JPH0689234B2 - Polyester resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a novel polyester resin composition. More specifically, the present invention relates to a novel polyester resin composition capable of producing a molded product having good mechanical strength and good surface condition.

BACKGROUND OF THE INVENTION Polyester resin has the property that its strength is particularly increased by filling it with a reinforcing filler, and a polyester resin filled with a reinforcing filler is a plastic for automobiles and household electrical appliances. Widely used as a material for

Such a polyester resin is basically obtained by polycondensation of an unsaturated dibasic acid component and a diol (polyhydric alcohol) component. Conventionally, as the diol component, ethylene glycol, glycerin, diethylene glycol,
Alkylene glycols such as propylene glycol and pentaerythritol have been used, but recently, a technique of using alkylene glycol and polyalkylene glycol in combination has been used to improve the properties of the obtained polyester resin.

For example, Japanese Patent Application Laid-Open No. 61-190551 discloses an invention of a polycarbonate resin composition comprising a polyester resin and a polycarbonate resin in which polyalkylene glycol and alkylene glycol are used in combination as a diol component. The polyester resin of the resin composition disclosed in this publication has a diol component constituting the polyhydric alcohol as described above, and a polyester resin prepared using such a polyhydric alcohol is , Shows good moldability when used alone. In particular, since such polyester resin has good moldability at low temperature, the surface glossiness of the molded product obtained by using this resin is improved, and a molded product having good surface property can be produced. It has the advantage that it can.

However, according to the study by the present inventor, as described above,
It has been found that when a combination of polyalkylene glycol and alkylene glycol is used as the diol component, the mechanical strength of the obtained polyester resin tends to decrease.

Therefore, such a polyester resin is difficult to use alone and is usually used in combination with a polycarbonate resin as described in the above-mentioned publicly known.

Therefore, if it is possible to maintain the property that the surface property of the above-mentioned molded product of the polyester resin is improved and further impart mechanical strength to the molded product, this polyester resin is used alone in automobiles or household electric appliances. be able to. And since the surface property of the molded body is good,
Even when a conventional polyester resin is used, a better molded product can be manufactured.

[Object of the Invention] The present invention has been made based on the above circumstances,
An object of the present invention is to provide a polyester resin composition suitable for producing a molded product having both excellent mechanical strength and low-temperature moldability.

[Means for Achieving the Object] A constitution of the present invention for achieving the object is a diol repeating unit containing 1 to 45% by weight of a polyalkylene glycol component and 99 to 55% by weight of an alkylene glycol component,
Polyester resin composed of a difunctional carboxylic acid repeating unit, and an aromatic vinyl compound and α, β-
A copolymer derived from an unsaturated cyclic acid anhydride, 70: 3
A polyester resin composition, characterized in that it is contained in a weight ratio within the range of 0 to 95: 5.

Another embodiment of the polyester resin composition of the present invention is a polyester resin composition characterized by containing 5 to 200 parts by weight of a reinforcing filler with respect to 100 parts by weight of the polyester resin composition.

The polyester resin used in the present invention is prepared by using a polyalkylene glycol component and an alkylene glycol component as the diol repeating unit. Here, the content of the polyalkylene glycol component is 1 to the total amount of the diol repeating units constituting the resin.
It must be in the range of 45% by weight. In particular, 5
It is preferably in the range of 40% by weight. Further, the content of the alkylene glycol component needs to be within the range of 55 to 99% by weight based on the total amount of the diol repeating units constituting the resin. In particular, it is preferably in the range of 60 to 95% by weight. When the ratio of the polyalkylene glycol component to the alkylene glycol component deviates from the above range, moldability at low temperature is deteriorated, and the surface gloss of the obtained molded product is deteriorated.

Examples of such a polyalkylene glycol component include diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly (tetramethylene oxide) -α, ω-diol, and random ethylene oxide and 1,2-propylenoxide. Or a block copolymer etc. can be mentioned. Particularly, in the present invention, those having an average molecular weight in the range of 300 to 8000 are preferable, and those having an average molecular weight in the range of 400 to 3000 are particularly preferable. Further, among those having an average molecular weight within the above range, it is particularly preferable to use polyethylene glycol and tetramethylene glycol.

As the alkylene glycol component, those conventionally used can be used.

Examples of the alkylene glycol component used in the present invention include alkylene glycols having a carbon number in the range of 2 to 15 (eg, ethylene glycol, propylene-1,2-glycol, propylene-1,3-glycol, butylene-2). ,
3-glycol, hexane-1,6-diol, octane-1,
8-diol, neopentyl glycol and decane-1,
10-diol and the like).

