JP3076385B2 - Silicone-modified polyester resin and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel silicone-modified polyester resin, a method for producing the same, and a molded article from the resin. More specifically, the silicone-modified polyester-based resin of the present invention has improved compression set, and is used alone or in combination with other resins as a novel material for electric, electronic parts, automobile parts, industrial parts, and miscellaneous goods. Used for relationships, precision machine parts, etc.

[0002]

2. Description of the Related Art A polyester resin is a multi-block polymer using an aromatic polyester for a hard segment and an amorphous polyether for a soft segment, and can be used in a wide temperature range, and has a large load resistance. A high-performance elastomer with high flex fatigue resistance, excellent oil and chemical resistance, and good moldability. Used for electrical, electronic, automotive, industrial, miscellaneous goods, and precision machine parts. I have. However, packing, shock absorbers that compress and deform under heating conditions,
A material such as a coil tube is required to have a small compression set, that is, a good resilience, but the polyester resin is not sufficient compared to other rubbers. For example, the compression set of organic rubber is generally 20% or less (J
IS K6301 Measured at 70 ° C for 22 hours)
On the other hand, the content of the polyester-based resin is about 50% or more, and its improvement has been strongly demanded.

[0003]

In view of such circumstances, an object of the present invention is to provide a method for producing a modified polyester resin by reacting a polyester resin with another polymer, and a method for producing a polyester resin obtained by this method. An object of the present invention is to provide a modified polyester resin having an improved compression set and a molded product thereof.

[0004]

Means for Solving the Problems The present inventors have conducted a number of experiments on the combination of a polyester resin with another polymer, and as a result, have found that the combination with silicone achieves the above object. We have found and completed the present invention. That is, the present invention relates to (A) the following formula I: R ¹ _a R ² _b SiO _{4-ab / 2} (wherein R ¹ is an aliphatic unsaturated group, and R ² is Represents an unsubstituted or substituted monovalent hydrocarbon group containing no aliphatic unsaturated group, and a and b are numerical values satisfying the following conditions: 0 ≦ a <1, 0.5 <b <3, 1 <a + b <3 Wherein the composition is obtained by adding 10 to 200 parts by weight of an organopolysiloxane represented by the following formula (B) and 0.01 to 1 part by weight of an organic peroxide (B), and heat-kneading the composition. The present invention relates to a method for producing a resin. The present invention also relates to a silicone-modified polyester-based resin produced by the above method, and a molded article produced from the resin.

Hereinafter, the present invention will be described in detail. 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 measured by ASTM D-1525 of 150 ° C or less. desirable. Commercially available polyester resins can be used.

The organopolysiloxane used in the present invention is represented by the above-mentioned formula I, wherein R ¹ is exemplified by vinyl, allyl, acryl, methacryl and the like, and R ² is methyl. Groups, ethyl groups, propyl groups and other alkyl groups, phenyl groups and tolyl groups and other aryl groups, cyclohexyl groups and cyclobutyl groups and other cycloalkyl groups, and hydrogen atoms bonded to the carbon atoms of these hydrocarbon groups are partially halogenated. Examples thereof include a group substituted with an atom, a cyano group, a mercapto group and the like, and these may be the same or different combinations thereof. In the above formula I, a is 0 or more than 0 and less than 1. This range is because if a is 1 or more, the molded article produced by the present invention becomes too hard. a is preferably 0.0004 to 0.
06. In the above formula I, b is greater than 0.5 and 3
Is less than. When the range is 0.5 or less, it is difficult to knead the composition of the present invention, and the processability is inferior. When the range is 3 or more, the molded article produced by the present invention becomes too hard, which is undesirable. b is preferably 1 to 2. The molecular structure of the organopolysiloxane in the present invention may be any of linear, branched, cyclic, network, and three-dimensional networks as long as it is represented by the above formula I. Such organopolysiloxanes include, for example, so-called silicone gum stocks which are commercially available as tear strength improvers for silicone rubber.
In addition, the linear organopolysiloxane used in the present invention has a general formula:

Embedded image (Wherein, R represents an unsubstituted or substituted monovalent hydrocarbon group,
n represents a number of 10 or more), and there is one generally called silicone oil. R in the above formula is a group selected from an alkyl group, an aryl group and a hydrogen atom, and is a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, an i-butyl group, a t-butyl. Groups, phenyl groups and hydrogen atoms are typical. All the Rs in the molecule may be the same, some Rs may be different groups, and some of the Rs may be vinyl groups or hydroxyl groups. n
Is 10 or more, and 100 to 1000 is preferred. If n is less than 10, kneading with polyethylene is difficult. The viscosity at 23 ° C. of the organopolysiloxane polymer represented by the above formula I used in the present invention is 10 CS or more, preferably 10 ³ to 10 ⁶ CS. When the viscosity is lower than 10 CS, it is difficult to knead by heating, and the organopolysiloxane polymer may seep out from the surface of the molded article.

