JPH0362853A - Polyphenylene sulfide-based resin composition - Google Patents

Abstract

PURPOSE:To obtain a polyphenylene sulfide-based resin composition suitable as various molding materials having improved compatibility and excellent mechanical strength by mixing a graft polymer having specific molecular structure as compatibilizer. CONSTITUTION:(A) Polyphenylene sulfide is mixed with (B) thermoplastic polymer (e.g. polystyrene) other than polyphenylene sulfide in a weight ratio of A/B=(5/95)-(95/5), preferably (20/80)-(80/20) and 100 pts.wt. resultant mixture is mixed with (C) 0.1-30 pts.wt., preferably 0.3-20 pts.wt. graft polymer derived from micromonomer method and composed of epoxy group-containing vinyl polymer as backbone component and a polymer highly compatible with thermoplastic resin blended to polyphenylene sulfide as branch component to afford the objective resin composition.

Description

Detailed Description of the Invention (a) Purpose of the Invention [Field of Industrial Application] The present invention provides a polyphenylene sulfide resin composition that can be used in a wide range of applications such as general consumption and industrial molding materials, electronic materials, and adhesives. The present invention relates to polyphenylene sulfide resin compositions that utilize polymer alloy techniques, which have recently attracted attention as a method for modifying resins.

[Conventional technology and its problems]

BACKGROUND OF THE INVENTION With the remarkable development of the polymer chemical industry in recent years, many polymer materials are being used in large quantities in daily life products, industrial products, vehicles, building materials, and the like.

Polyphenylene sulfide is a crystalline engineering plastic with excellent heat resistance, chemical resistance, moldability, etc. In recent years, demand has increased and prices have fallen, and it is predicted that polyphenylene sulfide will become one of the general-purpose engineering plastics in the future. By reinforcing with glass fiber, the heat resistance temperature has been improved to the level of thermosetting resin, and in addition, it has good molding fluidity, chemical resistance, and dimensional stability, so it has been put into practical use in recent years, especially as electrical/electronic parts and automobile parts. is progressing.

Disadvantages of boria and 1-nylene sulfide include low impact resistance, decreased rigidity at temperatures above 100°C, and poor heat resistance when not reinforced with glass fiber, etc. In order to improve these drawbacks, alloying with other resins, adding fillers, using additives, etc. are being actively studied.

In order to improve the physical properties of the resin through polymer blending, the resin to be mixed with polyphenylene sulfide may include elastomers such as ethylene copolymers and hydrogenated diene polymers,
Polyphenylene oxide, polycarbonate, polysulfone, polyamide, polyester, polyimide, and various polyamides and polyesters are used. Measures have been taken to improve compatibility by modifying the resin to be blended with epoxy groups or acid anhydride groups, and taking advantage of the reactivity of those reactive groups to polyphenylene sulfide. Ta.

Methods such as copolymerization or grafting have been used to introduce monomers containing reactive groups such as the above-mentioned epoxy groups into the resin blended with polyphenylene sulfide, but polyphenylene sulfide resins obtained by such methods The composition had a problem of high manufacturing cost.

On the other hand, if the compatibility of a polymer blend can be improved by adding a small amount of a compatibilizing agent as a third component, the production cost can be reduced, which is practically useful.

Block polymers and graft polymers having different types of polymer segments in the same molecule are said to be effective as compatibilizers. Therefore, if a block polymer or graft polymer having both a polar group-containing segment to obtain affinity with polyphenylene sulfide and a segment compatible with the other blended polymer in the molecule is used as a compatibilizer, , is expected to exhibit excellent effects.

It is difficult to industrially produce block polymers, and it is especially difficult to introduce monomers with polar groups, so it is preferable to use graft polymers, which are advantageous for industrial production, but conventional chain transfer methods , radiation grafting method,
In graft polymer production methods such as the polymer initiator method,
In general, the grafting rate is low, making it difficult to control the molecular weight and composition, and the types of polymers that can be synthesized are also limited.