Particularly in the present invention, it is preferable to use ethylene glycol and butylene-2,3-glycol.

The difunctional carboxylic acid repeating unit constituting the polyester resin used in the present invention together with the above-mentioned diol repeating unit is a difunctional carboxylic acid, a difunctional carboxylic acid ester, a difunctional carboxylic acid ester or a difunctional carboxylic acid ester which is usually used in the production of a polyester resin. It may be derived from a functional carboxylic acid anhydride or the like. The difunctional carboxylic acid repeating unit may be derived from a bifunctional resin group carboxylic acid or a derivative thereof, but in the present invention, an aromatic dicarboxylic acid, an aromatic dicarboxylic acid monoester, Those derived from aromatic dicarboxylic acid diesters, aromatic dicarboxylic acid anhydrides and the like are preferable.

Examples of the aromatic dicarboxylic acid may include terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid, and examples of the aromatic dicarboxylic acid anhydride may include terephthalic acid anhydride and naphthalenedicarboxylic acid anhydride. Furthermore, as the aromatic dicarboxylic acid monoester and aromatic dicarboxylic acid diester, lower esters of terephthalic acid, isophthalic acid and naphthalenedicarboxylic acid, preferably having 1 to 1 carbon atoms are used.
The monoester or diester with the alcohol of 3 can be mentioned.

Among them, the difunctional carboxylic acid repeating unit is preferably one derived from terephthalic acid or dimethyl terephthalate.

In the present invention, the difunctional carboxylic acid repeating unit preferably has an aromatic ring, as described above, but an aliphatic dicarboxylic acid (eg, oxalic acid, malonic acid, adipine) Acid, azelaic acid,
Sebacic acid and decanedicarboxylic acid, etc.) may be contained, and in this case, the content of the aliphatic dicarboxylic acid repeating unit in the difunctional carboxylic acid repeating unit in the polyester resin is 20 mol. % Or less is preferable. When a polyester resin containing an aliphatic dicarboxylic acid repeating unit with a content above this is used, the mechanical strength of the resulting molded article may be reduced.

The content ratio of the difunctional carboxylic acid repeating unit and the diol repeating unit in the polyester resin is usually in the range of 60:40 to 40:60 (preferably 55:45 to 45:55).

Such a polyester resin is obtained by heat-polymerizing a difunctional carboxylic acid component and a diol component in the presence or absence of a polymerization catalyst containing titanium, germanium, antimony, etc. according to a conventional method. hand,
It can be produced by discharging by-produced water or lower alcohol out of the system.

The resin composition of the present invention comprises an aromatic vinyl compound and α, β-
It includes a copolymer derived from an unsaturated cyclic acid anhydride.

Examples of aromatic vinyl compounds include compounds represented by the following formula.

However, in the above formula, R ¹ and R ² are each independently a group or atom selected from the group consisting of an alkyl group having 1 to 6 carbon atoms and a hydrogen atom, and R ³ and
R ⁴ is each independently one kind of atom or group selected from the group consisting of a chlorine atom, a bromine atom, a hydrogen atom and an alkyl group having 1 to 6 carbon atoms, and R ⁵ and R ⁶ are each independently, It is a group or atom selected from the group consisting of an alkyl group having 1 to 6 carbon atoms and a hydrogen atom. These compounds do not contain a substituent having a tertiary carbon atom.

In the present invention, it is particularly preferable to use styrene as the aromatic vinyl compound.

Examples of the α, β-unsaturated cyclic acid anhydride include compounds represented by the following formula.

However, in the above formula, the dotted line represents a carbon-to-carbon single bond or a double bond, provided that the compound contains at least one carbon-to-carbon double bond. R ⁷ is hydrogen and has 1 to 8 carbon atoms (preferably 1 to 8).
3) is one kind of group or atom selected from the group consisting of an alkyl group or an aryl group, R ⁸ is a hydrogen atom, a vinyl group, and an alkyl group having 1 to 12 carbon atoms (preferably 1 to 3), alkenyl A group or atom selected from the group consisting of a group, an alkylcarboxyl group and an alkenylcarboxyl group.

Specific examples of the α, β-unsaturated cyclic acid anhydrides include maleic anhydride, methylmaleic anhydride, dimethylmaleic anhydride, phenylmaleic anhydride, aconitic anhydride, and mixtures of these acid anhydrides. Can be mentioned. Of these, maleic anhydride is particularly preferable.

A copolymer derived from this aromatic vinyl compound and an α, β-unsaturated cyclic acid anhydride is already known, and in the present invention, for example, a bulk or solution polymerization method using a radical initiator or the like. Can be manufactured by.

