JP3075905B2 - 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 polyester resin composition having excellent impact resistance without deteriorating mechanical properties and having both noise reduction and vibration damping. More specifically, a saturated polyester resin (A) is blended with a polyester / block copolymer (B) having an amorphous or low-crystalline aromatic soft polyester as a soft component and a high-melting polyester as a hard component. The present invention relates to a polyester resin composition which is excellent in flexibility and excellent in quietness and vibration damping.

[0002]

2. Description of the Related Art Saturated polyester resins, especially crystalline saturated polyester resins, are widely used as a part of mechanical parts because of their high heat resistance and excellent mechanical strength as engineering plastics. However, if the material has hardness, resonance tends to occur with vibration, and this material becomes a source of noise.

Further, in recent years, with the development of home electric appliances and the like, there are many products in which movable parts such as small motors and relays are incorporated. Since a crystalline polyester resin is used as one component of these movable parts, the demand for this resin has been widened.

[0004] In order to improve the impact strength, rubber components are often blended. However,
Although the flexibility can be improved by blending this rubber, the following problems may occur even with a rubber having good compatibility. For example, when obtaining an injection-molded article having a welded part, the strength of the welded part may be extremely reduced as compared with a part where the weld is not welded, and particularly, the molded article containing the weld alternates between high and low temperatures. Causes a decrease in strength when placed in an environment. Accordingly, there is a need for a composition capable of preventing a decrease in weld strength, a decrease in strength due to a heat cycle of weld, and the like.

Further, if the composition can suppress vibration noise,
In the use of the component having the movable portion, it can be expected that the generated sound is reduced.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to enable injection molding and thermoforming as a molding resin material, to improve flexibility, to have a high strength retention rate at a weld portion, and to perform a cooling / heating cycle. The purpose of the present invention is to provide a composition which is less deteriorated even when is repeated.

[0007]

As a result of repeated studies to solve such problems, the present inventors have found that this problem can be solved by blending a specific polyester elastomer, and have reached the present invention.

That is, the present invention relates to a melting point comprising (A) 50 to 99% by weight of a crystalline saturated polyester resin and (B) (A) an aromatic dicarboxylic acid and a glycol having 5 or more carbon atoms as main components. Is 100% by weight or less of 100 % by weight of a polyester / ester block copolymer comprising 100 % or less or an amorphous polyester portion and (A) a crystalline polyester portion having a melting point of 150 ° C or more.
0.1 to 100 reinforcing fillers in the form of fibers and / or plates
It is a polyester resin composition formulated by weight .

The acid component in the polyester portion (A) of the polyester block copolymer having a melting point of 100 ° C. or less or an amorphous dicarboxylic acid residue of 60% or less.
In a preferred embodiment, the content is at least mol%. Also,
The glycol component of the saturated polyester resin (A) is an aliphatic diol having 2 to 4 carbon atoms and / or cyclohexane dimethanol, and the acid component is terephthalic acid, isophthalic acid and / or 2,6 naphthalenedicarboxylic acid. In addition, it is preferable to exhibit crystallinity.

The present invention will be described. The saturated polyester resin (A) is a linear aromatic dicarboxylic acid such as terephthalic acid, 2,6-naphthalenedicarboxylic acid, or 4,4′-diphenyldicarboxylic acid, and a glycol having 2 to 4 carbon atoms and / or cyclohexane. Polyester containing dimethanol as a main constituent and having excellent crystallinity and mechanical properties. Among them, those having a melting point of less than 260 ° C., preferably 200 to 250 ° C. are preferable, and polybutylene terephthalate is most preferable. In addition, a copolymer can be used in addition to the homopolymer, and as the copolymer component,
There is no particular limitation, as long as it can be generally used as a polyester copolymer component.

