JPH06207086A - Thermoplastic polyester elastomer composition and its production - Google Patents

Abstract

PURPOSE:To obtain a thermoplastic polyester elastomer composition which is softer than the conventional thermoplastic polyester elastomers, and has good moldability and good mold release. CONSTITUTION:The composition is produced by mixing a thermoplastic polyester elastomer (a) with a noncrystalline rubber (b) having reactive functional groups and a compound (c) having at least two functional groups which can cross-link component (b) in such amounts that the (a) to (b) weight ratio is (5-95)/(95-5) and the number of the functional groups of component (c) is 0-3 times as large as that of the functional groups of component (b). A process for producing the above composition is characterized by conducting the cross-linking reaction of component (b) during the melt mixing of the respective components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic polyester elastomer composition and a method for producing the same, and more specifically, by dispersing a crosslinked rubber in a conventional thermoplastic polyester elastomer (hereinafter referred to as TPE), Realizes an elastomer with a lower elastic modulus than conventional TPE, and at the same time has good moldability and mold releasability, and expands its field of application to molded products that were advantageous to conventional rubber products. Can include, for example, emblems, ski boot components, door latch strikers,
Hot curler, bottle stopper, comb, brush, cable cover,
In applications such as telephone wire curl cords, it is more flexible than conventional thermoplastic polyester elastomers and exhibits excellent properties at low temperature impact, as well as hoses, diaphragms and rebounds that were previously advantageous for rubber products. It can also be used for stoppers and dust seals.

[0002]

2. Description of the Related Art Conventionally, thermoplastic polyester elastomer (TPE) has been widely used in a wide range of fields because of its good moldability, heat aging resistance and chemical resistance.
On the other hand, there is a limit to the low elastic modulus due to the copolymer composition, and the price is high. Therefore, attempts have been made to add non-crystalline polymers typified by rubber to TPE. However, because of poor compatibility with TPE, the desired physical properties may not be obtained, or some of the material surface may not be obtained. As a result of the rubber being exposed, there is a drawback that the moldability and releasability deteriorate.

[0003]

DISCLOSURE OF INVENTION Problems to be Solved by the Invention
The object is to realize low elastic modulus and low cost by dispersing in PE. Furthermore, this dispersion is not by mechanical kneading, but by dispersing while internally crosslinking the rubber having a reactive group, the moldability is improved. The object is to obtain a thermoplastic elastomer having a low elastic modulus while maintaining releasability.

[0004]

[Means for Solving the Problems] In order to solve the above-mentioned problems, the inventors of the present invention have earnestly studied, studied, and finally finally completed the present invention. That is, the present invention has (a) a thermoplastic polyester elastomer, (b) an amorphous rubber having a reactive functional group, and (c) two or more functional groups capable of crosslinking the component (b). Containing a compound, the composition ratio of which is (a) / (b) = 5 to 95
/ 95 to 5 (weight ratio), and the number of functional groups of the component (c) is 0 to 3 times equivalent to the number of functional groups of the component (b). Thermoplastic polyester elastomer composition and (a) thermoplastic polyester elastomer, (b) non-crystalline rubber having a reactive functional group, and (c) two or more functional groups capable of crosslinking the component (b). In the method for producing a composition containing a compound having the above, the crosslinking reaction of the above-mentioned component (b) is carried out during melt mixing of the respective components, which is a method for producing a thermoplastic polyester elastomer composition.

The TPE used as the component (a) in the present invention is a block copolymer composed of a high melting point polyester segment (hard segment) and a low melting point polymer segment (soft segment) having a molecular weight of 400 to 6000. The melting point of the high polymer formed only by the high melting point polyester segment constituent portion is 150 ° C or higher, and the melting point or softening point measured by only the low melting point polymer segment constituent component is 80 ° C or lower. It is a thermoplastic polyester elastomer composed of constituent components and has a melting point of 80 ° C. or higher.