For example, styrene, which is a typical example of the above copolymer,
The maleic anhydride copolymer can be produced by reacting styrene and maleic anhydride at 50 ° C. in the presence of a reaction disclosing agent such as benzoyl peroxide.

The molar ratio of the aromatic vinyl compound and the α, β-unsaturated cyclic acid anhydride in the copolymer thus obtained is usually within the range of 80:20 to 99: 1 (preferably 85: 15-95: 5
The number average molecular weight is usually 100,000 to
It is in the range of 400000. In the present invention, the copolymer may contain other monomer components as long as the characteristics of the copolymer are not impaired.

By blending a specific amount of the above specific copolymer with the polyester resin prepared by using polyalkylene glycol and alkylene glycol as the diol component in this manner, good low temperature moldability is maintained and mechanical properties are maintained. The strength can be improved.

That is, the polyester resin composition of the present invention is a composition containing the above polyester resin and a copolymer in a weight ratio within the range of 70:30 to 95: 5.

It is particularly preferable that the weight ratio of the both is within the range of 75:25 to 90:10. If the amount of the polyester resin is less than the above range, the moldability of the low temperature mold is lowered, so that the surface gloss of the molded body is lowered. On the other hand, if the content exceeds the above range, the mechanical strength of the obtained molded product becomes insufficient.

Further, the polyester resin composition of the present invention has particularly good mechanical properties and surface gloss when it contains a reinforcing filler within a range of 5 to 200 parts by weight based on 100 parts by weight of the polyester resin composition. A molded body can be manufactured.
In particular, the amount of the reinforcing filler compounded is preferably in the range of 10 to 80 parts by weight.

Generally, as the reinforcing filler of the resin, fibrous, granular, powdery or plate-like ones are used, and any of these reinforcing fillers can be used in the present invention. can do.

Among the reinforcing fillers used in the present invention, examples of fibrous reinforcing fillers include asbestos, metal whiskers, magnesium oxide fibers, fibrous magnesium oxysulfate, magnesium hydroxide fibers, potassium titanate fibers,
Examples thereof include glass fibers, calcium silicate fibers, carbon fibers, rock wool, silicon nitride whiskers, silicon carbide whiskers, and ceramic fibers and gypsum fibers which are alumina-silica glass fibers. In the present invention, among these, glass fiber can be preferably used. When using a fibrous reinforced filler, use one with an average fiber length of 0.1 mm or more (preferably 1 mm or more) and an asspeck ratio of 10 or more (preferably 100 or more). Is preferred.

Further, among the reinforcing fillers used in the present invention, as the granular, powdery and plate-like reinforcing fillers, for example, talc,
Calcium carbonate (heavy, light, colloidal), barium sulfate,
Mica, barium sulfate, calcium silicate, clay, kaolin, magnesium carbonate, wollastonite, alumina, silica, gypsum, iron oxide, calcium sulfate, glass beads, glass powder, white carbon, hollow glass spheres,
Quartz sand, carbon black, aluminum hydroxide, magnesium hydroxide, zinc oxide, white luster, basic magnesium carbonate, zeolite, molybdenum, titanium dioxide, diatomaceous earth, sericite, shirasu, graphite, calcium hydroxide, calcium sulfite, quartz Mention may be made of powder, bentonite, sodium sulfate and the like. Of these, talc is preferably used in the present invention. When a powdered reinforcing filler such as talc is used, it is preferable that the average particle size is 10 μm or less.

In the present invention, the reinforcing filler may be used alone or in combination of two or more kinds. The reinforcing filler may be used as it is, or may be subjected to a surface treatment, a sizing agent treatment, or the like. Examples of the treatment agent that performs such surface treatment and bundling treatment include a silane-based surface treatment agent, an epoxy-based sizing agent, and a urethane-based sizing agent.

The polyester resin composition of the present invention is a conventional kneading machine (for example, a twin-screw extruder, a single-screw extruder, a ribbon blender, a Henschel mixer, a Banbury mixer,
It can be produced by blending the polyester resin and the copolymer, and optionally a reinforcing filler using a drum blender, a co-kneader, etc.) and melt-kneading the mixture according to ordinary kneading conditions.

At this time, antioxidants (for example, phosphoric acid ester-based antioxidants, phosphite ester-based antioxidants), colorants, plasticizers, and ultraviolet absorbers (for example, benzotriazole-based materials) usually used for resins are used. Additives such as antioxidants, benzophenol-based antioxidants), external lubricants (for example, fatty acid esters, paraffins), colorants, plasticizers, flame retardants and release agents can also be added.