(B) Structure of the Invention [Means for Solving the Problems] In view of the above-mentioned problems, the present inventors have conducted intensive studies to obtain a polyphenylene sulfide resin composition with excellent performance, and as a result, the inventors have developed a specific molecular structure. The graft polymer having
The present invention was completed based on the discovery that the present invention acts as an excellent compatibilizer in polyphenylene sulfide resin compositions.

That is, the present invention provides a polyphenylene sulfide resin composition comprising polyphenylene sulfide, a thermoplastic resin other than polyphenylene sulfide, and a graft polymer produced by a macromonomer method, wherein the graft polymer is a backbone comprising a vinyl polymer having an epoxy group. A polyphenylene sulfide resin composition is characterized in that it is composed of a component and a branch component consisting of a polymer having good compatibility with the thermoplastic resin, and furthermore, it is a graft polymer produced by a macromonomer method. Polyphenylene sulfide and the thermoplastic resin, the trunk component being a vinyl polymer having an epoxy group, and the branch components being a graft polymer that is a polymer having good compatibility with a thermoplastic resin other than the polyphenylene sulfide blended with the polyphenylene sulfide. It is a compatibilizing agent for

The present invention will be explained in more detail below.

[Graft polymer]

The graft polymer used in the present invention is produced by a macromonomer method, and contains a polymer segment having good compatibility with a thermoplastic resin (hereinafter referred to as a modifying resin) to be blended into polyphenylene sulfide (described later) as a branch component, and an epoxy group. It has a polymer segment containing as a main component.

The macromonomer used in the present invention is a high molecular weight monomer having a radically polymerizable group at one end of a vinyl polymer chain, and such macromonomer is copolymerized with one or more other vinyl monomers. A graft polymer obtained by such a method has a polymer segment derived from a macromonomer as a branch component and a vinyl monomer alone or copolymer segment as a main component. It has a structure and is called a macromonomer method graft polymer in boat fishing.

As mentioned above, the branch component of the graft polymer in the present invention is a polymer segment that has good compatibility with the modifying resin, and the monomers that should constitute the branch component are selected depending on the type of the modifying resin. be done.

Specifically, vinyl esters of organic acids such as vinyl acetate, styrene, styrene substitutes, vinylpyridine,
Vinyl aromatic compounds such as vinylnaphthalene, N-vinyl compounds such as (meth)acrylic esters, (meth)acrylonitrile, acrolein, N-vinylpyrrolidone and N-vinylcaprolactam, unsaturated acid anhydrides such as maleic anhydride, N-substituted male compounds such as N-phenylmaleimide and the like can be used. Preferably styrene, styrene substituted products, (meth)acrylic esters,
(meth)acrylonitrile, more preferably styrene, alkyl (meth)acrylate and acrylonitrile.

A polymer chain that is appropriately selected from the above monomers and has excellent compatibility with the modifying resin may be formed as a branch component.

Examples of combinations of modifying resins and compatible segments are as follows.

i) Polystyrene, high impact polystyrene, polyphenylene ether → polystyrene ii) Acrylonitrile/styrene copolymer resin, acrylonitrile/
Butadiene/styrene copolymer resin, polycarbonate → acrylonitrile/styrene copolymer or polymethyl methacrylate iii) Methacrylic resin, polyvinyl chloride, polyvinylidene fluoride - Polymer segment that becomes polymethyl methacrylate or acrylonitrile/styrene copolymer technology The molecular weight is 1000 to 20000 in number average molecular weight.
0 is preferable, and 2,000 to 100,000 are more preferable. If the number average molecular weight is less than 1,000, the anchor effect to the modifying resin will be insufficient and the compatibilizing effect will be small, which is undesirable. If it exceeds 200,000, the dissolution rate in polyphenylene sulfide and the modifying resin will decrease, and the kneading conditions is restricted.