The organic peroxide which can be used in the present invention preferably has a decomposition temperature of 100 to 220 ° C. with a half-life of 10 minutes, ie, a half-life (Tp) of 100 to 220 ° C. for 10 minutes. Examples thereof include the following (provided that the decomposition temperature (° C.) is in parentheses): 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-butyl peroxybenzoate (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 the organopolysiloxane is 10 parts by weight based on 100 parts by weight of the polyester resin.
２００200 parts by weight. When the amount is less than 10 parts by weight, the effect of improving the compression set of the modified polyester resin is poor, and when it exceeds 200 parts by weight, the mechanical strength of the modified polyester resin deteriorates. In the present invention, the amount of the organic peroxide is based on 100 parts by weight of the polyester resin.
It is 0.01 to 1 part by weight. At 0.01 parts by weight or less,
The denaturation reaction hardly occurs, and even if 1 part by weight or more is added, little improvement in the reaction effect is observed. Conversely, if the amount of addition is large, gels are undesirably increased in the modified polyester resin. A commonly used crosslinking aid can be used in combination with an organic peroxide. In the present invention, kneading is performed at 160 ° C.
It is desirable to carry out at 50 ° C. or lower. Kneading is Bunbury
It can be carried out by a mixer, a twin-screw extruder, or another ordinary kneader.

The silicone-modified polyester resin of the present invention may contain a commonly used resin additive.
For example, antioxidants, lubricants, organic and inorganic pigments, UV inhibitors, dispersants, neutralizers, nucleating agents, flow improvers,
Dye, carbon black, flame retardant, asbestos, glass fiber, whisker titanate, talc, silica, calcium carbonate, pumice, silica alumina, kaolin, mica, etc. You may add in the range which does not impair.

[0010]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 MFR was 15 g / 10 min. With respect to 100 parts by weight of a polyester resin (Perprene P-30B manufactured by Toyobo Co., Ltd.), the viscosity at 23 ° C. was 300,000 CS,
50 parts by weight of a silicone gum stock having a methylvinyl silicone content of 1.0% and an organic peroxide (manufactured by NOF Corporation)
0.1 parts by weight of perhexin 25B) and 0.02 parts by weight of an antioxidant (Irganox 1010 manufactured by Ciba Geigy) were kneaded with a Banbury mixer at 180 ° C. for 15 minutes, and the kneaded product was extruded with an extruder to form a pelletized polyester resin denatured resin. I got something. The melt flow index of the pellet was measured according to JIS-K6760. The pellets were heated at 180 ° C, 1
The sheet was pressed at 00 kg / cm ² to form a sheet, and the sheet tensile strength and elongation were also measured according to JIS-K6760. In addition, compression set (JIS K63017)
(0 ° C., 22 Hrs). Examples 2 to 8 The same operation as in Example 1 was repeated except that the amounts of the silicone gum stock and the organic peroxide were changed as shown in Table 1. Comparative Examples 1 to 4 The same operation as in Example 1 was repeated except that the amount of the silicone gum stock and the amount of the organic peroxide were changed as shown in Table 1. Comparative Example 5 The same measurement as above was performed using only the polyester resin Perprene P-30B.

[0011]

[Table 1]

[0012]

[Table 2]

EFFECT OF THE INVENTION The silicone-modified polyester resin of the present invention has a small compression set and is particularly suitable for packing, shock absorbers in electric, electronic parts, automobile parts, industrial parts, miscellaneous goods, precision machine parts and the like. It can be widely applied to fields requiring a small compression set such as a coil tube.

Continuation of front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08G 63/00-63/91 C08G 77/445

Claims (3)

(57) [Claims] 1. A method for producing a polyester resin, comprising: (A) the following formula I: R ¹ _a R ² _b SiO _{4-ab / 2} (wherein R ¹ is an aliphatic unsaturated group, and R ² is a fatty acid) Represents an unsubstituted or substituted monovalent hydrocarbon group containing no group unsaturated group, and a and b represent numerical values satisfying the following conditions: 0 ≦ a <1, 0.5 <b <3, 1 <a + b <3 Wherein the composition comprises 10 to 200 parts by weight of an organopolysiloxane represented by the following formula (B) and 0.01 to 1 part by weight of an organic peroxide (B): Manufacturing method. 2. A silicone-modified polyester resin produced by the method according to claim 1. 3. A molded article produced from the silicone-modified polyester resin according to claim 2.