the heat treatment conditions shown in, and injection molding was performed. The results are shown in Table 1.

Resin component (A): (A ₂ ) Polypropylene (2) (MFR1.5g / 10min; Trade name: Nisseki Polypro J620G, manufactured by Nippon Petrochemical Co., Ltd.) Resin component (B): (B ₂ ) Styrene-butadiene -Styrene / block copolymer (styrene / butadiene weight ratio = 28/72; trade name: Califlex TRKX-65, manufactured by Shell Chemical Co., Ltd.) Additive component (c): (c) divinylbenzene (Tokyo Chemical Industry ( Co., Ltd.) Example 6, Comparative Example 5 A composition was prepared by using the same components as above except that the following resin components (B) were used, and treating at the blending ratio and heat treatment conditions shown in Table 1. Then, injection molding was performed. The test results are shown in Table 1.

Resin component (B): (B ₃ ) 1,2-polybutadiene rubber (trade name: JSR RB805, manufactured by Japan Synthetic Rubber Co., Ltd.) Example 7, Comparative Examples 6, 7 The following resin components (A) were used. Using the same components as described above except using, a composition was produced by treating with the mixing ratio and heat treatment conditions shown in Table 1, and injection molding was performed. The test results are shown in Table 1.

Resin component (A): (A ₃ ) High density polyethylene (MFR 0.3g / 10min; trade name: Nisseki Stafren E703, manufactured by Nippon Petrochemical Co., Ltd.) Example 8, Comparative Example 8 Resin component (A) and softening The same components as described above were used except that the following agents were used, and the composition was produced by treating with the compounding ratios and heat treatment conditions shown in Table 2, and injection molding was performed. The results are shown in Table 2.

Resin component (A): (A ₄ ) Polypropylene (3) (MFR1.5g / 10min; Trade name: Nisseki Polypro J725N, manufactured by Nippon Petrochemical Co., Ltd.) Softener: (C ₁ ) Paraffin-based process oil (Product Name: Nisseki Komorex EL30, Nippon Oil Co., Ltd.
Manufacture) Examples 9 to 11, Comparative Examples 9 and 10 Using the same components as above except that the following was used as the resin component (B) and the following was added as the additional component (b), A composition was produced by treating under the compounding ratio and heat treatment conditions shown in No. 3, and injection molding was performed. The test results are shown in Table 3.

Resin component (B): (B ₃ ) Nitrile rubber (Acrylonitrile content 48% by weight, Mooney viscosity ML _{1 + 4}
(100 ° C.) 45, trade name: N215SL, manufactured by Nippon Synthetic Rubber Co., Ltd. Additive component (b) (b ₂ ) 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane (1 Minute half-life temperature 148 ° C; Trade name: Perhexa 3M, manufactured by NOF CORPORATION (b ') Phenolic resin A resin prepared by the following formulation was used: Examples 12 to 14, Comparative Examples 11 to 14 Resin components (A) and components similar to those described above except that the following softeners were used, and the compositions were obtained by treating at the compounding ratios and heat treatment conditions shown in Table 4. The product was manufactured and injection-molded. The results are shown in Table 4.

Resin component (A): (A ₅ ) Ultra low density polyethylene (MFR1.0g / 10min; Product name: Nisseki Softlex D9010,
Softener: (C ₂ ) Liquid polybutene (trade name: Nisseki Polybutene LV100, manufactured by Nippon Oil Co., Ltd.) <Explanation of symbols in the table> A ₁ : Polypropylene (1) (Nisseki) Polypro J120G) A ₂ : Polypropylene (2) (Nisseki Polypro J620G) A ₃ : High density polyethylene (Nisseki Staflen E703) A ₄ : Polypropylene (3) (Nisseki Polypro J725N) B ₁ : EPDM (JSR EP57P) B ₂ : SBS (Califlex TRKX-65) B ₃ : 1,2-Polybutadiene rubber (JSR RB805) B ₄ : Nitrile rubber (N215SL) C ₁ : Paraffin-based process oil (Nisseki Koumorex
EL30) C _2: liquid polybutene (Nisseki Polybutene LV 100) a: 1,2-diphenyl-1,1,2,2-tetramethyl-ethane (Perkadox 30) b _1: 1,3- bis [alpha-(t - butylperoxy) isopropyl] benzene (Perbutyl P) b _2: 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane peroxide hexa 3M) b ': phenol resin _{(PS 2608 + SnCl 2 + ZnO} ) c ₁ : N, N′-m-phenylene bismaleimide (Barnock
PM) c ₂ : divinylbenzene

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Claims (3)

[Claims] 1. A thermoplastic resin containing substantially no carbon-carbon unsaturated bond (hereinafter referred to as resin component (A)) and a rubber-like substance having carbon-carbon unsaturated bond (hereinafter referred to as resin component (B)). A mixture of 1,2-diphenylethane compound (hereinafter referred to as an additional component (a)) and, if necessary, an organic peroxide (hereinafter referred to as an additional component (b)) and / or a crosslinking auxiliary ( Hereinafter, a thermoplastic resin composition comprising a composition obtained by dynamically heat treating in the presence of an additive component (c)). 2. The thermoplastic resin composition according to claim 1, which contains a mineral-based or synthetic oil-based softening agent in an amount of 300 parts by weight or less per 100 parts by weight of the resin component (B). 3. The 1,2-diphenylethane compound is 1,2-diphenyl-1,1,2,2-tetramethylethane.
Or the thermoplastic resin composition according to 2.