JPH02178345A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition improved in molding processability by blending a specified amount of specific methacrylate polymer with a high- nitrile elastomer-aromatic vinyl-vinyl cyanide copolymer. CONSTITUTION:The objective composition can be obtained by blending (A) 100 pts.wt. of an elastomer-aromatic vinyl-vinyl cyanide copolymer containing 40-90 (pref. 40-75) wt.% of vinyl cyanide unit and/or an aromatic vinyl-vinyl cyanide copolymer containing 40-90wt.% of vinyl cyanide unit with (B) 0.5-10 pts.wt. of a methacrylate polymer containing >=25 (pref. >=40) wt.% of methacrylate unit.

Description

DETAILED DESCRIPTION OF THE INVENTION BACKGROUND OF THE INVENTION INDUSTRIAL APPLICATION This invention relates to improved processability high nitrile polymers. More specifically, the present invention improves the processability of a rubber elastomer-aromatic vinyl-vinyl cyanide copolymer or an aromatic vinyl-vinyl cyanide copolymer having a high content of vinyl cyanide units. The present invention relates to a resin composition.

Conventional technology Rubber elastic body-aromatic vinyl-vinyl cyanide copolymer is well known as an impact-resistant resin, and in particular, the rubber elastic body is a conjugated diene rubber (specifically, a butadiene polymer). ABS resin has been praised as one of the so-called engineering plastics.

On the other hand, aromatic vinyl-vinyl cyanide copolymers are called AS resins because of their typical styrene-acrylonitrile copolymers, and are also commonly used plastic materials.

Both of these resins (in the following explanation, for simplicity, they will be referred to as ABS resin and AS resin, respectively) generally have excellent chemical resistance, dimensional stability, and moldability. Therefore, it is widely used in home appliances, industrial parts, etc.

However, the chemical resistance of these resins is not sufficient. copolymerization with polymers, mixing and kneading, (4) post-treatments such as annealing and painting of molded products, etc. have been carried out.

However, (1) has poor moldability, (3) has poor compatibility and reduced dimensional stability, and (4) has increased cost, etc., and essentially has poor chemical resistance etc. It was not possible to improve performance.

On the other hand, regarding (2), although increasing the amount of acrylonitrile contained in ABS and AS resins is very effective in improving chemical resistance, there are problems with compounding or moldability. there were.

Problems to be Solved by the Present Invention Problem (2) above specifically manifests as follows. That is, AB containing a large amount of acrylonitrile
Since S resin or AS resin has a high adhesion force to metal in the molten state, it may wrap around the screw of an extruder or injection molding machine, resulting in unstable discharge volume in an extruder and short measuring time in an injection molding machine. In addition to causing operational problems such as instability, problems with the molded parts, such as burning of the molded parts due to prolonged residence in the cylinder, can occur.
Yellowing etc. tend to occur, so high nitrile ABS
Although resins and AS resins are high-performance resins, they have not been well-received in the market.

The present invention is an ABS resin that can prevent this winding around the screw, further reduce the thermal history, and obtain molded products with excellent surface appearance, stable production, and excellent chemical resistance. Alternatively, the purpose is to produce AS resin.

[Summary of the invention]

Problems to be Solved by the Invention As a result of intensive studies in view of the above circumstances, the present inventor Toru has formulated a methacrylate polymer containing 25% by weight or more of methacrylate units into an ABS resin or AS resin containing 40 to 90% by weight of acrylonitrile. By doing so, there is no adhesion of molten resin to the screw or nozzle part of the molding machine during injection molding, and no stagnation of molten resin in the screw or die part of the extruder during extrusion molding, in other words, it is stable. The present invention was completed based on the discovery that a resin composition that can be molded in a measured amount of time or discharged amount can be obtained.

That is, the thermoplastic resin composition according to the present invention comprises a rubber elastomer-aromatic vinyl-vinyl cyanide copolymer containing 40 to 90% by weight of vinyl cyanide units and/or 40 to 90% by weight of vinyl cyanide units. 67 am aromatic vinyl-vinyl cyanide copolymer 100 parts by weight,
It is characterized in that it consists entirely of 0.5 to 10 parts by weight of a methacrylate polymer containing 25% by weight or more of methacrylate units.

Effects of the Invention According to the present invention, the molding problems observed in high nitrile ABS resins and AS resins are solved, and the heat '1iIt! ! The l-based resin composition has improved stability against abrasive penetration in extruders and injection molding machines, and improved surface appearance due to reduced thermal history.

To improve moldability, high nitrile ABS resin and AS
The amount of acrylate polymer added to the resin is extremely small.
The fact that the desired effect can be obtained with i (details will be described later) is considered to be an old fashioned phenomenon.

[Detailed description of the invention]

The thermoplastic resin composition according to the present invention is made of high nitrile ABS.
It is made by blending an acrylate polymer with a resin or high nitrile AS resin.

1. Hynitrile ABS Resin In the present invention, this resin generally refers to a rubber elastomer hexa-aromatic vinyl/vinyl cyanide copolymer.

