JPH0757843B2 - Rubber-like resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a rubber-like resin composition, more specifically, a polyamide resin and two specific types of rubbers mixed in a specific state. The present invention relates to a composition which can be easily molded by a method similar to that of a thermoplastic resin, has rubber-like elasticity, and has improved some of the defects of rubber, and a method for producing the same.

(Prior Art and Problems) Rubber is used in a very wide field because of its excellent elasticity and flexibility. However, in order to impart these properties to rubber, an intermolecular crosslinking step generally called vulcanization is necessary, which is one of the major causes of poor moldability of rubber.

As one of the attempts to improve this moldability, by mixing rubber and a thermoplastic resin, just like ordinary thermoplastic resin, simply by applying heat to flow, and then cooling and solidifying to a desired shape. Many proposals have been made to obtain processable rubbery compositions.

For example, Japanese Examined Patent Publication No. 55-14096 proposes an elastomer plastics composition comprising a polyamide and a crosslinked butadiene polymer, but this composition is inferior in weather resistance and ultraviolet resistance due to the butadiene polymer. However, there is a drawback that the application is limited.

In particular, JP-A-57-5753 proposes a composition made of polyamide-cured epichlorohydrin rubber, but its flexibility is not sufficient. Further, JP-A-59-49246 discloses a composition in which a polyamide, a specific nitrile rubber and a curing agent are mixed, and is disclosed in JP-A-59-168056 and JP-A-60-96630.
JP-A-60-96631 proposes a composition in which a polyamide, a specific nitrile rubber, a specific epichlorohydrin rubber, and a curing agent are mixed, but the dispersibility of the rubber is poor and the flexibility is low. , The elasticity is not enough.

The present inventors have conducted extensive studies to solve these drawbacks, and a rubber-like resin composition obtained by blending a polyamide resin with a crosslinked polyoctenylene rubber and a crosslinked EPDM is easy to mold. It has been found that the defects of rubber are improved in terms of oil resistance, weather resistance, ultraviolet resistance and the like, and that the composition has sufficient flexibility and elasticity, and such a composition can be obtained by melting the polyamide resin to form a polyoctenylene rubber. And EP
The present invention has been completed by finding that DM can be easily obtained by kneading both under the condition that both melt-crosslink.

(Means for Solving the Problem) That is, the present invention relates to a rubber-like resin composition obtained by blending a polyamide resin with a crosslinked polyoctenylene rubber and a crosslinked EPDM, and a polyamide resin with a polyoctenylene rubber.
A method for producing a rubber-like resin composition, characterized in that, when EPDM is compounded, the method includes a step of kneading the polyamide resin under a condition in which the polyamide resin melts and the polyoctenylene rubber and the butyl rubber melt-crosslink.

The polyamide resin in the present invention means caprolactam,
Lactams such as lauryl lactam, ω-aminocarboxylic acids such as 12-aminododecanoic acid and 11-aminoundecanoic acid, adipic acid and hexamethylenediamine, dodecanedioic acid and hexamethylenediamine, and dicarboxylic acids such as isophthalic acid and isophoronediamine. A resin obtained by condensation polymerization of diamine or the like is exemplified.

In addition, this polyamide resin is obtained by condensation polymerization of two or more lactams such as caprolactam and lauryllactam or hexamethylenediamine, dodecanedioic acid and isophthalic acid, ω-aminocarboxylic acid, diamine and dicarboxylic acid. It goes without saying that the copolymerized nylon mentioned above, and those called polyetheramide, polyesteramide or polyetheresteramide containing lauryllactam and tetramethylene glycol as the main components are also included.

The polyoctenylene rubber used in the present invention is obtained by dimerizing butadiene and then metathesis-polymerizing octenylene, which is a cyclic compound having one double bond left by hydrogenation. Among them, the trans content is 52 to 90
%, The crystallinity in the range of 5 to 70% is preferably used.

EPDM used in the present invention is a usual synthetic rubber obtained by copolymerization of ethylene, propylene and dienes, and various commercially available ones can be used.

Dyes and pigments, various stabilizers, fillers, plasticizers, oils and the like can be added to the polyamide resin in the present invention.
Further, the polyoctenylene rubber used in the present invention and
To EPDM, fillers such as carbon black, zinc white, magnesium oxide, stearic acid, silica, etc., oils such as extender oil, various stabilizers such as antiaging agent, lubricants and the like can be added.

The rubber-like resin composition of the present invention can be obtained by kneading under a condition in which the polyamide resin melts and the polyoctenylene rubber and EPDM crosslink while melting. In this case, the polyoctenylene rubber and EPDM can be self-crosslinked by heat, but preferably they are heated as a homogeneous mixture with a crosslinking agent or a crosslinking accelerator. Examples of the crosslinking agent include peroxides, sulfur, organic sulfides, bismaleimides, and epoxy compounds, and examples of the crosslinking accelerator include thiazoles, thiurams, guanidines, and the like. The heating temperature is preferably in the range of 150 to 270 ° C. from the viewpoint of ease of kneading, crosslinking reaction rate, and deterioration prevention.

Further, in order to efficiently carry out the crosslinking reaction, the polyoctenylene rubber or / and EPDM is preliminarily mixed with the crosslinking agent or /
It is also possible to uniformly mix the crosslinking accelerator and the like at a low temperature of 100 ° C. or lower, and then melt-mix with the polyamide resin to complete the crosslinking reaction.

The kneading of polyamide resin, polyoctenylene rubber and EPDM in the present invention is performed with a kneader such as a Banbury mixer, a roll, an extruder, etc., but in order to prevent oxidative deterioration of the resin and the rubber, the air was shut off in a nitrogen atmosphere or the like. It is more preferable to knead in the state.