On the other hand, the backbone component of the graft polymer is a polymer segment containing an epoxy group, and is formed from an epoxy group-containing vinyl monomer or a monomer mixture of it and other vinyl monomers.

As the epoxy group-containing vinyl monomer, glycidyl esters such as glycidyl methacrylate, glycidyl acrylate, glycidyl ethacrylate, and glycidyl itaconate, and glycidyl ethers such as allyl glycidyl ether and 2-methylallyl glycidyl ether are used. ,
Glycidyl methacrylate, glycidyl acrylate, and allyl glycidyl ether are preferably used, and glycidyl methacrylate is more preferably used.

When the trunk component is a copolymer containing an epoxy group-containing vinyl monomer unit, the monomers listed above may be used in combination as monomers for forming the branch components.

The molecular weight of the main component is 1000 to 2000 in number average molecular weight.
00 is preferable, and 2000 to 100000 is more preferable. If the number average molecular weight is less than 1,000, the reactivity to polyphenylene sulfide will decrease and the compatibilizing effect will be small.
If it exceeds 00,000, moldability decreases due to increased viscosity of polyphenylene sulfide.

The content of the epoxy group-containing vinyl monomer units in the graft polymer having the above-mentioned branch components and trunk components as constitutional units is 1 to 30% by weight based on the total amount of monomer units constituting the graft polymer. Preferably, 3 to 20% by weight is more preferable. If it is less than 1% by weight, the compatibilizing effect on polyphenylene sulfide is small, while if it exceeds 30% by weight, the anchoring effect of the compatible segment to the modifying resin tends to be insufficient.

The weight ratio of the branch component to the trunk component is preferably 5 to 80% by weight for the branch component and 20 to 95% by weight for the trunk component, and preferably 10 to 50% by weight for the branch component and 50 to 90% by weight for the trunk component. More preferred. If the branch component is less than 5% by weight, the anchoring effect on the modifying resin will be small, while if the trunk component is less than 20% by weight, the degree of reaction to polyphenylene sulfide will be low and the compatibility with polyphenylene sulfide will be poor. .

The molecular weight of the graft polymer is 2000 in number average molecular weight.
~300000 is preferred. If the number average molecular weight is less than 2,000, the molecular chain length of the polymer is too short and a sufficient compatibilizing effect cannot be obtained, and if it is more than 300,000, blending is required. In the case of a graft polymer with a main component of A macromonomer having a polystyrene as a polymer skeleton is obtained by reacting it with a vinyl polymerizable monomer having a glycidyl group in the molecule in the presence of a catalyst such as a polystyrene or a quaternary ammonium salt, and converting the macromonomer into glycidyl methacrylate. It can be produced by copolymerizing with styrene.

Examples of chain transfer agents having a carboxyl group in the molecule include mercaptoacetic acid, 3-mercaptopropionic acid, and 2-mercaptopropionic acid.
-Mercaptopropionic acid and the like are preferred, and as the vinyl polymerizable monomer having a glycidyl group in the molecule, glycidyl methacrylate (hereinafter abbreviated as GMA), glycidyl acrylate, allyl glycidyl ether, etc. are used, GMA is particularly preferred.

As a method for copolymerizing the macromonomer with GMA and the comonomer, any of the conventionally known methods of solution polymerization, bulk polymerization, emulsion polymerization, and suspension polymerization in the presence of a radical polymerization initiator can be used. good.

[Polyphenylene sulfide]

The polyphenylene sulfide in the present invention has the formula [I]
It is a polymer having 70 mol% or more of repeating units represented by; More preferably, it is a polymer having 90 mol% or more of the above units. A polymer containing less than 70 mol % of the above units does not exhibit the properties derived from the units, that is, the various properties unique to polyphenylene sulfide.

3 Examples of copolymer units that can form polyphenylene sulfide together with the above repeating units include units represented by the chemical formula shown below.

