JPH0539411A - Polyester-based resin composition - Google Patents

Abstract

PURPOSE:To obtain a polyester-based resin composition, excellent in heat resistance, flexibility, etc., improved in compression set and suitable as packing shock absorbers, etc. CONSTITUTION:A polyester-based resin composition is obtained by blending (A) 100 pts.wt. polyester-based resin with (B) 5-100 pts.wt. organopolysiloxane- modified polyolefin which is an organopolysitoxane-modified ethylene ethyl acrylate copolymer, etc., prepared by adding 10-800 pts.wt. organopolysiloxane expressed by the formula [R<1> is aliphatic unsaturated group; R<2> is (substituted) monofunctional hydrocarbon, etc., without containing the aliphatic unsaturated group; 0<=a<1; 0.5<b<3; 1<(a+b)<3] and 0.002-1 pt.wt. organic peroxide to 100 pts.wt. ethylene ethyl acrylate copolymer with 10-50wt.% ethyl acrylate content and thermally kneading the resultant mixture.

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention has heat resistance, flexibility, large load resistance, large bending fatigue resistance, excellent oil resistance, chemical resistance, and moldability, and has improved compression set. The present invention relates to a polyester resin composition.

[0002]

2. Description of the Related Art Polyester resin is a multi-block polymer that uses aromatic polyelter for the hard segment and mainly amorphous polyether for the soft segment. It can be used in a wide temperature range and has a large load resistance. It is a high-performance elastomer with high bending fatigue resistance, excellent oil resistance, chemical resistance, and good molding processability. It is used in electrical, electronic parts, automobile parts, industrial parts, miscellaneous goods, precision machine parts, etc. There is. However, materials such as packing, shock absorbers, coil tubes, etc. that compressively deform under heating conditions are required to have a small compression set, that is, good resilience, but polyester resins are better than other rubbers. It wasn't enough. For example, the compression set of organic rubber is generally 20% or less (measured under the conditions of JIS K6301 70 ° C. and 22 hrs), whereas that of polyester resin is strongly required to be improved within 50%.

[0003]

In view of such circumstances, the present invention improves the recoverability of packings, shock absorbers, coil tubes and the like produced from polyester resins, and therefore has excellent compression set. It is an object to provide a composition.

[0004]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that an ethylene ethyl acrylate copolymer having an ethyl acrylate content (hereinafter referred to as EA content) of 10% or more and 50% or less (hereinafter, It is called EEA.)
Alternatively, an organopolysiloxane and an organic peroxide are added and kneaded to an ethylene vinyl acetate copolymer (hereinafter referred to as EVA) having a vinyl acetate content (hereinafter referred to as VA content) of 10% or more and 50% or less. It was found that the compression set of the above problems can be improved by adding the organopolysiloxane-modified ethylene ethyl acrylate copolymer thus obtained or the organopolysiloxane-modified ethylene vinyl acetate copolymer to a polyester resin, and the present invention was completed. did. That is, the present invention is based on 100 parts by weight of the polyester resin, organopolysiloxane modified ethylene ethyl acrylate copolymer (hereinafter,
It is called EEA modified product. ) Or organopolysiloxane-modified ethylene vinyl acetate copolymer (hereinafter referred to as EVA modified product) in an amount of 5 to 50 parts by weight.

The present invention will be described in detail below. EE above
As the A-modified product, for AEA having an EA content of 10% or more and 50% or less, (A) the following formula (I): R ¹ _a R ² _b SiO _{4 -ab / 2} (wherein R ¹ is Aliphatic unsaturated group, R ² represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group, and a and b are under the following conditions: 0 ≦ a <1, 0.5 <b <3 10 to 800 parts by weight of the organopolysiloxane represented by the formula: 1 <a + b <3), and (B) the organic peroxide.
An EEA-modified product obtained by heating and kneading a composition containing 002 to 1 part by weight is preferable. Further, as the EVA modified product, (A) the following formula (I): R ¹ _a R ² _b SiO _{4 -ab / 2} (wherein R is the following, for EVA having a VA content of 10% or more and 50% or less) ¹ represents an aliphatic unsaturated group, R ² represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group, and a and b are under the following conditions: 0 ≦ a <1, 0.5 <b <3, 1 <a + b <3 is represented by a numerical value), 10 to 800 parts by weight of organopolysiloxane represented by the formula, and (B) organic peroxide 0 to
EVA modified products obtained by heating and kneading a composition containing 1 part by weight are preferable. The EEA used in the EEA-modified product of the present invention is an EEA having an EA content of 10 to 50%. If the EA content is less than 10%, the E obtained from it
When the EA modified product is added to the polyester resin, the compression set is not so much improved. When the EA content is more than 50%, the EEA is not practical because the EEA itself has severe stickiness and blocking, and the kneading is difficult. For EEA,
Ordinary commercial products can be used. EVA used for the EVA modified product of the present invention is EVA having a VA content of 10 to 50%. When the VA content is less than 10%, the compression set is not improved so much when the obtained EVA modified product is added to the polyester resin. 50% VA content
If it is more than EVA, EVA itself is sticky and difficult to knead. As EVA, a normal commercial product can be used.

