JPH05170907A - Production of carboxyl group-containing polyphenylene sulfide - Google Patents

Abstract

(57) [Summary] [Structure] Polyphenylene sulfide and a modifier (for example, 4,4'-dithiodi (n-butyric acid)) selected from compounds having simultaneously a carboxyl group and a mercapto group or a disulfide group in the molecule are melted. Alternatively, they are reacted in a solution to produce a carboxy group-containing polyphenylene sulfide. According to the present invention, a carboxy group-containing polyphenylene sulfide can be easily produced without deterioration of the polyphenylene sulfide. The carboxyl group-containing polyphenylene sulfide of the present invention contains a highly reactive carboxyl group, and it is expected that a graft reaction with another resin or the like will be made by utilizing the reactivity.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a carboxyl group-containing polyphenylene sulfide obtained by modifying a polyphenylene sulfide molecule with a modifier selected from compounds having a carboxyl group and a mercapto group or a disulfide group. The carboxyl group-containing polyphenylene sulfide of the present invention reacts with a functional group of a blended resin when blended with another resin, for example, polybutylene terephthalate, polyamide, polypropylene having a polar group, or polyphenylene ether, as compared with an unfunctionalized polyphenylene sulfide. However, the compatibility between resins is increased, and a resin product having high solvent resistance, heat resistance, and mechanical properties is provided.

Therefore, this carboxyl group-containing polyphenylene sulfide is useful as a modifier for polyphenylene sulfide and as a compatibilizer precursor for polyphenylene sulfide and other resins. In addition, this compound is useful as a precursor for polyphenylene sulfide graft or block copolymers.

[0003]

2. Description of the Related Art Polyphenylene sulfide (hereinafter PPS)
May be abbreviated as "), and is known as a high-melting-point heat-resistant resin having excellent fluidity, organic solvent resistance, electrical characteristics, flame retardancy, and the like. However, when used as a molding material, there is a drawback that the degree of polymerization is low and the extrusion stability and molding stability are poor.
Further, since the glass transition temperature is not so high, the rigidity at high temperature is largely reduced. Therefore, performance improvement has been carried out by compounding with inorganic fillers such as glass fiber, carbon fiber, talc, silica, etc., but in this case, the appearance of the molded product is deteriorated, and warpage is likely to occur in the molded product. There is a problem.

Blending with polyolefins and other engineering plastics such as polyphenylene ethers, polybutylene terephthalates, polyamides, polyolefins etc. has been carried out with the aim of remedying these drawbacks. However, in these blends, both polymers are inherently poorly compatible. As a result, the resulting resin product is brittle, has a high mechanical strength,
The impact strength decreases, and it becomes unusable for practical use.

For example, polyphenylene ether (hereinafter P
There is disclosed a technique for improving the moldability of PPE by blending PPS with PE (sometimes abbreviated as PE) (JP-A-56-34032). However, although the molding processability is improved, the compatibility between PPE and PPS is inherently poor, and such a simple blend system has poor affinity at the interface, and phase separation occurs during molding, resulting in excellent mechanical strength. No composition is obtained.

For this reason, some techniques for improving the compatibility of the two have been proposed. For example, a method of blending an epoxy resin with a blend of PPS and PPE (JP-A-59-59).
164360 and 59-2113758), and a method of blending a styrene-based polymer having an epoxy group (JP-A-2-86652 and 213361). In addition, by introducing a functional group into PPE, modified P
As PE, it has been proposed to improve the miscibility with PPS. JP-A-64-36645 and JP-A-2-3
No. 6261 uses acid-modified PPE by melt-kneading a compound having an ethylenically unsaturated bond and an acid anhydride in the molecule, specifically maleic anhydride and PPE.
However, the mechanical strength of the resin composition obtained here is still insufficient because PPS has no reactive functional group.

In polymer blends, a graft or block copolymer of both polymers is commonly used as a compatibilizer for the polymer blend. However, since polyphenylene sulfide does not have a functional group in the molecule, the reaction at the time of blending PPS with a resin having another functional group (for example, polyamide, polyester, etc.) is
I can hardly expect it.

[0008] Therefore, for the purpose of introducing a functional group into PPS, JP-A-3-502474 discloses that an aromatic disulfide having a functional group is used as a modifier to produce a PPS containing an amino group or a carboxyl group. The method of doing is disclosed. However, a decrease in the molecular weight of PPS occurs,
It gives only very brittle modified PPS. Therefore, there is a continuing need to develop techniques for producing PPS containing functional groups in a relatively simple manner.

[0009]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a functionalized PPS having extremely excellent miscibility with polyphenylene ether, polyolefin, polyester and polyamide, specifically, a carboxyl group-containing polyphenylene sulfide. It aims at providing the method of manufacturing.

