JP2793385B2 - Polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition comprising a specific aromatic polyester resin and an olefin copolymer resin, which has excellent surface properties and excellent mechanical properties.

[0002]

2. Description of the Related Art Aromatic polyester resins and polyolefin resins are both thermoplastic resins having excellent moldability, each having a certain level of excellent mechanical and electrical properties and the like. Is used in a very wide range of fields. However, with the expansion of the application field, the required performance of the resin tends to be more and more advanced. As such a demand, aromatic polyester resin often requires higher toughness, impact resistance and alkali resistance. On the other hand, olefin resins represented by polyethylene, polypropylene and the like are generally lightweight, excellent in chemical resistance and flexible, but lack strength and rigidity, and their applications are often limited. In addition, both resins alone have poor affinity, and there is a problem in composite processing using both resins, for example, a laminated film formed by co-extrusion of both resins, or laminated blow molding due to lack of adhesiveness. As a means for solving such a problem, by blending the two uniformly, defects in their physical properties can be compensated for, and the fusion property and adhesion can be improved, and the improvement of composite workability can be expected. However, aromatic polyester resins , especially crystalline, are easy to mold and have excellent mechanical properties.
Polybutylene terephthalate (hereinafter referred to as PBT)
F) Even if the polyolefin resin is blended with the polyester and melt-kneaded, the compatibility of the two resins is poor and they are not evenly dispersed. In particular, injection molded products have a layered structure near the surface layer, and the surface layer peeling phenomenon appears strongly and mechanical properties And have no practical value. In an attempt to improve the compatibility between the polyester resin and the polyolefin resin and obtain a uniform dispersion state, the compatibility with the polyester resin is improved by using a modified polyolefin-based copolymer in which another copolymerization component is introduced into the polyolefin-based resin. Although many attempts to improve the physical properties have been proposed and the effect is recognized to some extent,
Depending on the purpose, particularly in the case of a PBT-based polyester, it is still not sufficient, and it is often required to further improve dispersibility and physical properties. The present invention solves the drawbacks due to the poor dispersibility of both components when the PBT-based polyester resin and the polyolefin-based resin are blended, and provides an excellent dispersion state. It is an object of the present invention to provide a composition having excellent surface properties, excellent physical properties, excellent adhesiveness, and particularly improved composite workability.

[0003]

Means for Solving the Problems In view of the above problems, the present inventors have conducted intensive studies on the improvement of the dispersion form in a polymer blend of a PBT-based polyester resin and a polyolefin-based resin, and as a result, have found that a specific sulfonic acid metal salt has been obtained. By using the PBT-based polyester resin (A) into which the units have been introduced, a composition having further improved dispersibility of both resins, having a smooth molding surface without surface delamination, and having excellent mechanical properties can be obtained. The inventors have found that the present invention can be obtained, and arrived at the present invention. That is, the present invention relates to (A) a terephthalic acid or its ester form
An aromatic dicarboxylic acid or an ester-forming derivative thereof having a synthetic derivative as a main component ; b 1,4-butanediol;
A polycondensation reaction of a diol compound or an ester-forming derivative thereof as an ingredient and an ester-forming compound containing a metal sulfonic acid salt represented by the following general formula (I) and / or (II): resulting sulfonic acid metal salt-containing polybutylene terephthalate-based port Riesuteru copolymer resin component (a), relative to the sum of (B) and (C) 2
(A), (B) and (B) as the component (B), an olefin-based copolymer obtained by copolymerizing at least one kind of an α, β-unsaturated carboxylic acid or a derivative thereof, vinyl alcohol or an ester thereof. 2 to 98% by weight based on the sum of C) Polyester containing 0 to 96% by weight of aromatic polyester resin as component (C) based on the sum of resin components (A), (B) and (C) It relates to a resin composition.