The "rubber elastic body" in such resins includes (a) polymers of conjugated dienes, especially butadiene, such as polybutadiene, butadiene-styrene copolymers, butadiene-acrylonitrile copolymers, and others; (b) acrylic rubber; For example, butyl acrylate-acrylonitrile copolymer,
(c) Ethylene propylene rubber, especially ethylene-propylene-nonconjugated diene copolymer known as EPDM, such as ethylene-propylene-ethylidene norbornene copolymer, and others.

Among these, those having ethylenically unsaturated bonds, especially conjugated diene polymers and EPDM, especially the former, are representative since they serve as the "backbone" polymer of the graft copolymer. Acrylic rubber is also an important rubber elastic body in order to obtain the composition of the present invention having sufficient heat resistance, oil resistance, and aging resistance.

Specifically, the aromatic vinyl monomer to be copolymerized with such a rubber elastic body is styrene, a core and/or
Side chain substituted thretins, vinylnaphthalenes, core and/or side chain substituted vinylnaphthalenes, and others. Substituents in this case are lower alkyl and halogen (especially chlorine)
is typical. Therefore, specific examples of aromatic vinyl monomers include styrene, α-methyl≠styrene, vinyltoluene,
These include chlorostyrenes, vinylnaphthalene, etc.

These may be a mixture.

The other vinyl cyanide monomer is specifically acrylonitrile, methacrylonitrile, α-chloroacrylonitrile, or the like. These may be a mixture.

In the present invention, the term "rubber elastomer-aromatic vinyl-vinyl cyanide copolymer" includes, in addition to these three essential components, a small amount of co-111 ffi copolymer. . Such comonomers include (meth)acrylic esters (especially lower alkyl esters), crosslinking monomers such as divinylbenzene, ethyl glycol di(meth)acrylate, and others. Note that "(meth)acrylic acid" or "(meth)acrylate" herein includes both acrylic acid or acrylic ester and methacrylic acid or methacrylic ester.

The rubber elastomer-6-aromatic vinyl-vinyl cyanide copolymer is prepared by any method capable of polymerizing an aromatic vinyl monomer and a vinyl cyanide monomer in the presence of a rubber elastomer, sometimes or stepwise. can be manufactured. Therefore,
Suspension polymerization, emulsion polymerization, continuous bulk polymerization, and other methods may be appropriately selected and used depending on the type or condition of the given rubber elastic body. Specifically, for example, when the rubber elastic body is obtained as an emulsion, the monomer may be emulsion polymerized in the emulsion.

Especially when the rubber elastic body has ethylenically unsaturated bonds, the “technical” polymer consisting of a monomer such as an aromatic vinyl is added at least partially to the “backbone” polymer consisting of the rubber elastic body. It is often a graft polymer formed by bonding to.

The present invention targets rubber elastic body-aromatic vinyl-vinyl cyanide copolymers having a vinyl cyanide unit content of 40 to 90% by weight, preferably 40 to 75% by weight. That is. The contents of the rubber elastic body and the aromatic vinyl unit are respectively 3 to 30% by weight, preferably 5 to 25% by weight, and 5 to 57% by weight, preferably 10 to 55% by weight. Note that the content of vinyl cyanide units in the rubber elastic body-aromatic vinyl-vinyl cyanide copolymer does not include those derived from the rubber elastic body (if any).

(2) High nitrile AS resin As mentioned above, this tree J@ generally refers to an aromatic vinyl-vinyl cyanide copolymer in the present invention.

Specific examples of the aromatic vinyl monomer and vinyl cyanide monomer are the same as those described above for the high nitrile ABS resin. This resin also contains a small amount of comonomer copolymerized in addition to these two essential components, and specific examples of such comonomers include high nitrile ABS.
The same as described above for the resin.

The present invention provides such aromatic vinyl-vinyl cyanide J
Among the tffIa bodies, the content of vinyl cyanide units is 40
-90% by weight, preferably 40-75% by weight. Aromatic 1: nilflt
In Noa Hl;i, 60-10 weight 06 in subordinate z,
Preferably it is 60 to 25 weight 〇〇.

(2) Methacrylate polymer The thermal IIJ plastic resin III composition according to the present invention contains a methacrylate polymer as a processability improver.

A methacrylate polymer suitable for this purpose is a methacrylate polymer derived from methacrylic acid or an alkyl methacrylate (the number of carbon atoms in the alkyl group is about 1 to 5) at the -+-111 position of 25% by weight Oo'-1, preferably 40% by weight, 9° (1) A homopolymer or a polymer. When this polymer is a copolymer, the comonomer is:
can be any copolymerizable with methacrylate,
Specifically, there are acrylate monomers, tenka group vinyl (11-unit, vinyl cyanide Qt m-unit, and others. Specific examples include high nitrile ABS resin and /\initrile AS).
It is the same as described above for the resin (including the comonomer in the same resin).

IV v11 production ratio/'j11 production k:
By i'a Akira. ) Nor-fusible resin 1'11 composition is the above-mentioned high nitrile ABS resin or 1-1 nitrile A.
S Resin I C1F 1 part by weight is added to 0.5 to 10 parts by weight of methacrylate resin, preferably 0.
．． It is made by blending 5 to 3 times M parts.