[0010]

The present invention provides a polyphenylene sulfide and a mercapto compound represented by the general formula (I).

[0011]

[Image Omitted] HS-R ¹ -COOR ² (I)

(In the formula, R ¹ represents an aliphatic or alicyclic residue having 1 to 10 carbon atoms. R ² represents a hydrogen atom or 1 carbon atom.
It represents a hydrocarbon or alkali metal atom of -10. ) Or a disulfide compound represented by the general formula (II)

[0013]

Embedded image R ² OOC-R ¹ —S—S—R ¹ —COOR ² (II)

(In the formula, R ¹ represents an aliphatic or alicyclic residue having 1 to 10 carbon atoms. R ² represents a hydrogen atom or 1 carbon atom.
It represents a hydrocarbon or alkali metal atom of -10. The present invention provides a method for producing a carboxyl group-containing polyphenylene sulfide, which comprises reacting <Polyphenylene sulfide> PPS used in the present invention
Is the general formula (III)

[0015]

[Chemical 5]

A crystalline resin containing a repeating unit represented by as a main constituent element. In the present invention, PPS comprising the above repeating unit, or containing 80% by mole or more, more preferably 90% by mole or more as a main component of the PPS, the copolymer with the following repeating units has physical properties such as heat resistance. It is preferable from the above point.

When substantially all the constituents of PPS do not consist of the repeating unit represented by the above formula (III), the rest (for example, up to 20 mol%) is copolymerizable, for example, as shown below. It is possible to satisfy any one of the components composed of the repeating unit, or two or more kinds.

[0018]

[Chemical 6]

[0019]

[Chemical 7]

[0020]

[Chemical 8]

[0021]

[Chemical 9]

[0022]

[Chemical 10]

[0023]

[Chemical 11]

(In the formula, Y is an alkyl group having 1 to 8 carbon atoms,
(A phenyl group, an alkoxy group, preferably a lower alkyl group) The PPS used in the reaction in the present invention preferably has a substantially linear structure from the viewpoint of the physical properties of the molded product. In the range that does not substantially reduce this physical property,
For example, a polymerized cross-linked product obtained by using an effective amount of a cross-linking agent (for example, trihalobenzene) at the time of polymerization, or a heat-cross-linked product obtained by cross-linking a polymer by heat treatment in the presence of oxygen can be used.

This PPS has a melt viscosity at 300 ° C. of 1
00-100,000 poise, preferably 500-5
10,000 poise, more preferably 500 to 20,
It is preferably in the range of 000 poise. Melt viscosity is 10
When it is less than 0 poise, the fluidity is too high and molding is difficult, which is not preferable. Further, even if the melt viscosity exceeds 100,000 poise, the fluidity is too low, and molding is difficult.

This PPS can be produced by any method as long as it does not violate the object of the present invention, but a preferable PPS satisfying the above conditions is disclosed in, for example, Japanese Patent Publication No. 45-3368. For example, a method for producing a polymer having a relatively small molecular weight, a method for producing a linear polymer having a relatively high molecular weight as disclosed in Japanese Patent Publication No. 52-12240, or heating a low molecular weight polymer in the presence of oxygen. According to the method for obtaining a crosslinked product, or by adding necessary modifications to these,
It can be manufactured. In addition, PPS can be treated with hot water or the like, if necessary, such as when using a fibrous filler.

<Modifier> The modifier to be reacted with PPS is
A compound having a carboxyl group derivative in the molecule, that is, a carboxylic acid, a carboxylic acid alkyl ester, a carboxylic acid alkali metal salt and a mercapto group or a disulfide group at the same time, which is represented by the above-mentioned general formula (I) and general formula (II). It is a compound. The alkyl group of the derivative of the carboxyl group is a methyl group, an ethyl group, a propyl group,
A butyl group is preferred. Examples of the alkali metal include lithium, sodium and potassium, with sodium being particularly preferable. Specific examples of the modifier include thiomalic acid, 4,4'-dithiodi (n-butyric acid), dithiodiacetic acid, 2,2'-dithiodipropionic acid, 3,3'-dithiodipropionic acid, mercaptoacetic acid. , 2-mercaptopropionic acid, mercaptovaleric acid and their alkyl esters, alkali metal salts and the like. Particularly preferred are thiomalic acid, 4,4'-dithiodi (n-butyric acid) and their carboxyl group derivatives.

<Carboxyl Group-Containing PPS> The carboxyl group-containing PPS can be easily produced by reacting a modifier with PPS in a molten state or in an organic solvent. The carboxyl group-containing PPS is obtained by combining the PPS and the modifier with PP.
PPS in an organic solvent in which S is soluble or partially soluble
And a modifier (0.1 to 100 parts by weight, preferably 1 to 20 parts by weight with respect to PPS) at 170 ° C to 300 ° C,
It can be easily produced by reacting.