(XOCO) _m -Ar- (SO ₃ M) _n (I) (HORO) _m -Ar- (SO ₃ M) _n (II) (where -Ar- is a benzene ring or a naphthalene ring, X
Is a hydrogen atom or a lower alkyl group. m and n are
1 or 2 respectively, M is lithium, sodium, potassium
If n is 2, the same alkali metal
May be. R is -CH ₂ CH _2- , -CH (CH ₃ ) CH _2- , -CH _{2
CH (CH 3) -, -} CH 2 CH 2 OCH 2 CH 2 - 2 divalent radical der selected from
You. ) Will be described below each of the components used in the present invention. Specific sulfonate-containing PBT used in the present invention
System polyester resin (A), in the presence of an ester forming monomer c containing such later sulfonate, tele
A dicarboxylic acid or an ester-forming derivative thereof having phthalic acid or an ester-forming derivative thereof as a main component ;
PBT produced by polycondensation of a diol containing 4-butanediol as a main component or its ester-forming derivative b
It is a system polyester resin. That is, the dicarboxylic acid of the monomer a constituting the component (A) or an ester-forming derivative thereof is terephthalic acid or a lower alcohol ester thereof.
Teru, etc., and a small amount of isophthalic acid, 2,
6 or 2,7-naphthalenedicarboxylic acid, and also 4,
One or two or more of 4-diphenyldicarboxylic acid, adipic acid, sebacic acid, cyclohexanedicarboxylic acid or lower alcohol esters thereof may be used in combination. Next, as a diol component of the monomer b constituting the component (A), 1,4-butanediol is mainly used.
And, optionally a small amount of ethylene glycol, 1,3-propanediol Lumpur, 1, 4-cyclohexane dimethanol, polyoxyethylene glycol, polyoxypropylene glycol, diol or ester-forming derivatives thereof such as polyoxybutylene glycol One or two
More than one species may be used in combination . The component (A) is, as a part of the constituent monomer a or b , a trifunctional or higher functional ester-forming compound, such as trimesic acid, trimellitic acid, pyromellitic acid, or an ester-forming derivative thereof; May be a polyester copolymer having a crosslinked or branched structure produced by using a small amount of glycerin, trimethylolpropane, pentaerythritol, or the like. Used in the present invention (A) a polyester component, PBT polyester with a further copolymerization or certain metal sulfonate salt polycondensation by adding ester-forming compound having a specific sulfonic acid metal salt as a reaction component c It is. The monomer component c added for such purpose is an aromatic carboxylic acid having a sulfonic acid metal salt represented by the following general formula (I) and / or (II) or a lower alkyl ester or alcohol thereof. (XOCO) _m -Ar- (SO ₃ M) _n (I) (HORO) _m -Ar- (SO ₃ M) _n (II) (where -Ar- is a benzene ring or a naphthalene ring, and X
Is a hydrogen atom or a lower alkyl group. m and n are each 1 or 2, and M is an alkali metal selected from lithium, sodium and potassium. When n is 2, they may be the same or different. R is -CH ₂ CH _2- , -CH (CH ₃ ) CH _2- , -CH _{2
CH (CH 3) -, -C} H 2 CH 2 OCH 2 CH 2 - is a more selected divalent groups. ) The monomer c may be added and mixed simultaneously with the components a and b in the polycondensation reaction of the polyester (A),
Any stage may be used as long as it is before the completion of the polycondensation reaction, but the preceding stage is preferred as much as possible, and particularly preferred are a,
It is preferably added before the esterification reaction or transesterification reaction with the component b. When the sulfonic acid metal salt-containing compound c is m = 1 in the formula (I) or (II), since the esterification functional group is one, it is introduced as a terminal group of the PBT-based polyester (A). When m = 2, a copolymer randomly introduced into the main chain as a copolymer component is obtained. P of component (A) in the present invention
The BT-based polyester may be any one of them. Further, as the c component monomer, two or more types represented by the formulas (I) and (II) may be used in combination. The amount of the c unit constituting the PBT-based polyester (A) is based on all the ester constituting units.
It is 0.01 to 15 mol%, preferably 0.1 to 10 mol%. The content of the c unit in the polyester (A) can be adjusted by adjusting the amount of the monomer of the formula (I) or (II). The amount of the unit c in the component (A) depends on the purpose, and may be determined in the following (B),
The optimum properties of the composition can be obtained by appropriately changing the component (C) within the above range depending on the type and amount of the component. However, the amount of the unit c in the component (A) is 0.01
If it is less than 15 mol%, the effect of improving the compatibility and dispersibility, which is the main object of the present invention, cannot be obtained, and if it is more than 15 mol%, a polymer having a high degree of polymerization cannot be obtained. This also causes trouble and is not preferred. The most typical PBT-based polyester as the component (A) includes an ester-forming unit of the formula (I) or (II) having a sodium sulfonic acid salt.
Polybutylene terephthalate, butylene terephthalate
A PBT-based copolymer which mainly contains tallate and also contains a small amount of an auxiliary unit such as isophthalate, cyclohexane dimethylene terephthalate, butylene-2,6-naphthalate or butylene-2,7-naphthalate may be used.
No.

