JPH03244657A - Polyester resin composition, and molded article molded therefrom - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyester resin composition and a molded article formed from the same, and more specifically, it has excellent impact resistance at low temperatures, heat resistance, In particular, the present invention provides a composition that has improved durability under high temperatures and is suitable for parts such as automobiles, electrical and electronic equipment, such as connector switches and relays.

[Conventional technology and its issues]

Crystalline thermoplastic polyester resins, such as polyalkylene terephthalate resins, have excellent mechanical properties, electrical properties, and other physical and chemical properties, and are easy to process, so they are used as engineering plastics in automobiles, electrical and electronics. It is used for a wide range of purposes such as parts.

However, with the expansion and diversification of applications, resins are often required to have even higher performance and special properties, and one of these characteristics is durability, especially long-term durability in high-temperature atmospheres. Stability of physical properties (long-term heat resistance) during use is increasingly required.

For example, in the automobile industry, due to safety needs, it is necessary to have excellent mechanical properties at low temperatures, especially flexibility, toughness such as impact resistance, and to maintain these physical properties even during long-term use at high temperatures. It is requested that it be done.

In order to meet such demands, methods have been proposed in which a thermoplastic elastomer such as a polycarbonate, an olefin polymer, or a rubbery polymer is blended with a thermoplastic polyester resin, and an epoxy resin, polycarbodiimide, etc. are further blended. There is. However, although the mechanical properties of polyester resins containing such elastomers and additives have been improved to a certain extent, they still suffer from surface peeling due to poor compatibility, and their long-term heat resistance is still insufficient. A solution was desperately needed.

[Means to solve the problem]

In view of such demands, the present inventors have developed excellent mechanical properties,
In particular, as a result of extensive research in order to obtain a polyester resin composition that does not impair impact resistance, moldability, etc., and that does not deteriorate in physical properties even after long-term use at high temperatures, the present invention has been developed. Reached.

That is, the present invention provides (A) a thermoplastic polyester resin (B) (i) ethylene (ii) an α-olefin having 3 or more carbon atoms or an unsaturated carboxylic acid ester (iii) a 3J unsaturated dicarboxylic acid or a derivative thereof
Modified ethylene copolymers 1 to 4 containing ijE as a constituent component
0% by weight (in the composition) (C) The present invention relates to a polyester resin composition comprising 0.01 to 10% by weight of an amide compound represented by the following general formula (I), and a molded article obtained by molding the same.

The constituent components of the composition of the present invention will be explained in detail below.

First, the thermoplastic polyester resin (A
) means polycondensation of a dicarboxylic acid compound and a dihydroxy compound, polycondensation of an oxycarboxylic acid compound, or these three.
It is a polyester obtained by polycondensation of a fraction mixture, and the present invention is effective on both homopolyester and copolyester.

Examples of dicarboxylic acid compounds used here include terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid,
These include known dicarboxylic acids such as diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylethanedicarboxylic acid, cyclohexane dicarboxylic acid, adipic acid, and sebacic acid, and alkyl, alkoxy, or halogen substituted products thereof. These dicarboxylic acid compounds can also be used in the polymerization in the form of derivatives capable of forming esters, for example lower alcohol esters such as dimethyl ester. Two or more types may be used.

Examples of dihydroxy compounds constituting the polyester (^) of the present invention include ethylene glycol, propylene glycol, butanediol, neopentyl glycol, hydroquinone, resorcinol, dihydroxyphenyl, naphthalene diol, dihydroxydiphenyl ether, cyclohexanediol, , 2-bis(4-hydroxyphenyl)propane, dihydroxy compounds such as jetoxylated bisphenol A, polyoxyalkylene glycols, and alkyl, alkoxy, or halogen-substituted products thereof, and may be used alone or in combination of two or more. I can do it.

Examples of oxycarboxylic acids include oxybenzoic acid, oxynaphthoic acid, diphenyleneoxycarboxylic acid, and alkyl, alkoxy, or halogen-substituted products thereof. Furthermore, derivatives of these compounds capable of forming esters can also be used. In the present invention, one or more of these compounds may be used.

In addition to these, polyesters having a branched or crosslinked structure may also be used in combination with a small amount of trifunctional monomers such as trimellitic acid, trimesic acid, pyromellitic acid, pentaerythritol, and trimethylolpropane.

In the present invention, the above compounds are used as monomer components,
Any thermoplastic polyester produced by polycondensation can be used as component (A)llii of the present invention, and may be used alone or in a mixture of two or more types, preferably polyalkylene terephthalate, more preferably polyalkylene terephthalate. Polybutylene terephthalate and copolymers mainly composed of polybutylene terephthalate are used.