The polyester constituting the high melting point polyester segment is terephthalic acid, isophthalic acid, 1,
5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, bibenzoic acid, bis (p-carboxyphenyl) methane, 4,4-
Residues of aromatic dicarboxylic acids such as sulfonyldibenzoic acid and ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, 2,2
A polyester comprising a diol residue such as dimethyltrimethylene glycol, hexamethylene glycol, decamethylene glycol, p-xylene glycol, cyclohexanedimethanol, or a copolyester using two or more kinds of these dicarboxylic acids or two or more kinds of diols Alternatively, oxyacids such as p- (β-hydroxyethoxy) benzoic acid and p-oxybenzoic acid, and polyesters derived from residues thereof, polylactones such as polypivalolactone, 1,4-bis (4,4) 4'-
A polyether ester comprising a residue of an aromatic ether dicarboxylic acid such as dicarboxydiphenoxy) ethane and the above-mentioned diol residue, and the above-mentioned dicarboxylic acid,
Among the copolyesters containing oxyacids, diols and the like in an arbitrary composition ratio, those having a melting point of 150 ° C. or higher can be mentioned. Among these, in the present invention, a copolyester composed of an aromatic dicarboxylic acid and an aliphatic diol is preferable, and polybutylene terephthalate is particularly preferable.

The low melting point polymer segment constituting the TPE which is the component (a) shows a substantially amorphous state at room temperature in the copolymer with the high melting point polyester segment. It has a melting point or softening point of 80 ° C. or less when measured only in the constituent parts, and its molecular weight is suitably 400 to 6000. Also, TP
The ratio of the low melting point polymer segment constituents in E is 3 to 9
It is 0%. Typical low melting point polymer segment constituents include, for example, polyether glycols such as polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol and mixtures thereof, and further polyether constituents thereof. The copolymerized polyether glycols are shown. Further, a polyester composed of an aliphatic or alicyclic dicarboxylic acid having 2 to 12 carbon atoms and an aliphatic or alicyclic glycol having 2 to 10 carbon atoms, for example, polyethylene adipate,
Aliphatic polyesters such as polytetramethylene adipate, polyethylene sebacate, polyneopentyl sebacate, polytetramethylene dodecanoate, polytetramethylene azetate, polyhexamethylene azetate, poly-ε-caprolactone and two or more of them Examples thereof include aliphatic copolyesters obtained by using an aliphatic or alicyclic dicarboxylic acid and two or more kinds of aliphatic or alicyclic glycols. Further, a mixture or copolymer of the above aliphatic polyester and aliphatic polyether can also be mentioned. Among them, polyoxytetramethylene glycol and poly-ε-caprolactone are preferable in the present invention, and polyoxytetramethylene glycol is particularly preferable.

The rubber which is the component (b) used in the present invention is a polymer compound which exhibits a substantially amorphous state at room temperature and has a functional group capable of reacting. The amorphous rubber as the component (b) is not particularly limited, but a thermoplastic or uncrosslinked rubber that is stable and does not rapidly crosslink at high temperature (150 ° C. or higher) is desirable. For example, a crystalline polyolefin segment such as polyethylene or polypropylene and polyvinyl acetate, polymethyl acrylate, polyethyl acrylate, or a polyethylene-polypropylene copolymer, or a compound having a conjugated double bond with polyethylene-polypropylene (for example, 1,3-butadiene). , Isoprene, chloroprene) copolymer (so-called EPDM
Or the like) or a di- or multi-block copolymer with an amorphous segment obtained by a combination thereof, a so-called polyolefin elastomer, a block copolymer of polystyrene and a diene compound such as 1,3-butadiene or isoprene, a so-called , Styrene-butadiene rubber. Alternatively, as described above, 1,3-butadiene, isoprene, a polymer of a diene compound such as chloroprene or the like, or a copolymer thereof with an α-olefin such as polyethylene or polypropylene, or a copolymer with acrylonitrile, a so-called so-called Diene rubber. Furthermore, some of these,
The thing which added hydrogen and hydrogen oxide is also mentioned. Further, any mixture or copolymer of the above polymers is also included in the component (b) defined in the present invention. Among these, polyolefin elastomers are preferable in the present invention, and ethylene-acrylic acid ester multiblock copolymers are particularly preferable.