The method for obtaining the composition of the present invention is characterized in that the polyoctenylene rubber and the EPDM are kneaded while being crosslinked, and preferably the kneading should be continued until the crosslinking of the rubber is almost completed. If the kneading is stopped before the progress of the step, the moldability becomes difficult due to the poor dispersibility, and at the same time, the flexibility and elasticity are not exhibited due to insufficient crosslinking.

(Effect of the invention) The rubber-like resin composition obtained in the present invention is flexible and rich in elasticity, excellent in oil resistance, chemical resistance, ozone resistance, weather resistance, ultraviolet resistance, etc. Since it can be easily molded like a plastic resin, it is used, for example, by extrusion molding to form a tube, as a wire coating, or molded into a flexible sheet. Further, it can be easily molded and used for shoes, clips, etc. by injection molding, compression molding, etc., and can also be molded by blow molding for diaphragms, bellows, etc.

(Example) Hereinafter, the present invention will be described in more detail with reference to examples.

Examples 1 to 5 Nylon 12 (Daicel Hüls, Daiamide L1940) and polyoctenylene rubber (Hüls V in the proportions shown in Table 1)
ESTENAMER8012), EPDM (JSREP manufactured by Japan Synthetic Rubber), and 2 parts by weight of metaphenylene bismaleimide, 0.2 parts by weight of lauroyl peroxide, 5 parts by weight of zinc oxide and stearic acid per 100 parts by weight of the total amount of the rubber compounded. Two parts by weight were charged into a Henschel Misser all at once, dry-blended, then extruded at 220 ° C. in a Toshiba 55 mm twin-screw extruder, and pelletized by a pelletizer. The pellets were molded into a bending test piece and an Izod test piece with a normal injection molding machine. When flexural modulus and Izod impact strength were determined using these test pieces, it was found that they showed good appearance and physical properties. Furthermore, using these bending test pieces,
℃, 50ppm ozone, 60mm between chucks 3
Dynamic elongation was performed with a stroke of 0 to 5 mm in a cycle of 0 rpm, the time until the sample broke was measured, and this value was taken as the ozone resistance value. The results are shown in Table 1.

Example 6 Nylon 6 in the ratio shown in Table 1 (Amylan CM102 manufactured by Toray Industries, Inc.
1), polyoctenylene rubber and EPDM, 5 parts by weight of metaphenylene bismaleimide and 0.5 parts by weight of benzothiazole disulfide per 100 parts by weight of the total amount of the rubber compounded, and a rhecode manufactured by HAAKE set at 250 ° C. The kneading was performed by setting the rotor rotation speed of the Leo cord to 50 rpm. When observing the torque meter attached to the Leo cord, the torque gradually increased after the kneading started,
The maximum value was shown in 5 to 10 minutes. After the torque reached the maximum, the kneading was continued for about 8 minutes to sufficiently carry out the crosslinking reaction, and then the content was taken out. When this reaction product was press-molded, a sheet could be molded as easily as a thermoplastic resin. Bending test pieces and Izod test pieces were punched out from this sheet, and the flexural modulus and Izod impact strength were determined. As a result, it was found that good physical properties were exhibited. Further, ozone resistance was measured using these bending test pieces. The results are shown in Table 1.

Examples 7 and 8 In Experimental Examples 1 to 5, instead of nylon 12, nylon 612 (Daiamide D180 manufactured by Daicel Hüls) was used.
Example 1 except that 0) and polyamide elastomer (Daiamide PAE E40 manufactured by Daicel Hüls) are used.
Kneading and molding are carried out in the same manner as described above to obtain a flexural modulus,
Izod impact strength and ozone resistance were determined. The results are shown in Table 1.
Shown in.

Example 9 Polyoctenylene rubber in the proportions shown in Table 1 (VE made by Huls
After dry blending STENAMER6213) and EPDM with 5 parts by weight of metaphenylene bismaleimide and 0.5 parts by weight of lauroyl peroxide and zinc oxide per 100 parts by weight of the rubber compounded in a Henschel mixer. Nylon of this pellet was kneaded in a Chuo Kikai 30mm twin screw extruder at 60 ° C and pelletized with a pelletizer.
12 and 220% in a 55 mm twin-screw extruder.
After kneading and sufficient crosslinking reaction, pelletized with a pelletizer. This pellet was molded into a bending test piece and an Izod test piece with a usual injection molding machine. Using these test pieces, flexural modulus, Izod impact strength, and ozone resistance were determined. The results are shown in Table 1.

Comparative Examples 1 to 3 Using the three types of rubbers shown in Table 1, a bald test piece and an Izod test piece were molded by an injection molding machine. Using these test pieces, flexural modulus, Izod impact strength, and ozone resistance were determined. The results are shown in Table 1. It was revealed that all of these rubbers had poor ozone resistance.

Comparative Examples 4 to 6 In Examples 1 to 5, as shown in Table 1, using only one kind of three kinds of rubber, kneading and molding in exactly the same manner as in Examples 1 to 5, flexural modulus, Izod Impact strength and ozone resistance were calculated. The results are shown in Table 1. It was revealed that all of these rubbers had poor ozone resistance.

Claims (2)

[Claims] 1. A rubber-like resin composition comprising a polyamide resin and crosslinked polyoctenylene rubber and crosslinked EPDM. 2. A polyamide resin containing polyoctenylene rubber
A method for producing a rubber-like resin composition, characterized in that, when compounding EPDM, the method comprises a step of kneading under a condition in which the polyamide resin melts and the polyoctenylene rubber and the EPDM melt-crosslink.