A copolymer type having the above copolymer unit and a unit represented by the above formula (1) The polyphenylene sulfide may be either a random copolymerization type or a block copolymerization type.

A general polymerization method for obtaining polyphenylene sulfide is to combine sodium sulfide and p-dichlorobenzene with N-
There are methods in which the reaction is carried out in an amide solvent such as vinylpyrrolidone or dimethylacetamide, or a sulfone solvent such as sulfolane.

In the above polymerization, in order to adjust the degree of polymerization of polyphenylene sulfide, an appropriate amount of an alkali metal carboxylate such as sodium acetate or lithium acetate may be added to the polymerization system.

The melt viscosity of polyphenylene sulfide in the present invention may be of a level suitable for obtaining a molded article, and specifically, it is preferably 100 to 10,000 poise.

[Modifying resin]

In the present invention, the thermoplastic resin that is mixed with polyphenylene sulfide to modify the polyphenylene sulfide, that is, the modifying resin, is preferably a thermoplastic resin that can improve impact resistance and heat resistance, which are disadvantages of polyphenylene sulfide.

Specifically, examples include polystyrene, rubber-modified polystyrene known as high-impact polystyrene, acrylonitrile/styrene copolymer, polymethyl methacrylate, polyvinyl chloride, polyphenylene oxide, polycarbonate, polysulfone, polyester, polyester, and polyfluoride. vinylidene, acrylonitrile/butadiene/styrene terpolymer C (hereinafter referred to as ABS resin), ABS
The rubber component of the resin is acrylic rubber, chlorinated polyethylene,
Generally AAS resin, AC3 resin, ABS, each substituted with ethylene/propylene/diene monomer copolymer rubber
Examples include graft copolymers called resins, fluororesins such as polytetrafluoroethylene, and silicone resins such as polydimethylsiloxane. These resins can be blended alone or with polyphenylene sulfide over 21 minutes.

6 More preferred modifying resins are polystyrene, polyphenylene oxide and ABS resin.

Next, the blending ratios of polyphenylene sulfide, graft polymer, and modifying resin will be described.

The preferred blending ratio of polyphenylene sulfide and modifying resin is polyphenylene sulfide/modifying resin = 5/95 to 9515, more preferably polyphenylene sulfide/modifying resin -20/80 to 8.
It is 0/20. If the proportion of the minor component is less than 5% by weight, the physical properties of the minor component will not be sufficiently reflected in the resin composition, which is not preferable.

Further, the preferred blending amount of the graft polymer is 0.1 to 30 parts by weight, more preferably 0.3 parts by weight per 100 parts by weight of the total of polyphenylene sulfide and thermoplastic resin.
~20 parts by weight. The amount of graft polymer added is 0.
If it is less than 1 part by weight, the compatibilizing effect will not be sufficiently achieved, while if it exceeds 30 parts by weight, the melt viscosity will increase and moldability will decrease.

Methods for kneading the above-mentioned components include, for example, methods using an extruder, kneader, open roll, etc., and methods for blending polyphenylene sulfide, graft polymers, and modifying resins include -blend blending method, polyphenylene sulfide, graft polymer, and modifying resin. Examples include a method in which a sulfide and a graft polymer are first blended, and then a modifying resin is blended, a method in which a modifying resin and a graft polymer are first blended, and then a polyphenylene sulfide is blended.

A preferred embodiment for obtaining the polyphenylene sulfide resin composition of the present invention is to mix the above three components using a Henschel mixer or the like, then further knead them while melting using an extruder, extrude them, and cut them into berent shapes. This is the way to do it.

The resin composition of the present invention also contains various additives normally used in polyphenylene sulfide resin compositions, such as plasticizers, antioxidants, stabilizers, inorganic fillers, reinforcing agents such as glass fiber, pigments, Dyes, modified products of butadiene-based elastomers, olefin-based elastomers, etc. with unsaturated acid anhydrides, catalysts that promote the reaction between epoxy groups and danno groups, and the like can be used.