The polyolefin resin (B) used in the present invention is an olefin copolymer obtained by copolymerizing at least one of α, β-unsaturated carboxylic acid or its derivative, vinyl alcohol and its ester. As the olefin constituting such an olefin-based copolymer, ethylene,
Or an α-olefin having 3 or more carbon atoms such as propylene, butene-1, hexene-1,4-methylbutene-
It comprises one or more of 1,4-methylpentene-1 and the like, particularly propylene and butene-1. The α, β-unsaturated carboxylic acid or a derivative thereof as a copolymer component includes, for example, acrylic acid, methacrylic acid, ethacrylic acid, maleic acid,
Examples thereof include fumaric acid or a metal salt thereof (a metal belonging to Group 1 or 2), an alkyl ester, a glycidyl ester, an anhydride, and an imide. Further, an ester thereof such as vinyl alcohol or vinyl acetate may be used. One or more of such copolymerization components are introduced into a polyolefin-based polymer as a copolymerization (including graft copolymerization and block copolymerization) component to constitute the component (B). (B)
As a component, these are mainly used, and other vinyl monomers (eg, styrene, butadiene, acrylonitrile, etc.)
May be a polyolefin copolymer or a polyolefin elastomer obtained by further copolymerizing a copolymer, a copolymer containing a small amount of a crosslinking agent or another modifier, a terpolymer, a block polymer, or a molecule having not only a linear but also a branched or crosslinked structure. You may have. The degree of polymerization and the like are not particularly limited as long as they have moldability. Such olefin copolymers can be used in combination of two or more. Particularly preferred olefin copolymers (B) include metal salt copolymers of ethylene-methacrylic acid or acrylic acid (metals such as lithium, sodium, potassium, calcium, magnesium, zinc, etc.), ethylene-methacrylic acid or acrylic An acid ester copolymer, a propylene-maleic acid or maleic anhydride copolymer, an ethylene-vinyl acetate copolymer or a saponified product thereof can be used.

Next, the polyester composition of the present invention is not necessarily an essential component, but further contains a metal sulfonic acid salt.
Apart from the PBT-based polyester (A), a general polyester resin (C) can be blended. As the polyester resin of the component (C) used herein, the polyester formed by only the monomers a and b in the constitution of the component (A) is most preferable , and typical examples thereof include:
Although it is Po polybutylene terephthalate resin, polyether
Chi terephthalate) resins, poly (cyclohexane dimethylene terephthalate resin, or copolymer resin which these mainly, or thermoplastic elastomer obtained by copolymerizing a high molecular weight of the oxyalkylene glycols, furthermore may be a liquid crystalline polyester resin Or a mixture of these
May be.

[0007] In the composition of the present invention, (A), (B)
And the proportion of the component (C) is 2 to 98% by weight of (A) and 2 (B), with the sum of (A), (B) and (C) being 100 (weight).
To 98% by weight, and (C) to 0 to 96% by weight. In particular, the sum of the components (A) and (C) is preferably 5 to 95% by weight, and the component (B) is preferably 5 to 95% by weight. If the amount of the component (B) is too small, the effect of improving the mechanical properties such as the impact resistance of the polyester resin composition cannot be obtained. If the amount is too large, the inherent properties of the polyester resin are lost, and the rigidity is particularly reduced. Not preferred. Particularly preferred amount of component (B) is 5 to 5.
50% by weight. The ratio of the component (A) to the component (C) depends on the content of the sulfonic acid metal salt unit in the component (A), but at least the component (A) is preferably at least 2% by weight based on the resin component. Is required to be 5% by weight or more for improving dispersibility. When the content of the sulfonic acid metal salt unit in the component (A) is relatively low within the above range, it is preferable to reduce the amount of the component (C). When the content of the sulfonic acid metal salt unit is relatively large within the above range, the component (A) is reduced,
It is possible to increase the amount of the component (C), which is preferable. In this case, the molecular weight of the component (A) may be relatively low.

As described above, simply melt-kneading a general aromatic polyester resin (C), for example, a PBT having no c unit and a polyolefin resin (B) results in poor dispersion and a small amount of component resin phase as large particles. And appears as a striped or layered phase separation structure on the surface of the injection molded product,
Surface layer peeling easily occurs due to friction. This is because the aromatic polyester resin (C) and the polyolefin-based resin phase (B) are deformed into a layered structure by the high shear force generated near the surface layer during injection molding, and the aromatic polyester resin phase (C) and the polyolefin-based resin It is considered that the surface layer peeling phenomenon occurs due to poor affinity and adhesiveness with the phase (B). On the other hand, by using or using a PBT-based polyester resin (A) containing a metal sulfonic acid salt, the dispersibility of each resin component is improved, and a dense and uniform dispersion state is obtained. It is understood that the formation of a molded article having a good surface condition can be obtained by suppressing the formation of the components and improving the adhesiveness of both components. The improvement in the dispersion state is supported by the fact that, when the cross section of the molded product of the present invention is observed with an electron microscope, the small components are extremely fine and uniformly dispersed (see Examples).