Typical reactive functional groups contained in the component (b) include epoxy groups, maleic anhydride units, amino groups, carboxyl groups, groups having high reactivity such as carbon-carbon multiple bonds, and tosyl groups. And a group such as iodine, which is easily eliminated, such as a halogen atom. (B) of these functional groups
The method of introducing the component is not particularly limited,
For example, a method of introducing it into the main chain in the form of a copolymer or a method of introducing it by a grafting reaction using a technique such as a radical reaction is convenient. Of these, an epoxy group that reacts with the carboxylic acid terminal of the component (a) to obtain good compatibility is preferable, and particularly good results are obtained when glycidyl methacrylate is introduced as a copolymer. The concentration of the reactive group depends on the type of the functional group and the molecular weight of the repeating unit of the component (b). For example, the concentration of the functional group of the ethylene-methyl acrylate-glycidyl methacrylate copolymer is 10 to 1000. Pieces / 10 ⁶ g are suitable. Among them, from the viewpoint of compatibility and moldability, 70 to 7
50 pieces / 10 ⁶ g is preferable. Especially 200-500 pieces / 1
0 ⁶ g is preferred. Further, regarding the butadiene-acrylonitrile copolymer, (in this case, the functional group is
Think of it as a carbon double bond. ) 14000-28000 pieces /
10 ⁶ g (10 to 50 parts by weight in terms of the amount of bound acrylonitrile) is suitable. Above all, 170 in terms of product performance
It is preferably from 0 to 20000 pieces / 10 ⁶ g.

The cross-linking agent which is the component (c) used in the present invention is required to contain two or more functional groups capable of reacting with the functional group of the component (b). From the viewpoint of speed, the component (c) is preferably a low molecular weight compound. In addition, when the reactive functional group of the component (b) is highly reactive like an epoxy group and a crosslinking reaction occurs between them during the production of the composition, the component (c) is necessarily present. There is no. The functional group concentration of the component (c) is appropriately 0.01 to 3 times the equivalent of the functional group of the component (b). Preferred functional groups vary widely depending on the type of the component (b), but when the component (b) has an epoxy group, a carboxylic acid group as a reactive functional group,
There are amino groups, isocyanate groups and the like. The component (c) needs to be a compound having two or more functional groups among the above-mentioned functional groups, but regarding the isocyanate group, if other functional groups are present in the component (c), the reaction between them occurs. Is generated, which is not preferable.

Specific examples of low molecular weight compounds satisfying these conditions are adipic acid, sebacic acid, glutaric acid, dimer acid, terephthalic acid, isophthalic acid, trimellitic acid, 3- (3'-propanoic acid)- 1,7-Heptanedioic acid, polycarboxylic acids such as ethylenediaminetetraacetic acid, hexamethylenediamine, pentamethylenediamine, di-
(Aminomethyl) -benzene, tri- (aminomethyl)
-Polyamines such as benzene, glycine, alanine, β-
Examples thereof include amino acids such as alanine and glutamic acid, and polyisocyanates such as methylene-bis-phenylene isocyanate and hexamethylene diisocyanate. Among the above, from the viewpoint of easy availability and reaction rate, (b)
If the component has an epoxy group, adipic acid is preferred. Further, any of the above-described polymer compounds having a functional group, and further the case where the component (b) contains the functional group, all are included in the scope of the present invention. When the component (b) has another functional group, for example, in the case of a diene rubber, a typical crosslinking agent such as a sulfur-based, peroxide-based, halogen-based, epoxy-based, diene-based or dimaleimide-based crosslinking agent is used. Can be used. Further, any of the above-described polymer compounds having a functional group, and further the case where the component (b) contains the functional group, all are included in the scope of the present invention. Of these, N, N'-m-phenylenedimaleimide is preferable from the viewpoint of high-temperature crosslinking reaction characteristics. Other examples of the component (c) suitable for the functional group of the component (b) are not listed here, but a compound according to the gist of the present invention can be selected.