Next, the polyester block copolymer (B)
The aromatic dicarboxylic acid constituting the polyester portion (A) of the above is a dicarboxylic acid in which a carboxyl group is directly bonded to an aromatic ring such as a benzene ring or a naphthalene ring, for example, isophthalic acid, terephthalic acid, phthalic acid, naphthalenedicarboxylic acid And so on. Since the polyester portion (a) needs to have a low melting point or an amorphous property, when it is made into a polyester such as isophthalic acid or phthalic acid, the aromatic dicarboxylic acid having low linearity is 60 moles relative to the total acid component. % Or more is preferably used.

As the glycol having 5 or more carbon atoms,
Hexamethylene glycol, decamethylene glycol,
Examples thereof include 3-methylpentamethylene glycol and 2-methyloctamethylene glycol, and generally have 12 or less carbon atoms.

The polyester portion (A) is a polyester comprising the above-mentioned aromatic dicarboxylic acid and glycol. In addition to the above, for example, aliphatic and alicyclic dicarboxylic acids, aromatic and alicyclic, etc. May be copolymerized. It is necessary that the melting point of the polyester comprising the components constituting the polyester portion (A) is less than 100 ° C. or amorphous. The component (A) preferably has a melting point of less than 50 ° C. or is amorphous. When the melting point is as high as 100 ° C. or higher, the effect of improving the impact resistance is small, and the effect of improving the vibration suppression and noise reduction is also reduced.

In order to obtain a vibration-damping and silent effect at a temperature at which a molded article made of the polyester resin composition is to be used as a product, that is, within the range of 0 to 100 ° C., the polyester block co- The temperature at which the combined (B) component shows the maximum value of the dynamic loss tangent is from -20 ° C to 40 ° C.
It is advisable to adjust appropriately so as to reach the temperature of up to ° C. For example, in order to achieve vibration damping and silence near room temperature, it is often better to set the glass transition temperature to -15 to 0 ° C.

On the other hand, in order to improve flexibility, the glass transition temperature is preferably 0 ° C. or lower, and more preferably -10 ° C. or lower.

On the other hand, the melting point of the polyester part (A) of the polyester block copolymer (B) is 150
The polyester hard component having a temperature of at least 0 ° C. generally means terephthalic acid, 2,6-naphthalenedicarboxylic acid,
Polyesters whose main constituents are aromatic dicarboxylic acids having high linearity such as 4'-diphenyldicarboxylic acid and glycols having 2 to 4 carbon atoms or cyclohexanedimethanol are used. Among these, polybutylene terephthalate can be used most often. The other copolymerization component is not particularly limited, and has a melting point of 150 ° C.
All that is required is the above.

The ratio of the polyester part (A) to the polyester part (A) is usually 30/70 to 80/20.
(Weight ratio). When the ratio of the polyester portion (a) is increased, the mechanical strength is improved, but the dynamic loss tangent is reduced. When the maximum value of the loss tangent of the polyester block copolymer (B) in the present invention is 0.05 or less, the vibration damping and silent effect of the resin composition is reduced. In order to obtain a sufficient vibration damping and silencing effect, the maximum loss tangent of the polyester block copolymer (B) is preferably set to 0.1 or more. Therefore, the ratio of the polyester portion (A) and the polyester portion (A) constituting the polyester block copolymer (B) is 50/50 to 80/20.

The polyester block copolymer (B) of the resin composition of the present invention comprises a polyester portion (A) and a polyester portion (A). This polyester block copolymer is produced as follows. Is done. For example, a high-molecular-weight polyester corresponding to the polyester portion (a) and a high-molecular-weight polyester corresponding to the polyester portion (a) are subjected to a melt reaction, and the melting point is higher than the melting point of the high-molecular-weight polyester corresponding to the polyester portion (a). It can be produced by lowering the temperature by 2 to 40 ° C. However, it may be manufactured by other manufacturing methods. The polyester block copolymer usually has an intrinsic viscosity of 0.6 as measured at 35 ° C. in orthochlorophenol.
Or more, preferably 0.8 or more.

The present invention relates to a saturated polyester (A) of 50 to
99% by weight and polyester block copolymer (B)
Although it is a polyester composition comprising 1 to 50% by weight, a reinforcing filler may be added to further increase the rigidity.