Further, other resin components may be added within a range that does not impair the characteristics of the resin composition of the present invention. in this case,
Examples of the resin to be blended include polyethylene resin, polypropylene resin, polystyrene resin, AS resin, ABS resin, polymethacrylate resin, polycarbonate resin and ordinary polyester resin.

The polyester resin composition thus obtained can be molded according to a conventional method, and the molded body can be used as, for example, automobile parts, parts for home electric appliances and the like.

[Effect of the Invention] By using the polyester resin composition of the present invention,
It is possible to manufacture a molded product having good mechanical properties such as flexural modulus, bending strength, and impact resistance, and good surface smoothness of the molded product. The above-mentioned mechanical properties and surface state of the molded product obtained by using the polyester resin composition of the present invention,
In both cases, the level is higher than that of the molded product obtained by using the conventionally used polyester resin.

In particular, the above-mentioned characteristics of the resin composition of the present invention are particularly remarkable when a reinforcing filler is used.

[Examples] Next, examples and comparative examples of the present invention will be described.

(Examples 1 to 7 and Comparative Examples 1 to 6) The polyester resins shown below were heated at 140 ° C. for 8 hours,
The copolymer was dried at 80 ° C. for 8 hours.

Then, the polyester resin and the copolymer and the reinforcing filler are mixed in the mixing ratio shown in Table 1, and the temperature of the cylinder is 260 ° C and the screw rotation speed is 1 using a twin-screw extruder.
Kneading was carried out under the condition of 50 rpm to produce pellets of the polyester resin composition containing a reinforcing filler.

The pellets thus obtained were dried at 140 ° C. for 8 hours, and then molded using an injection molding machine under the conditions of a cylinder temperature of 260 ° C. and a mold surface temperature of 90 ° C. to manufacture a test piece.

Table 1 also shows the results of the bending strength test of the obtained test piece according to JIS K 7203 and the bending strength test according to JIS K 7105.

Polyester resin a ₁ : Polycondensation product of diol component and terephthalic acid consisting of 14% by weight of polyethylene glycol having an average molecular weight of 1000 and 86% by weight of ethylene glycol;
82 dl / g (solvent = mixed solvent of phenol and tetrachloroethane mixed in a weight ratio of 1: 1; measurement temperature = 30)
℃) a ₂ ... Polycondensation polymer of terephthalic acid and diol component consisting of 24% by weight of average molecular weight of 1000% polyethylene glycol and 76% by weight of ethylene glycol; intrinsic viscosity 0.85dl
/ g (measurement conditions are the same as above) a ₃ ...... polyethylene terephthalate; an intrinsic viscosity of 0.68 dl / g
(KL236 RB, manufactured by Kuraray Co., Ltd.) Copolymer b ₁ ... Copolymer of 93 mol% styrene and 7 mol% maleic anhydride (manufactured by Idemitsu Petrochemical Co., Ltd., trade name: Moamax UG430, number) Average molecular weight: 200,000) Reinforcing filler C ₁ ...... Glass fiber; average fiber length: 3 mm, aspect ratio: 33
0, Treated product using epoxy-based sizing agent (Nittobo Co., Ltd.)
Manufactured by CS3J-941) c ₂ ...... talc; average particle size 2.8 μm C ₃ ... carbon fiber; (manufactured by Toho Bethlon Co., Ltd., trade name: Bethfight HTA-C6-S) It can be seen from Table 1 that the polyester resin composition of the present invention can produce a molded product having excellent mechanical strength and surface condition.

Claims (2)

[Claims] 1. A polyester resin composed of a diol repeating unit containing 1 to 45% by weight of a polyalkylene glycol component and 99 to 55% by weight of an alkylene glycol component, and a difunctional carboxylic acid repeating unit, and an aromatic compound. A polyester resin composition comprising a copolymer derived from a vinyl compound and an α, β-unsaturated cyclic acid anhydride in a weight ratio within the range of 70:30 to 95: 5. 2. A polyester resin composed of a diol repeating unit containing 1 to 45% by weight of a polyalkylene glycol component and 99 to 55% by weight of an alkylene glycol component, and a difunctional carboxylic acid repeating unit, and an aromatic compound. A copolymer derived from a vinyl compound and α, β-unsaturated cyclic acid anhydride, 5 to 200 with respect to 100 parts by weight of the resin component containing a weight ratio within the range of 70:30 to 95: 5. A polyester resin composition comprising a part by weight of a reinforcing filler.