The organopolysiloxane used in the present invention is represented by the above formula I, in which the R ¹ group is exemplified by vinyl group, allyl group, acryl group, methacryl group and the like, and R ² is represented by Alkyl groups such as methyl group, ethyl group, propyl group, aryl groups such as phenyl group, tolyl group, cycloalkyl groups such as cyclohexyl group, cyclobutyl group and hydrogen atoms partially bonded to carbon atoms of these hydrocarbon groups Examples thereof include a group substituted with a halogen atom, a cyano group, a mercapto group and the like, but these may be the same or different combination thereof. In the above formula I, a is 0
Alternatively, it is greater than 0 and less than 1. This range is because when a is 1 or more, the molded article produced by the present invention becomes too hard. a is preferably 0.0004-0.
It is 06. In the above formula I, b is greater than 0.5 and 3
Is less than. If this range is 0.5 or less, it is difficult to knead the composition of the present invention and the workability is poor, and if it is 3 or more, the molded article produced by the present invention becomes too hard, which is not desirable. b is preferably 1-2. The molecular structure of the organopolysiloxane in the present invention may be linear, branched, cyclic, reticulated, three-dimensional reticulated or the like as long as it has the structure represented by the above formula I. Examples of such an organopolysiloxane include so-called silicone gum stock, which is commercially available as a tear strength improver for silicone rubber.
The linear organopolysiloxane used in the present invention has the general formula:

[Chemical 1] (In the formula, R represents an unsubstituted or substituted monovalent hydrocarbon group, and n
Represents a number of 10 or more), and is generally called silicone oil. R in the above formula is a group selected from an alkyl group, an aryl group and a hydrogen atom,
Typical examples are methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, i-butyl group, t-butyl group, phenyl group and hydrogen atom. All R's in the molecule may be the same, some R's may be different groups, and some R's may be vinyl groups or hydroxyl groups. n is 10 or more, and 100 to 1000 is preferable. When n is less than 10, it is difficult to knead with polyethylene. The organopolysiloxane polymer represented by the above formula I used in the present invention has a viscosity at 23 ° C. of 10 CS or more, preferably 10 ³ to 10 ⁶ CS. When the viscosity is lower than 10 CS, heat kneading is difficult, and the organopolysiloxane polymer may exude from the surface of the molded product.

The organic peroxide that can be used in the present invention preferably has a decomposition temperature of 100 to 220 ° C. with a half-life of 10 minutes, that is, a 10-minute half-life temperature (T _P ) of 100 to 220 ° C. The following may be mentioned as examples [however, the temperature in parentheses is the decomposition temperature (° C)]: t-butylperoxyisopropyl carbonate (135), t-butylperoxylaurate (140), 2,5 -Dimethyl-2,5-di (benzoylperoxy) hexane (140), t-butylperoxyacetate (140), di-t-butyldiperoxyphthalate (140), t-butylperoxymaleic acid (140), cyclohexanone peroxide (1
45), t-butylperoxybenzoate (14
5), dicumyl peroxide (150), 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (155), t-butylcumyl peroxide (15)
5), t-butyl hydroperoxide (158), di-
t-Butyl peroxide (160), 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3
(170), di-isopropylbenzene hydroperoxide (170), p-menthane hydroperoxide (1
80), 2,5-Dimethylhexane-2,5-dihydroperoxide (213).