The reinforcing filler is not particularly limited as long as its mechanical properties can be improved by blending. However, in order to increase the reinforcing effect and reduce the anisotropy, the fibrous filler and the plate are used. It is preferable to use the filler in combination with the filler. Here, for example, the fibrous filler has an aspect ratio of 10 to 10.
Glass fiber, carbon fiber having a length of 100 mm or less and 1 mm or less,
Graphite fibers, metal fibers and the like are common. The plate-like filler has an aspect ratio of 30 or more and an average diameter of 100.
Mica, plate glass (glass flakes), metal stays, and the like, which are from micron to 1000 microns, are common.

The polyester resin composition of the present invention is prepared by adding a fiber component to 100 parts by weight of a resin component comprising 50 to 99% by weight of the saturated polyester resin (A) and 1 to 50% by weight of the polyester block copolymer (B). It is obtained by melt-mixing 0.1 to 100 parts by weight of the shape or / and plate-like reinforcing filler. In order to enhance the impact resistance and the vibration-damping / silent effect, it is preferable to increase the ratio of the polyester block copolymer (B). However, when the amount of the polyester block copolymer exceeds 50% by weight, the rigidity is remarkably reduced, and it is often unsuitable for forming a structure. Further, in order to obtain a vibration damping and silencing effect, it is necessary to mix the polyester block copolymer in a minimum of 1% by weight or more, preferably 5% by weight or more. In particular, when the purpose is to suppress vibration and noise, it is preferable to use 10% by weight or more.

Further, a fibrous or / and plate-like reinforcing filler is blended for the purpose of compensating for the reduced rigidity caused by blending the polyester block copolymer for the purpose of silence. However, if 100 parts by weight or more of the reinforcing component is blended with respect to 100 parts by weight of the resin component, the vibration damping and silencing effect is impaired, and melt mixing becomes difficult, which is not practically suitable, and usually 5 to 80 parts by weight is used. You.

The method of melt-mixing is not particularly limited, and a typical method is to continuously melt-knead and pelletize it with an extruder.

The polyester resin composition of the present invention thus obtained can be used as a stabilizer, a pigment, another resin, a plasticizer and various other materials within a range that does not impair the object of the present invention, such as flexibility, vibration damping and noise reduction. Additives may be included.

[0025]

The polyester resin composition of the present invention, when maintaining the heat resistance, moldability, chemical resistance, etc. of a saturated polyester resin, while softening and improving the contact sensation, is particularly effective in improving the weld area. This has the effect of improving the impact strength and improving the vibration damping and quietness of the resin.

Further, even when the reinforcing filler is used, the vibration damping and noise can be maintained, and the rigidity can be imparted to such an extent that it can be used as a structural material.

[0027]

The present invention will be described more specifically with reference to the following examples. In addition, each measured value in an Example was calculated | required by the following method.

Tan δ: DuPont thermal analyzer DMA2
001 In the resonance mode, peak values at −20 ° C. to 40 ° C. were measured.

The molding was carried out using an injection molding machine at a cylinder temperature of 230 ° C. and a mold temperature of 60 ° C.

Reference Example 1 Dimethyl isophthalate 175
Part, 23 parts of dimethyl sebacate and 140 parts of hexamethylene glycol are subjected to a transesterification reaction with a dibutyltin diacetate catalyst, and then polycondensed under reduced pressure to give an intrinsic viscosity of 1.06.
An amorphous polyester (A) having no endothermic peak due to melting of the crystal was obtained by the DSC method. An intrinsic viscosity of 0.98 was obtained by separately polycondensing this polyester.
The polybutylene terephthalate (a) chip was dried, 107 parts were added, and the mixture was further reacted at 240 ° C. for 45 minutes, and then 0.1 part of phenylphosphonic acid was added.
The reaction was stopped. This polyester block copolymer (B) was taken out and made into chips to be used as raw materials. The melting point of this chip was 190 ° C. and the intrinsic viscosity was 1.03. Also
The tan δ peak was 16 ° C., and the rebound resilience at 20 ° C. was 12%.