The organic solvent used here is the raw material P
Although it is desirable that PS can be dissolved, an organic solvent that can partially swell PPS can also be used.
Specifically, aromatic solvents such as diphenyl, toluene and xylene, halogenated aromatic solvents such as chlorobenzene, dichlorobenzene and chloronaphthalene, N-methyl-2-
Examples include aprotic polar solvents such as pyrrolidone, dimethylimidazolidinone, dimethylacetamide, and sulfolane.

Furthermore, the carboxyl group-containing PP of the present invention
S can also be produced by the following melting reaction. For example, the carboxyl group-containing PPS may contain a modifier for the PPS in an amount of 0.01 to 20 parts by weight, preferably 0.1% by weight.
After mixing 1 to 10 parts by weight, 1 using an extruder and a kneader
In the temperature range of 50 to 350 ° C, preferably 280 ° C to 3
It is manufactured by melt-kneading in the temperature range of 40 ° C.

[0031]

EXAMPLES The present invention will be described in detail below with reference to examples. Polyphenylene sulfide is P made by Topren Co.
PS (Product name: Topren T-7 or Topren T-
1) was used. High temperature GPC measurement is Senshu Science
VHT-GPC 7000 (trade name) was used, the column temperature was 210 ° C., and the mobile phase was 1-chloronaphthalene.

Examples 1 to 2 To 100 parts by weight of polyphenylene sulfide (Toprene T-7; trade name; Mn2950; Mw44900), 1 part by weight of the modifier shown in Table 1 was added and uniformly mixed.
It was melt-kneaded with a twin-screw extruder at a temperature of 310 ° C. to form a strand, which was then pelletized. Almost no increase in the melt flow value was observed. As a result of GPC measurement, almost no decrease in the molecular weight of PPS was observed before and after denaturation. 0.5 g of the obtained modified PPS was added to 1-chloronaphthalene 2
It was dissolved in 0 ml at 220 ° C., and after cooling, 30 ml of acetone was added to cause precipitation. The obtained polymer was separated by filtration and dried, and then a press sheet was prepared, and FT-IR was measured. As a result, absorption attributed to the ketone of the carboxyl group was observed at the position shown in Table 1.

Comparative Example 1 PPS was modified in the same manner as in Example 1 except that aromatic disulfide 4,4'-bis (4-carboxyphthalimidophenyl) disulfide was used as a modifier. The carboxyl group-containing PPS obtained had an increased melt flow value and gave brittle strands. (High temperature GPC
Measurement result: Mn; 1,940. Mw; 16,900
0. )

[0034]

[Table 1]

Examples 3 to 4 Polyphenylene sulfide (Toprene T-1 manufactured by Topren Co., Ltd .; trade name; Mn2,010; Mw19,8)
00) and 0.5 g of the modifier shown in Table 2 were heated with stirring at 100 ° C. for 7 hours together with 100 ml of the organic solvent shown in Table 2. The solution was cooled, the precipitated polymer was filtered, washed with methanol, and dried by heating at 100 ° C. under reduced pressure. As a result of measuring FT-IR in the same manner as in Example 1, absorption attributed to the ketone of the carboxyl group was observed at the position shown in Table 2. As a result of GPC measurement, almost no change in molecular weight before and after denaturation was observed.

[0036]

[Table 2]

[0037]

By using the method of the present invention, carboxyl group-containing PPS can be produced by a simple method without deterioration of PPS as shown in Examples. The carboxyl group-containing PPS of the present invention contains a highly reactive carboxyl group, and it is expected that the PPS will be utilized for applications such as a compatibilizer precursor for polymer alloys by utilizing its reactivity.

[Brief description of drawings]

1 is a carboxyl group-containing PPS obtained in Example 2.
The infrared absorption spectrum of (press sheet) is shown. 173
Absorption of carboxylic acid is observed at 5 cm -1.

Claims (1)

[Claims] 1. A polyphenylene sulfide and a mercapto compound represented by the general formula (I): embedded image HS-R ¹ —COOR ² (I) (wherein R ¹ is an aliphatic group having 1 to 10 carbon atoms or Represents an alicyclic residue, R ² represents a hydrogen atom, a hydrocarbon having 1 to 10 carbon atoms or an alkali metal atom) or a disulfide compound represented by the general formula (II): R ² OOC- R ¹ -S-S-R ¹ -COOR ² (II) (In the formula, R ¹ represents an aliphatic or alicyclic residue having 1 to 10 carbon atoms. R ² represents a hydrogen atom or 1 carbon atom. 10 represents a hydrocarbon or an alkali metal atom of 10), and a method for producing a carboxyl group-containing polyphenylene sulfide.