In order to further impart desired properties to the resin composition of the present invention without impairing its purpose, conventionally known additives such as lubricants, lubricants, nucleating agents, dyes and pigments, release agents And additives such as antioxidants, heat stabilizers, weather (light) stabilizers, hydrolysis stabilizers, inorganic or organic reinforcing agents or fillers, and other thermoplastic resins.

The composition of the present invention can be prepared by various known methods, but at least the PBT-based polyester resin (A) and the polyolefin-based resin (B) in the present invention.
If necessary, in the coexistence of the two components, the component (C) is preferably added and heated and melted, and the mixture is kneaded for 30 seconds or more. The other components may be mixed and used together, or may be added separately. Specifically, for example, after each component is uniformly mixed in advance with a kneader such as a tumbler or a Henschel mixer,
It may be supplied to a single-screw or twin-screw extruder, melt-kneaded, formed into pellets, and then subjected to molding, or may be directly molded.
Here, the melt kneading is preferably performed at a melting temperature at a shear rate of 40 sec ^-1 or more. Particularly preferred shear rates are between 100 and 500 sec ^-1 . The treatment temperature is 5 ° C to 100 ° C higher than the temperature at which the resin component melts, and particularly preferably 10 ° C to 60 ° C higher than the melting point. If the temperature is too high, decomposition or abnormal reaction occurs, which is not preferable. The melt-kneading time is at least 30 seconds to 15 minutes, preferably 1 to 10 minutes.

[0011]

EFFECT OF THE INVENTION The resin composition of the present invention has a structure in which a PBT-based polyester resin and a polyolefin-based resin are uniformly finely dispersed. It has a smooth molded surface, or has excellent mechanical properties, and has good adhesive workability as a composite molded product, and is expected to be used in many applications.

[0012]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto.

The evaluation and measurement methods are as follows. Evaluation of resin dispersibility If the polyolefin resin is a small component, break the pellet in liquid nitrogen and put it in a xylene solution.
After refluxing for hours, the polyolefin-based resin was eluted, and the generated pores were observed with an electron microscope to evaluate the dispersion state of the polyolefin-based resin (average particle diameter in the case of particle dispersion). That is, it is evaluated that the finer the dispersion state of the polyolefin resin (the smaller the average particle diameter), the more improved the dispersibility of the polyolefin resin. FIG. 1 shows a typical (Example 2) particle dispersion mode of the present invention. FIG. 2 shows a corresponding particle dispersion form in the case of not belonging to the present invention (Comparative Example 3). When the polyester component (A + C) was a small component, the pellets were crushed or cut and treated in a 1N aqueous solution of NaOH at 60 ° C. for 24 hours to decompose and elute the polyester and similarly evaluate the pores formed. . Tensile strength and elongation : Performed according to the method of ASTM D638. Notched Izod impact value : This was performed according to the method of ASTM D256. Surface Peeling Test : Scotch tape was adhered to the gate part of the tensile test piece, peeled off, and it was evaluated whether peeling occurred. Meltability : A 1mm thick film was prepared at 250 ° C with a press machine, and superimposed with the mating resin film shown in the table.
1mm which was quenched with cold water after fusing with a press machine at / cm ²
Thick samples were made according to the method of JIS C6481. Production Example of Polyester Copolymer (A) a Dimethyl terephthalate, b 1,4-butanediol, c Dimethyl dimethyl 5-sodium sulfoisophthalate (0.1, 1.5 mol% based on a + c) and titanium tetrabutoxide as a catalyst Was charged into a reactor equipped with a stirrer and a distilling tube. After sufficiently replacing the atmosphere with nitrogen, the temperature was raised, and transesterification was almost completed until the temperature reached 240 ° C (90% or more of the theoretical amount of methanol distilled). 2.5 at 0.1 Torr
The time polycondensation reaction was continued to obtain three types of modified PBT copolymers containing sodium sulfonate-containing isophthalic acid residues at 0.1, 1, and 5 mol%, respectively (A-1, A-2, A-3). . And c
Polycondensation was carried out in the same manner as in the preparation of (A-2), except that sodium paradihydroxyethoxyphenylsulfonate was used in an amount of 1 mol% based on the component (a-2) ( A'-2 ).