Reference Example 2 Dimethyl isophthalate 125
, 54 parts of dimethyl sebacate and 140 parts of hexamethylene glycol were subjected to a transesterification reaction with a dibutyltin diacetate catalyst, followed by polycondensation under reduced pressure to obtain a polyester having an intrinsic viscosity of 1.06. Example 1
After blocking in the same manner as described above, a chip was formed to obtain a polyester block copolymer (B). The resulting chip tan
The δ peak was −8 ° C., and the rebound resilience at 20 ° C. was 46%. In this example, a polyester block copolymer (B) was synthesized by changing the dicarboxylic acid component and the glycol component as shown in Table 2.

Reference Example 3 Dimethyl terephthalate 31
, 23 parts of tetramethylene glycol and 65 parts of polytetramethylene glycol (average molecular weight 1500) were transesterified by a conventional method, and then subjected to a polycondensation reaction under reduced pressure to obtain a polyester having an intrinsic viscosity of 1.47.

Examples 1 to 3 Table 1 shows polybutylene terephthalate (intrinsic viscosity 1.03) (saturated polyester resin (A)), polyester block copolymer (B) of Reference Example 1, and glass fiber. In volume, 57 at 250 ° C
The mixture was melt-kneaded using a mm extruder. Table 1 shows the obtained results.
It was shown to.

[Comparative Examples 1 to 3] In Example 1, the polymer of Reference Example 3 was used instead of the polyester block copolymer (B), and the modified polypropylene HA300 manufactured by Tonen Petrochemical Company was used. , And the case where no elastomer component was added are also shown in Table 1.

[0035]

[Table 1]

Example 4 Using the block polyester copolymer (B) of Reference Example 2, the results of examination in the same manner as in Example 1 are shown in Table 2.

[0037]

[Table 2]

Example 5 Table 3 shows the results obtained using Reference Example 1 and using the saturated polyester (A) shown in Table 3 as the saturated polyester (A). In Table 3, PBN and P
ET is polybutylene naphthalate (intrinsic viscosity 0.75)
And polyethylene terephthalate (intrinsic viscosity 0.62)
Is shown.

[0039]

[Table 3]

[0040]

[Summary] A block polyester composed of a specific low-melting polyester and a high-melting polyester for the purpose of improving the impact resistance of a saturated polyester, particularly the strength of a weld portion, and obtaining a vibration-damping and quiet resin composition. This object was achieved by adding a copolymer.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-5-59616 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08G 63/16-63/21 C08L 67 / 00-67/04

Claims (5)

(57) [Claims] (A) a crystalline saturated polyester resin 5
0-99% by weight and (B) (A) a polyester portion having an aromatic dicarboxylic acid and a glycol having 5 or more carbon atoms as main components and having a melting point of 100 ° C. or less or an amorphous polyester; Polyester / ester block copolymer 5 comprising a crystalline polyester part having a temperature of not less than ° C
For 100 parts by weight of 0 to 1 % by weight, fibrous and / or
Or 0.1 to 100 parts by weight of a plate-like reinforcing filler
A polyester resin composition comprising: 2. The polyester resin composition according to claim 1, wherein the component (A) of the polyester / polyester block copolymer contains at least 60 mol% of an aromatic dicarboxylic acid residue as an acid component. 3. The saturated polyester resin (A) according to claim 1, wherein the glycol component comprises an aliphatic diol having 2 to 4 carbon atoms and / or cyclohexanedimethanol, and the acid component includes terephthalic acid, isophthalic acid and / or Or a polyester resin composition which is a crystalline saturated polyester resin comprising 2,6-naphthalenedicarboxylic acid. 4. The polyester / polyester block copolymer (B) has a maximum dynamic loss tangent of -20 ° C.
The polyester resin composition according to any one of claims 1 to 3, wherein the polyester resin composition is in a temperature range of -40C and the maximum value is 0.05 or more. 5. The polyester resin composition according to claim 1, which has a flexural modulus of 1000 MPa or more.