Next, the modified ethylene copolymer (B) used in the composition of the present invention is (i) ethylene, (ii) α-olefin or unsaturated carboxylic acid ester having 3 or more carbon atoms, (ii)
i) at least 3 unsaturated dicarboxylic acids or derivatives thereof
It is obtained by polymerizing components.

Furthermore, the modified ethylene copolymer (B) in the present invention also means random terpolymers, block copolymers, graft copolymers, and mixtures thereof.

By using a copolymer consisting of the above three components, surface peeling caused by poor compatibility, which is a drawback of compositions containing thermoplastic elastomers such as rubbery polymers, which are usually used as impact modifiers, can be improved. Moreover, it has become possible to significantly improve flexibility at low temperatures and toughness such as impact resistance.

Examples of the α-olefin (ii) having 3 or more carbon atoms constituting such a copolymer include propylene, butene-1, hexene-11decene-1,4methylbutene-1,4-methylpentene-1, and the like. However, propylene or butene 1 is preferred.

The unsaturated carboxylic acid ester (ii) is an unsaturated carboxylic acid having 3 to 8 carbon atoms, such as an alkyl ester such as acrylic acid or methacrylic acid. Specific examples include methyl acrylate, acrylic acid, etc. Ethyl acid, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, etc. Ethyl acrylate or methyl methacrylate is particularly preferred.

Further, (iii) unsaturated dicarboxylic acids or derivatives thereof include maleic acid, fumaric acid, anhydrides or esters of these acids, and maleic anhydride is particularly preferred.

The modified ethylene copolymer (B) is preferably (i
) ethylene 50 to 96.9% by weight, (ii) α-olefin having 3 or more carbon atoms or unsaturated carboxylic acid ester 3 to
40% by weight, and (iii) unsaturated dicarboxylic acid or its derivative 0.1-10% by weight. If the unsaturated dicarboxylic acid or its derivative component is less than 0.1% by weight, the desired effect of the present invention will be small, while if it exceeds 10% by weight, undesirable results such as poor appearance due to yellowing and thermal stability will result. give.

Such modified ethylene copolymer (8) can be produced by any method. For example, a graft copolymer can be obtained by adding an unsaturated dicarboxylic acid or the like to a copolymer of ethylene and an α-olefin or an unsaturated carboxylic acid ester, and reacting the mixture at 120 to 250°C, preferably in the presence of a radical initiator. is obtained.

Alternatively, a radical initiator may be added to a mixture of ethylene, unsaturated carboxylic acid ester, unsaturated dicarboxylic acid, etc.
A terpolymer can be obtained by polymerizing under pressure of 00 to 2000 atm.

Also, certain types are available on the market.

The purpose of the present invention can be achieved using any modified copolymer, such as a terpolymer or a graft copolymer, and the modified copolymer may be selected depending on the various properties required.
In terms of overall quality, including moldability, mechanical properties, impact properties (especially at low temperatures), heat resistance, etc., copolymers of ethylene and α-olefins or unsaturated carboxylic acid esters, especially unsaturated dicarboxylic acids, A modified ethylene copolymer (8) obtained by graft polymerizing maleic anhydride is preferably used.

In the present invention, the blending amount of the modified ethylene copolymer (B) is 1 to 40% by weight, preferably 3 to 30% by weight based on the total amount of the composition. Here, if the blending amount of the modified ethylene copolymer (B) exceeds 40% by weight, the desirable properties originally possessed by the thermoplastic polyester resin in terms of rigidity, heat resistance, etc. of the resin composition will be impaired. On the other hand, if it is less than 1% by weight, the improvement in impact resistance is insufficient.

The composition of the present invention includes a specific amount of (A) a thermoplastic polyester resin, (B) a modified ethylene copolymer, and (C) an amide compound represented by general formula (I) as described above. By using these three components in combination, it has excellent flexibility and toughness such as impact resistance at low temperatures, no peeling phenomenon during molding, and is suitable for long-term use at high temperatures. This made it possible to maintain the initial excellent physical properties.

The amide compound (C) blended for this purpose is represented by the following general formula (■).

(C) The amide compound added as part a is (1)
Any compound having the structure shown by the formula is effective.