In the composition of the present invention, when the component (b) is an amorphous rubber having a self-crosslinking function, the component (c) does not necessarily have to be contained. Such rubbers include one or two that can cross-link with each other in their repeating units.
It is a polymer compound having at least one kind of functional group and showing a substantially amorphous state at room temperature. As the main repeating unit of the rubber which is in a substantially amorphous state at room temperature, a polymer compound according to the example of the component (b) can be used. As an example of a combination of functional groups capable of undergoing a crosslinking reaction, an epoxy group-carboxylic acid group, an amino group-carboxylic acid group and the like are considered.
Further, a functional group capable of undergoing a crosslinking reaction even if only one kind of functional group is present, for example, an epoxy group or an isocyanate group may be used. Further, the above combinations also fall within the scope of the present invention. The total concentration of these functional groups is 10-200.
0/10 ⁶ g is suitable, 100 to 1000/10 ⁶ g is preferable, and 225 to 550/10 ⁶ g is particularly preferable from the viewpoint of moldability and the cost of introducing a functional group. When the crosslinkable functional group is a combination of two kinds, it is preferable that the concentration of the larger functional group is less than 10 times the equivalent in order to reduce the functional groups that do not contribute to crosslinking as much as possible. Specific examples of the polymer compound satisfying the above conditions include ethylene-acrylic acid-glucidyl methacrylate terpolymer.

In the composition of the present invention, the amount of each of the above components is (a) / (b) = 5 to 95/95 to 5 (weight ratio),
The compounding ratio is such that the number of functional groups in (c) is 0 to 3 times equivalent, preferably 0.01 to 3 times equivalent to the number of functional groups in (b). Among them, (a) / (b) = 6 from the viewpoint of flow characteristics during molding and surface characteristics of the molded product.
The range of 0-95 / 40-5 is preferable. When the functional group of the component (b) is an epoxy group, the functional group concentration of the component (c) is 0.1 to 0.3 with respect to the functional group of the component (b).
Double equivalents are preferred.

Next, the method for obtaining the composition of the present invention is not limited at all, but the internal crosslinking reaction of the component (b) must be carried out during the melt mixing of the respective components. Specifically, a method of melt mixing the three components together using a roller kneader, a single-screw or multi-screw extruder,
A method in which the component (a) and the component (b) are melt-mixed and the component (c) is melt-mixed in the mixture, and the component (c) is melt-mixed while the component (a) and the component (b) are melt-mixed. How to add,
A method in which the components (a) and (c) are melt-mixed and the component (b) is melt-mixed into the mixture, and the component (b) is added during the melt-mixing of the components (a) and (c). The method etc. can be adopted. However, when the reaction between the component (b) and the component (c) is extremely fast, the above method is not preferable.

[0015]

The reason why the thermoplastic polyester elastomer composition of the present invention has a low elastic modulus and can maintain good moldability and releasability is that the components (b) and (a) react chemically. , The component (b) can be finely dispersed in the component (a), and the internal cross-linking of the component (b) allows the component (b) to have a larger volume fraction than the component (a) ( Since the component (a) can be a continuous phase, thermoplasticity, moldability and releasability can be maintained, and since the component (b) is crosslinked, rubber elasticity can be more easily exhibited ( It is considered possible to lower the elastic modulus and improve the permanent set characteristics).