In the present invention, the amount of organopolysiloxane is 10 to 800 parts by weight based on 100 parts by weight of EEA. When it is less than 10 parts by weight, the effect of improving the compression set of the polyester resin composition is poor, and when it exceeds 800 parts by weight, the solubility in the polyester resin composition is poor. In the present invention, the amount of organic peroxide is E
It is 0.002-1 parts by weight with respect to 100 parts by weight of EA. If it is less than 0.002 part by weight, the modification reaction is unlikely to occur, and even if 1 part by weight or more is added, the improvement of the reaction effect is hardly recognized. On the contrary, if the addition amount is large, gel is increased in the EEA-modified product, which is not preferable. In the case of EVA, 0 to 1 part by weight may be 0. Further, a commonly used crosslinking aid can be used in combination with the organic peroxide. In the present invention, the kneading is 16
It is desirable to carry out at 0 ° C or higher and 200 ° C or lower. The kneading can be performed by using a Banbury mixer, a twin-screw extruder, or another ordinary kneader.

The EEA-modified product obtained by the above method is used together with the following polyester resin composition. EV
The same applies to the A-modified product. The polyester resin used in the present invention generally contains an aromatic polyester and an aliphatic polyester or an aliphatic polyether in its main chain, and has a Vicat softening point of 150 ° C. or lower measured by ASTM D-1525. Is desirable. Commercially available products can be used as these polyester resins. In the present invention, the blending amount of the EEA modified product or the EVA modified product is 5 with respect to 100 parts by weight of the polyester resin.
-100 parts is desirable. If it is less than 5 parts by weight, the effect of improving the compression set is small, and if it exceeds 100 parts by weight, the mechanical strength may decrease. In the present invention, the polyester resin and the EEA or EVA modified product are mixed by a known method. For example, single screw extruder, twin screw extruder,
A roll, a Banbury mixer, a kneader, a Henschel mixer, etc. are used.

Molding of the obtained polyester resin is carried out by a known method such as injection molding, extrusion molding, foam molding, rotational molding, compression molding, etc.
Used for electronic parts, automobile parts, industrial parts, miscellaneous goods, precision machine parts, etc. In particular, it is suitable when packing, a shock absorber, a coil tube, or the like, which requires a small compression set and is excellent. The polyester resin composition of the present invention may contain a resin additive that is usually used. For example, antioxidants, lubricants,
Various organic and inorganic pigments, UV inhibitors, dispersants, neutralizing agents, nucleating agents, flow improvers, dyes, carbon black,
Flame retardant, asbestos, glass fiber, whisker titanate, talc, silica, calcium carbonate, pumice, silica-alumina, kaolin, mica, etc. are added within a range that does not impair the physical properties of molded articles made from the polyester resin composition of the present invention You may.

[0011]

The present invention will be described in more detail based on the following examples, but the invention is not intended to be limited thereto. Example 1 EEA having an EA content of 25% (NUC manufactured by Nippon Unicar Co., Ltd.
-6570) 100 parts by weight and a viscosity at 23 ° C of 3
70 parts by weight of silicone gum stock having a methyl vinyl silicone content of 1.0% at 00000CS, 0.1 part by weight of an organic peroxide (Perhexin 25B manufactured by NOF CORPORATION) and an antioxidant (Irganox manufactured by Ciba-Geigy).
1010) 0.02 part by weight was kneaded with a Banbury mixer at 180 ° C. for 15 minutes, and the kneaded product was extruded with an extruder to obtain a pelletized EEA-modified product. The melt flow index of this pellet was measured according to JIS-K6760. In addition, this pellet is
Pressurized at 80 ° C. and 100 kg / cm ² to form a sheet, and the sheet has tensile strength and elongation according to JIS-K6760.
It was measured according to. Examples 2 to 3 The same operation as in Example 1 was repeated except that the amount of silicone gum stock was changed as shown in Table 1. Comparative Examples 1 to 3 EEA having an EA content of 7% (NU made by Nippon Unicar Co., Ltd.
The same operation as in Example 1 was repeated, except that C-6220) was used instead. Table 1 summarizes the production conditions of the EEA-modified products produced in Examples 1 to 3 and Comparative Examples 1 to 3 and the evaluation results.