In the formula (1), R is an n-valent, that is, a di- to tetravalent organic group, such as an alkylene group having 1 to 10 carbon atoms, an arylene group having 6 to 12 carbon atoms, and a cycloalkylene group having 5 to 12 carbon atoms. ,
Examples include an aralkylene group having 8 to 20 carbon atoms. More specifically, the alkylene group includes methylene, ethylene, propylene, butylene, pentylene, hexamethylene, octamethylene, nonamethylene, decamethylene,
Examples include dimethylmethylene, and examples of arylene groups include phenylene, naphthylene, diphenylene, etc.
An example of the cycloalkylene group is cyclohexylene. Among these, -R- contains an aromatic group, particularly preferably a phenylene group.

In the formula, X is a C2 to CIO alkylene group or a substituent thereof, and examples of the substituent include an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms, and a cycloalkyl group having 5 to 12 carbon atoms. , an aralkyl group having 8 to 20 carbon atoms. More specifically, examples of alkyl groups include methyl, ethyl, propyl, butyl, pentyl, hexamethyl, octamethyl, nonamethyl, decamethyl, dimethylmethyl, etc., and examples of aryl groups include phenyl, naphthyl, diphenyl, etc. An example of cycloalkyl is cyclohexyl. Of these, X
As such, ethylene group and propylene group are preferable.

In the formula, Y is any one of -COOH, -DH, -3H, and -NH, and among these, -COOH and -OH are preferred.

Further, n is an integer of 2 to 4, preferably 2.

Specific examples of the amide compound (C) represented by general formula (I) include N, N'-bis(2-carboxyethyl)
Malonamide, N,N''-bis(2-carboxyethyl)succiamide, N,N'-bis(2-carboxyethyl)glutaramide, NIN'-bis(2-carboxyethyl)adipinamide, N,N'-bis (2-carboxyethyl>isophthalamide, N,N'-bis(2-
carboxyethyl) terephthalamide, N,N''-bis(3-carboxypropyl)malonamide, N,N'-bis(3-carboxypropyl)succiamide, N,N
'-bis(3-carboxypropyl)glutaramide,
N,N'-bis(3-carboxypropyl)adipinamide, N,N'-bis(3-carboxypropyl)isophthalamide, N,N'-bis(3-carboxypropyl>terephthalamide, N,N'- Bis(2-hydroxyethyl) malonamide, N,N'-bis(2-hydroxyethyl)succiamide, N,N'-bis(2-hydroxyethyl)cultaramide, N,N'-bis(2-hydroxyethyl)
-hydroxyethyl)adipinamide, N,N'-bis<2-hydroxyethyl>isophthalamide, N,N'
Bis(2-hydroxyethyl)terephthalamide, N,
N'-bis(3-hydroxypropyl)malonamide,
N,N'-bis(3-hydroxypropyl)succiamide, NIN'-bis(3-hydroxypropyl)glutaramide, N,N'-bis(3-hydroxypropyl)
Adipinamide, N, N'-bis(3-hydroxypropyl)isophthalamide, N, N'-bis(3-hydroxypropyl) terephthalamide, N, N',
N”-tris(2-hydroxyethyl)trimesinamide, 3,3°.

Examples include 5.5"-tetrakis(27hydroxyethylaminocarbonyl)biphenyl. These compounds may be used alone or in combination of two or more.

Among these compounds, N,N'-bis(2-carboxyethyl)isophthalamide, N,N'-bis(2-carboxyethyl)isophthalamide, N,N
'-Bis(3-carboxypropyl)isophthalamide, N,N'-bis(2-carboxyethyl)tere7thalamide, N,N'-bis(3-carboxypropyl)terephthalamide, N,N'-bis( 2-hydroxyethyl)isophthalamide, N,N'-bis(2-hydroxypropyl)isophthalamide, N,N'-bis(2
-hydroxyethyl)terephthalamide, N,N'-bis(2-hydroxypropyl)terephthalamide.

Such an amide compound is particularly effective when used in combination with the specific modified ethylene copolymer (B) of the present application to suppress a decrease in durability at high temperatures, which is a drawback thereof, and to maintain excellent initial physical properties.

The amount of the amide compound (C) added is 0.01 to 10% by weight (in the composition), preferably 0.01 to 5% by weight.
It is. Amide compounds have a strong affinity based on hydrogen bonding between the compounds or with polyester resin, so they have almost no sublimation and do not volatilize when heated, so they are effective even when added in extremely small amounts. 0
．． If it is less than 0.01% by weight, the effect is small. On the other hand, if the amount is too large, there will be a problem that the excellent physical properties of the polyester resin will be deteriorated.

Although the composition of the present invention is not essential, further effects can be obtained by using in combination one or more antioxidants such as hindered phenol, phosphorus, and thioether antioxidants.