[0016]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. However, the present invention is not limited by the following Examples, and is in a range that conforms to the gist of the preceding and the following. Any modifications and implementations are within the technical scope of the present invention. As a method of measuring each physical property in Examples and Comparative Examples, regarding the elastic modulus, ASTM-D
Flexural modulus obtained according to 790, low temperature impact resistance, according to ASTM-D256, after cooling to -30 ℃,
It was measured with a 150 kg hammer from an angle of 128 °.
As for moldability, whether or not molding was possible, the degree of sinking of the molded product, the condition of the surface of the molded product and the occurrence of burrs were visually observed.

Examples 1 to 4 and Comparative Examples 1 to 4 As a component (a), a thermoplastic polyester elastomer (P-55B manufactured by Toyobo Co., Ltd. (polybutylene terephthalate for the hard segment and a molecular weight of about 1000 for the soft segment) was used. Polytetramethylene glycol,
(Thermoplastic polyester elastomer having a repeating unit ratio of 5.5: 1) and a polyolefin rubber (manufactured by Sumitomo Chemical Co., Ltd .; bond fa) as the component (b).
st 20M) and the predetermined amount shown in Table 1 is 250
After melt-kneading and pelletizing in a 30mm twin-screw extruder under the condition of ℃, add a predetermined amount of adipic acid, and again pelletize through the twin-screw extruder under the same conditions. Got a test piece of. The component (a) in Example 4 and Comparative Example 4 is P-30B manufactured by Toyobo Co., Ltd. (the hard segment is polybutylene terephthalate, and the soft segment is about 200 in molecular weight).
The melting temperature was 220 ° C using a polytetramethylene glycol of 0 and a ratio of repeating units thereof being 3: 1. Table 1 shows each physical property value of the obtained test piece.

[0018]

[Table 1] In Table 1, the moldability (degree of sink mark) is shown by the ratio of the area of the sink mark to the entire surface area of the molded product, and ⊚:
It represents 0 to 10%, ◯: 10 to 30%, Δ: 30 to 60%, and ×: 60 to 100%. In addition, the surface condition is ∘: no gelation product on the surface, ×: a large amount of gelation product on the surface, poor moldability, and −: cannot be judged because molding is impossible.

[0019]

As is clear from Table 1, the compositions of the present invention, Examples 1 to 4, have a relatively low elastic modulus and are excellent in moldability, surface condition and low temperature impact resistance. I understand. Further, in Comparative Examples 1 and 2, since the component (c) is not blended, the rubber as the component (b) becomes a continuous phase, and in this case, a lower elastic modulus is obtained, but on the other hand, the thermoplasticity is lost. There was also a problem with recyclability. The composition of the present invention having the above-mentioned constitution is
While maintaining the thermoplasticity and moldability of PE,
Since it is possible to realize a low elastic modulus, it is possible to develop into fields that are inferior to other elastomers, and the advantage that molding with a composition that is difficult or impossible to mold by conventional methods is possible. is there. Furthermore, most of the rubbers shown in the present invention are cheaper than conventional TPEs, and the cost aspect that has hindered the spread of TPEs can be solved at the same time, which is a great contribution to the industry.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yutaka Igarashi 1-1-1, Katata, Otsu-shi, Shiga Toyobo Co., Ltd. Research Institute (72) Inventor Chisato Nonomura 2-1-1 Katata, Otsu, Shiga Toyobo Co., Ltd.

Claims (2)

[Claims] 1. A thermoplastic polyester elastomer, (b) an amorphous rubber having a reactive functional group, and (c) two or more functional groups capable of crosslinking the component (b). A compound is contained, the composition ratio of which is (a) / (b) = 5 to 95/95 to 5 (weight ratio), and the number of functional groups of the component (c) is the functional group of the component (b). The thermoplastic polyester elastomer composition is blended in an amount of 0 to 3 times equivalent to the number of the above. 2. A thermoplastic polyester elastomer, (b) an amorphous rubber having a reactive functional group, and (c) two or more functional groups capable of crosslinking the component (b). A method for producing a composition containing a compound, wherein a crosslinking reaction of the component (b) is carried out during melt mixing of the respective components, and a method for producing a thermoplastic polyester elastomer composition.