[0012]

[Table 1]

Next, examples of the polyester resin composition obtained by blending these EEA-modified products with the polyester resin will be shown. Example 4 MFR was 15 g / 10 min. 40 parts by weight of the EEA-modified product pellet obtained in Example 1 was added to 100 parts by weight of the polyester resin (Perprene P-30B manufactured by Toyobo Co., Ltd.), and mixed for 20 minutes with a Henschel mixer. 40m of this mixture at a cylinder temperature of 190 ° C
It was extruded with an m2 screw extruder and pelletized. After that, press molding was performed at a press temperature of 180 ° C. and a compression pressure of 100 Kg / cm ^{2 to} obtain a compression set (JIS K6301 70).
C., 22 hrs) was measured. Examples 5 to 7 Example 4 except that the addition amount of the EEA modified product pellets was changed.
The same operation was repeated. Examples 8 to 9 The same operation as in Example 4 was repeated except that the EEA-modified product pellets obtained in Examples 2 to 3 were used. Comparative Examples 4 to 6 The same operation as in Example 4 was repeated except that the EEA-modified product pellets obtained in Comparative Examples 1 to 3 were used. Comparative Examples 7 to 8 Unmodified EEA instead of modified EEA
The same operation as in Example 4 was repeated using (NUC-6570). Comparative Example 9 The same measurement as above was performed using only the polyester resin Perprene P-30B. Table 2 shows the test conditions and results of Examples 4-9 and Comparative Examples 4-9.

[0014]

[Table 2]

Examples 10 to 11 EEA was used as EVA with a VA content of 20% (manufactured by Nippon Unicar
NUC-3460), and the same operation as in Example 1 was repeated except that the amount of silicon gum stock was changed as shown in Table 2. Comparative Examples 10 to 11 EEA is VA content of 5% EVA (Nippon Unicar N
UC-3808) was used, and the same operation as in Example 1 was repeated except that the amount of silicon gum stock was changed to that shown in Table 2. Examples 10-11 and Comparative Examples 10-1
Table 3 summarizes the production conditions of the EVA-modified product produced in 1 and the results of the evaluation.

[0016]

[Table 3]

Next, an example of a polyester resin composition obtained by blending these EVA modified products with a polyester resin will be shown. Examples 12-13 EEA modified product pellets obtained in Examples 10-11 E
The same operation as in Example 4 was repeated except that the VA modified pellet was used. Comparative Examples 12 to 13 EEA modified product pellets E obtained in Comparative Examples 10 to 11
The same operation as in Example 4 was repeated except that the VA modified pellet was used. Table 4 collectively shows the test conditions and results of Examples 12 to 13 and Comparative Examples 12 to 13.

[0018]

[Table 4]

[0019]

The polyester resin composition of the present invention is
Since organopolysiloxane-modified ethylene ethyl acrylate copolymer or organopolysiloxane-modified ethylene vinyl acetate copolymer is added, the compression set is small, and electrical, electronic parts, automobile parts, industrial parts, miscellaneous goods, precision machine parts Among them, in particular, it is widely applicable to a field requiring a small compression set, such as packing, shock absorber, coil tube, and the like.

Claims (3)

[Claims] 1. An organopolysiloxane-modified polyolefin is added in an amount of 5 to 1 with respect to 100 parts by weight of a polyester resin.
A polyester resin composition, which is blended in an amount of 00 parts by weight. 2. The organopolysiloxane-modified polyolefin (A) represented by the following formula (I): R ¹ _a, relative to 100 parts by weight of an ethylene ethyl acrylate copolymer having an ethyl acrylate content of 10% or more and 50% or less. R ² _b SiO _{4 -ab / 2} (In the formula, R ¹ represents an aliphatic unsaturated group, R ² represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group, and a and b are as follows. Condition: 0 ≦ a <1, 0.5 <b <3, 1 <a + b <3 is represented by a numerical value), 10 to 800 parts by weight of organopolysiloxane, (B) organic peroxide 0. The polyester resin composition according to claim 1, which is an organopolysiloxane-modified ethylene ethyl acrylate copolymer produced by heating and kneading a composition containing 002 to 1 part by weight. 3. The organopolysiloxane-modified polyolefin has a vinyl acetate content of 10% or more and 50% or more.
Based on 100 parts by weight of the following ethylene vinyl acetate copolymer, (A) the following formula (I): R ¹ _a R ² _b SiO _{4 -ab / 2} (wherein R ¹ is an aliphatic unsaturated group, R ² is Represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group, and a and b are the following conditions: Numerical values satisfying 0 ≦ a <1, 0.5 <b <3, 1 <a + b <3 The organopolysiloxane-modified vinyl acetate copolymer produced by heating and kneading a composition obtained by adding 10 to 800 parts by weight of organopolysiloxane represented by The polyester resin composition according to claim 1, wherein