Here, as hindered phenol antioxidants,
2.2'-methylene bis(4-methyl-6-4-butylphenol), hexamethylene glycol bis(3,5
-di-t-butyl-4-hydroxyhydrocinnamate), tetrakis[methylene (3,5-di-t-butyl-
4-Hydroxyhydrocinnamate>] Methane, triethylene glycol bis-3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate, 1
．． 3.5-) Listyl-2,4,6-) Lys(3,5-
';-t-butyl-4-hydroxybenzyl>benzene, n-tadecyl-3-(4°-hydroxy-3°,
5°-di-t-butylphenol)propionate, 4
．． 4°-methylenebis(2,6-di-t-butylphenol), 4,4'-butylidenebis(6-t-butyl-
3-methylphenol), 2.2'-thiodiethylbis[3,-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, distearyl-3,5-di-
t-butyl-4-hydroxybenzylphosphonate, 2
-t-butyl-6-(3-t-butyl-5-methyl-2-
Examples include hydroxybenzyl)-4-methylphenylacrylate.

Further, as the phosphorus antioxidant, organic phosphite-based and phosphonite-based compounds are suitable.

For example, it is represented by the following general formula (1), where R,,R, is an alkyl group,
They are selected from substituted alkyl groups, aryl groups, substituted aryl groups, and alkoxy groups, and may be the same or different. Among these, R1 and R2 are preferably an alkyl group, substituted alkyl group, or alkoxy group having 6 or more carbon atoms, or an aryl group or a substituted aryl group from the viewpoint of stability during processing.

Particularly preferred is the case where R, R2 is an aryl group or a substituted aryl group. Examples of these include phenyl group, naphthyl group, diphenyl group, and alkyl, hydroxy and/or alkoxy substituted products thereof. A specific example of a compound is bis(2,4-di-t-
butylphenyl) pentaerythritol diphosphite, bis(nonylphenyl) pentaerythritol diphosphite, 4-phenoxy-9-α-(4-hydroxyphenyl)-p-cumenyloxy-3, 5.8.10-
Examples include tetraoxa-4,9-diphosphaspiro[5,5]undecane.

Also, tetrakis(2,4-di-t-butylphenyl)-
Phosphonites such as 4,4'-biphenylene phosphonite and the like are also effective.

In addition, examples of thioether antioxidants include dilauryl thiodipropionate, simiristyl thiodipropionate, distearyl thiodipropionate, laurylstearyl thiodipropionate, and tetrakis[methylene-
Examples include 3-(dodecylthio)propionate comethane, dialkyl (C, . . . . )-3,3-thiodipropionate, and the like.

The amount of these antioxidants added is 0.05 to 5% by weight (in the composition), preferably 0.1 to 3% by weight.

The resin composition of the present invention can also be supplemented with a small amount of other thermoplastic resin as long as the purpose is not impaired. The other thermoplastic resin used here may be any thermoplastic resin that is stable at high temperatures.

For example, other polyolefin polymers, polyamides, A
BS, polyphenylene oxide, polyalkyl acrylate, polyacetal, polysulfone, polyether sulfone, polyetherimide, polyether ketone,
Examples include fluororesin. Moreover, two or more types of these thermoplastic resins can also be used as a mixture.

In order to further impart desired properties to the composition of the present invention according to its purpose, there are known substances other than those mentioned above that are generally added to thermoplastic resins, thermosetting resins, etc., i.e., stabilizers such as ultraviolet absorbers, Of course, it is also possible to blend antistatic agents, flame retardants, flame retardant aids, colorants such as dyes and pigments, lubricants, plasticizers, crystallization promoters, crystal nucleating agents, inorganic fillers, and the like.

Examples of inorganic fillers include glass fiber, carbon fiber, ceramic fiber, boron fiber, potassium titanate fiber, general inorganic fiber such as asbestos, calcium carbonate, highly dispersed silicate, alumina, aluminum hydroxide, talc, clay, and mica. , glass flakes, glass powder, glass peas, quartz powder, silica sand, wollastonite, carbon black, barium sulfate, calcined gypsum, silicon carbide, alumina, granular materials such as borosinirite and silicon nitride, plate-shaped inorganic materials Compound,
Includes whiskers, etc.

These inorganic fillers can be used singly or in combination of two or more, if necessary. A typical inorganic filler is glass beads, and it is often preferable to use them in combination with powdery or plate-like fillers.

There are no particular restrictions on the preparation of the composition of the present invention, and it can be easily prepared using known equipment and methods commonly used for conventional resin composition preparation methods.