Examples 1 to 5 As shown in Table 1, (A) a polybutylene terephthalate copolymer polyester resin obtained by copolymerizing 0.1, 1.0 and 5 mol% of 5-sodium sulfoisophthalic acid (SIP) component
(A-1, A-2, A-3), (B) ethylene-zinc methacrylate copolymer (Himilan manufactured by Mitsui DuPont Polychemicals) (B-1), and (C) polybutylene in some cases Terephthalate (PBT) (manufactured by Polyplastics Co., Ltd.) was mixed at the ratio shown in Table 1, and melt-kneaded using a 30 mm twin screw extruder at a set temperature of 245 ° C. and a screw rotation speed of 80 rpm to form pellets. Next, test pieces were prepared from the pellets using an injection molding machine, and physical properties were evaluated. The results are shown in Table 1.

Comparative Examples 1 to 3 For comparison, (A) a modified PBT alone, (C) a polybutylene terephthalate (PBT) resin alone, and a modified PBT
In the case of the two-component system (B) and (C) not containing (A), evaluation was made in the same manner as in the above-mentioned Example. The results are shown in Table 1.

[0016]

[Table 1]

Examples 6 to 11 and Comparative Examples 4 to 8 Molded pieces were prepared and evaluated in the same manner as in the previous example except that the amounts of components (A), (B) and (C) were changed as shown in Table 2. did. Table 2 shows the evaluation results.

[0018]

[Table 2]

Examples 12 to 14 , Comparative Examples 9 to 11 The above component ( A-2) was used as the component (A), and an ethylene-vinyl alcohol copolymer (Kuraray Co., Ltd.) was used as the component (B).
Kuraray Eval Co., Ltd.) (B-2), ethylene-ethyl acrylate copolymer (Nippon Unicar Co., Ltd.) (B-3), maleic anhydride-modified polypropylene (Sumitomo Chemical Co., Ltd.)
In the case of using Sumitomo Noblene (B-4), a composition was prepared in the same manner, molded, and evaluated. Table 3 shows the results
It was also described in.

[0020]

[Table 3]

Examples 15 and 16 A composition was prepared in the same manner as in the case where a copolymer ( A'-2 ) containing 1 mol% of sodium paradihydroxyethoxyphenylsulfonate (HEPS) was used as the component (A). Then, it was molded and evaluated. The results are shown in Table 4.

[0022]

[Table 4]

[Brief description of the drawings]

FIG. 1 is an electron micrograph showing a typical (Example 2) particle structure (dispersed state) of a composition of the present invention.

FIG. 2 is an electron micrograph showing a particle structure (dispersed state) of a conventional composition not belonging to the present invention (Comparative Example 3).

Continuation of the front page (51) Int.Cl. ⁶ identification code FI C08L 67/00 C08L 67/00 // C08G 63/688 C08G 63/688 (58) Field surveyed (Int.Cl. ⁶ , DB name) C08L 23/00 C08L 29/04 C08L 31/02 C08L 33/02 C08L 35/00 C08L 67/00

Claims (3)

(57) [Claims] 1. A terephthalic acid or its ester form as the component (A)
An aromatic dicarboxylic acid or an ester-forming derivative thereof having a synthetic derivative as a main component ; b 1,4-butanediol;
A polycondensation reaction of a diol compound or an ester-forming derivative thereof as an ingredient and an ester-forming compound containing a metal sulfonic acid salt represented by the following general formula (I) and / or (II): resulting sulfonic acid metal salt-containing polybutylene terephthalate-based port Riesuteru copolymer resin component (a), relative to the sum of (B) and (C) 2
(A), (B) and (B) as the component (B), an olefin-based copolymer obtained by copolymerizing at least one of α, β-unsaturated carboxylic acid or its derivative, vinyl alcohol or its ester as the component (B). 2 to 98% by weight based on the sum of C) Polyester containing 0 to 96% by weight of aromatic polyester resin as component (C) based on the sum of resin components (A), (B) and (C) Resin composition. (XOCO) _m -Ar- (SO ₃ M) _n (I) (HORO) _m -Ar- (SO ₃ M) _n (II) (where -Ar- is a benzene ring or a naphthalene ring, and X
Is a hydrogen atom or a lower alkyl group. m and n are
1 or 2 respectively, M is lithium, sodium, potassium
If n is 2, the same alkali metal
May be. R is -CH ₂ CH _2- , -CH (CH ₃ ) CH _2- , -CH _{2
CH (CH 3) -, -} CH 2 CH 2 OCH 2 CH 2 - 2 divalent radical der selected from
You. ) 2. The general formula (I) constituting the component (A ) and
/ Or (II) sulfo <br/> phosphate metal salt-containing ester unit c which is formed by a compound represented by, introduced in an amount ranging from 0.01 to 15 mol% of the total ester units that constitute the component (A) The polyester resin composition according to claim 1, wherein the polyester resin is a polyester. 3. A molded article obtained by molding the polyester resin composition according to claim 1.