[Effect]

The graft polymer in the present invention contains an epoxy group in the main component that can form a chemical bond with the mercap 1-group attached to the end of polyphenylene sulfide, so the graft polymer as a whole is compatible with the modifying resin. Even if it contains more monomer units with good properties, it shows extremely good compatibility with polyphenylene sulfide. As a result, the polyphenylene sulfide and the modifying resin are mixed extremely homogeneously through the graft polymer.

The present invention will be explained in more detail with reference to Reference Examples and Examples below. In addition, the percentage written on each side means % by weight, and the part written on each side means parts by weight.

Reference Example: In a glass flask equipped with a stirrer, reflux condenser, dropping funnel, and thermometer, add Karatsu water! 00 parts, 5χ aqueous solution of polyvinyl alcohol (Poval 420 manufactured by Kuraray ■) 4
1 part, calcium phosphate suspension (Nihon Kagaku Kogyo ■Production method - Pertite 10) 10 parts, 5χ aqueous solution of sodium dodecylhenzenesulfonate (Emar 2F manufactured by Kao ■) 0.2 parts
I prepared a section.

In the above dropping funnel, 30 parts of polystyrene macromonomer having a methacryloyl group at the end (macromonomer manufactured by Toagosei Kagaku Kogyo ■, AS-6), 60 parts of Stereph, GM
A solution containing 3.0 parts of AIO and 3.0 parts of AIBN was added, and the flask was heated to set the temperature of the internal liquid to BOoC, and then the solution in the dropping funnel was added dropwise over 1 minute. The mixture was kept at 80°C for 7 hours to complete the polymerization reaction.

After the reaction, the mixture was filtered and dried under reduced pressure to obtain 91 parts of a solid graft polymer. The average molecular weight in terms of polystyrene by GPC is Mn=22.000 Mw=180. It was OOO.

Examples 1 to 3 and Comparative Example 1 Commercially available polyphenylene sulfide resin (Asahi Glass AS)
AHI-PPS RG-40JA), a commercially available polyphenylene oxide resin (rubber-reinforced product), and the graft polymer prepared in Reference Example were triblended at the weight ratios shown in Table 1, and then a twin-screw extruder (29 m diameter
Melt blending was carried out at a resin temperature of 280°C using the following method (L/D=25).

The obtained resin composition was subjected to a tensile test (a test piece was prepared by press molding a pellet and then machined, and the tensile speed was measured at 10 m+/min).

In addition, the test piece was cooled in a dry ice-methanol bath and then crushed, and the fractured surface was observed using a scanning electron microscope. The results are shown in Table 1.

■ 2 (c) Effects of the invention In the present invention, due to the extremely excellent compatibilizing effect of the graft polymer used as a compatibilizer, polyphenylene sulfide, which is a resin with poor compatibility in nature, and the modifying resin can be separated into extremely small particles. As a result, the resin composition of the present invention has the properties of both polyphenylene sulfide and a modifying resin, and also has excellent mechanical strength. , suitable as various molding materials.

Claims (1)

[Scope of Claims] 1. A polyphenylene sulfide-based resin composition comprising polyphenylene sulfide, a thermoplastic resin other than polyphenylene sulfide, and a graft polymer produced by a macromonomer method, wherein the graft polymer is made of a vinyl polymer having an epoxy group. 1. A polyphenylene sulfide resin composition comprising a main component consisting of a trunk component consisting of a polymer having good compatibility with the thermoplastic resin and a branch component consisting of a polymer having good compatibility with the thermoplastic resin. 2. A graft polymer produced by the macromonomer method, the main component of which is a vinyl polymer having an epoxy group, and the branch components are polymers that are blended with polyphenylene sulfide and have good compatibility with thermoplastic resins other than polyphenylene sulfide. A compatibilizing agent for polyphenylene sulfide and the thermoplastic resin, comprising a certain graft polymer.