Contains 0. If it is less than 5 parts by weight, there is no effect of preventing sticking to the screw. On the other hand, even if more than 3 parts by weight is added from the viewpoint of preventing screw winding, the effect will not increase much. Therefore, the upper limit][−)
Parts by weight are determined from the viewpoint of chemical resistance. In other words, the chemical resistance decreases as the parts by weight exceed [B].

The HIIJ plastic resin composition according to the present invention may optionally contain eight types of additives, such as a lubricant, a dispersant, an oxidation agent, etc., according to what is customary for thermal + iJ plastic resin compositions. /
J+1 agent, charge 1()1111i11, ultraviolet absorber, and blue agent can be added.

Among the Tsuno method and No. 17 for producing the products 4.11 and 17 of the present invention, the fF method and the h method, which allow uniform mixing of each component, are suitable.

Specifically, a high nitrile polymer and a methacrylate polymer, as well as additives and a blue agent if necessary, are mixed in a mixer such as an ordinary blender or Hennel mixer, and then mixed in a commonly used T11 extruder or two. Kneading may be carried out using a screw extruder, kneader-Banbury mixer, rolls, or the like.

When an extruder is used to produce these pellets, it was confirmed by disassembling the extruder after production that there was extremely little adhesion of molten resin to the screw and die parts. In the pellets, there is hardly any mixture of fired polymers.

■, Experimental Examples 1 to 4, Comparative Examples 1 to 2 Acrylonitrile (AN) 65% by weight as AS resin,
A suspension polymerization method containing 35% styrene (St) was added with 40% methyl methacrylate (MMA) and 96% α-methylstyrene (αMS) as methacrylate polymers.
) 50% by weight and ANIO heavy Q9o copolymer "Metablen H-601J (manufactured by Mitsubishi Rayon)" was
0.5, 1.0, '3.0.10.0 and 15.0 heavy mouth parts, and oxidation preventive 1F cutting and 0.1 part by weight of butylated hydroxytoluene (BHT) in a drum shape. The mixture was mixed in a kneading machine and melt-kneaded in a full-shaft extruder at 221:)°C to obtain pellets.

In addition, the time required to make pellets of 3 kg size from this blend was determined as A111. The northern part of the beret containing the burnt grains was sorted out using the inkstone judgment, and its ratio 8 was investigated.

On the other hand, add 22 (1
Thirty shots of each material were molded into a flat plate using an injection molding machine heated to .degree. C., and the weighing time was measured.

Further, the molded flat plate was immersed in methyl alcohol at room temperature for 17 hours, and changes in its appearance were determined with 1 visual inspection. The results were as shown in section 1k.

Regarding the color, the flat plate of Comparative Example 1 had a strong yellowish tinge as it contained countless carbides.

Examples 5-8, Comparative Examples 3-4 ABS resin: AN 65% by weight, butadiene 10
wt%, St 25% polymer composition and kiMA40
weight%, n-butyl acrylate 20% by weight, S[30
"Metablen P-700J (manufactured by Mitsubishi Rayon), which is a copolymer with a weight% of 10% and other components by weight of 0.0
．． 5.1.0.3.0.10.0. and 0.1 parts by weight of BHT as an antioxidant were mixed in a blender and melt-kneaded at 220° C. in a twin-screw extruder to obtain pellets.

This pellet was extruded into a film using a single-screw extruder equipped with a film die, and while being wound up with a take-up roll rotating at a constant speed, the thickness of the film was set to 711, and the runout 111 was set to 71P1.

Further, the film was immersed in methyl alcohol for 17 hours at room temperature, and the change in state was visually determined.

The results were as shown in Table 2.

From Tables 1 and 2, the following clearly depends on f.

(1) The composition of the present invention has good material penetration stability in extruders and injection molding machines, so
Bf: intercostal or short, 1; 1 quantity time and its 1; 10 hour runout in injection molding cycles! 1] is short and excellent (see Examples 1 to 4).

On the other hand, the composition not containing the meccrylate polymer is inferior in that the time required for pelletizing is long, +il'W time and its fluctuation is large (Comparative Example 1, 11i: ()).

(2) When the composition of the present invention is made into a film using an extruder, the film has a constant Ap1 constant value of 1ν,
The swing width is small and excellent (see Examples 5 to 8)
.

On the other hand, methacrylate! A composition that does not contain Ii
I"l of the film; the m constant value has a large fluctuation range and is inferior (comparative example 3).

(3) The composition of the present invention has excellent methyl alcohol resistance because its composition is appropriately selected (see Examples 1 to 8).

hs Compositions obtained outside the scope of the present invention have poor methyl alcohol properties (see Comparative Example 2).

1[ko11

Claims (1)

[Claims] Rubber elastic body containing 40 to 90% by weight of vinyl cyanide units-aromatic vinyl-vinyl cyanide copolymer and/or aromatic vinyl-vinyl cyanide copolymer containing 40 to 90% by weight of vinyl cyanide units 1. A thermoplastic resin composition comprising 0.5 to 10 parts by weight of a methacrylate polymer containing 25% by weight or more of methacrylate units per 100 parts by weight.