For example, i) a method of mixing each component and then kneading and extruding it using an extruder to prepare pellets, followed by molding, 11
) - a method in which pellets with different compositions are first prepared, a predetermined amount of the pellets are mixed and then subjected to molding to obtain a molded product with the desired composition after molding, iii) a method in which one or more of each component is directly charged into a molding machine, etc. , any of them can be used. Further, it is a preferable method to mix and add a part of the resin component as a fine powder with other components in order to uniformly blend these components.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples.
The present invention is not limited to these.

The measurement method for evaluating physical properties shown in the following examples is as follows.

(2) Izot impact strength Notched izot impact strength was measured in accordance with ASTM D-256.

Measurement temperature: 23°C, 0°C ■ Tensile strength and elongation In accordance with ASTM D-638 (test piece ASTM type ■ type: thickness 1 mm), initial strength and elongation, and 12
The elongation was measured after heating at 0°C for 500 hours.

■ Surface condition of molded product The state of peeling on the surface of a molded test piece having a thin-walled part (particularly the thin-walled part of the molded product) was visually observed and evaluated on the following three scales.

○: Almost no peeling was observed.△: Peeling was observed. Various modified ethylene copolymers (B) and various amide compounds (C) shown in Table 1 were added and mixed in the proportions shown in Table 1, and a pellet-shaped composition was obtained using an extruder. Test pieces were prepared by injection molding using the pellets, and the above physical properties were evaluated.For comparison, we used samples in which the (B) component or (C) component was omitted, and also those in which the (B) component met the requirements of the present application. A copolymer of ethylene and ethyl acrylate was tested and evaluated in the same manner as in the examples.The results are also shown in Table 1.

Example 1O and Comparative Example 8 Tests and evaluations were conducted in the same manner as in Example 2, except that (A) llii in Example 2 was changed to a mixed polymer of polybutylene terephthalate and polyethylene terephthalate. The results are shown in Table 1. On the other hand, as a comparative example, a product in which component (C) was omitted was tested and evaluated in the same manner as in Example 20.

The results are also shown in Table 1.

〔Effect of the invention〕

As is clear from the above explanations and examples, the resin composition of the present invention has better heat resistance without impairing mechanical properties, moldability, etc., compared to conventional polyester resin compositions containing impact modifiers, etc. The object of the present invention is to provide a resin composition that has significantly improved stability, especially durability at high temperatures, and has excellent impact resistance at low temperatures.

As mentioned above, the composition of the present invention has little decrease in toughness due to thermal history and has excellent workability, so it can be used for mechanical materials and parts used for long periods in high-temperature environments in automobiles, electrical equipment, etc., such as connectors. Suitable for use in coil bobbins, switches, relays, etc.

Claims (1)

[Scope of Claims] 1 (A) Thermoplastic polyester resin (B) (i) Ethylene (ii) α-olefin or unsaturated carboxylic acid ester having 3 or more carbon atoms (iii) 3 unsaturated dicarboxylic acids or derivatives thereof Modified ethylene copolymer containing 1 to 40% by weight of
(In the composition) (C) The following general formula (I) ▲ Numerical formulas, chemical formulas, tables, etc. are included ▼ (I) (R represents an n-valent organic group, and X is an alkylene group of C_2 to C_1_0 or its substituted product) , Y is -COOH, -OH
, -SH, -NH_2, and n represents an integer of 2 to 4. ) A polyester resin composition comprising 0.01 to 10% by weight (in the composition) of an amide compound represented by: 2 The modified ethylene copolymer of component (B) is a copolymer of (i) ethylene and (ii) an α-olefin having 3 or more carbon atoms or an unsaturated carboxylic acid ester, and (iii) an unsaturated dicarboxylic acid or The polyester resin composition according to claim 1, which is grafted with a derivative thereof. 3 Constituting the modified ethylene copolymer (B) (iii)
3. The polyester resin composition according to claim 1, wherein the unsaturated dicarboxylic acid or its derivative is maleic anhydride. 4. The polyester resin composition according to claim 1, wherein R in formula (I) representing an amide compound (C) contains an aromatic group. 5 (C) Claim 1 in which X in formula (I) representing an amide compound is ethylene or propylene or a substituted product thereof.
The polyester resin composition according to any one of items 4 to 4. 6 (C) Y in formula (I) representing an amide compound is -C
The polyester resin composition according to any one of claims 1 to 5, which is OOH or -OH. 7. The polyester resin composition according to any one of claims 1 to 6, wherein the thermoplastic polyester resin (A) is a resin mainly composed of polybutylene terephthalate. 8. A molded article obtained by molding the polyester resin composition according to any one of claims 1 to 7.