JP3502249B2 - Shape-memory resin molding having impact resistance - Google Patents

Description

Detailed Description of the Invention

[0001]

INDUSTRIAL APPLICABILITY The present invention is useful for various applications such as vehicle materials, mechanical materials, electric materials, architectural gap fillers, medical materials, decorative materials, medical materials, etc., and has a glass transition temperature of room temperature or higher. In addition, the present invention relates to a resin molded product having a shape memory property at room temperature or higher and good impact resistance.

[0002]

2. Description of the Related Art As one of shape memory resins, Japanese Patent Laid-Open No.
A polynorbornene having a molecular weight of 1,000,000 or more described in JP-A-1-188444 is known. Polynorbornene has a problem that the glass transition temperature is constant and the temperature at which the shape memory property of the molded body is exerted cannot be changed. Also, when used, the production of molded articles is limited to compression molding,
Processing time is long due to the need for cross-linking during molding, and the molded body has the drawback that it cannot be reused because it is cross-linked. On the other hand, JP-A-61-293
Molded articles made of polyurethane resin described in Japanese Patent Publication No. 214, Japanese Patent Application Laid-Open No. 1-264829, etc. have an advantage that shape memory properties can be exhibited at various temperatures by freely changing the glass transition temperature of the polyurethane resin. . Further, it is not necessary to crosslink, and the molded body can be reused.

[0003]

However, a molded article made of a polyurethane resin having a shape memory property at room temperature has a glass transition temperature higher than room temperature and thus has a low impact resistance and elongation, and therefore becomes brittle and becomes difficult to be deformed. It is likely to be cracked and poor in practicality. Therefore, an object of the present invention is to provide a shape-memory molded article having impact resistance at room temperature, which solves the above-mentioned problems of the prior art.

[0004]

The above object can be achieved by the present invention described below. That is, the present invention includes at least a resin component and the elastomer component, the temperature range below or above room temperature and room temperature, respectively have at least one glass transition temperature, glass transition temperature and room Not temperature range above room temperature
The shape-memory resin molded product is characterized in that the difference in glass transition temperature in the full temperature range is 20 to 220 ° C.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to the preferred embodiments. The resin component constituting the molded product of the present invention is a polymer having a glass transition temperature in a temperature range of room temperature or higher, and a known polyurethane resin can be used. A preferred polyurethane resin is one obtained by reacting a polyol, a polyisocyanate and, if necessary, a chain extender with a glass transition temperature of room temperature or higher, and a polyester type polyurethane resin,
Examples thereof include polyether type polyurethane resin, polyester polyether type polyurethane resin, polycarbonate type polyurethane resin, and polycaprolactone type polyurethane resin. The glass transition temperature of polyurethane resin is
It is preferably in the range of 20 to 150 ° C. If the glass transition temperature is lower than 20 ° C, shape memory cannot be imparted to the molded product at room temperature or higher, and if it exceeds 150 ° C, the polyurethane resin and the elastomer having a glass transition temperature in the temperature range lower than room temperature are melted. Kneading becomes difficult. The glass transition temperature of the polyurethane resin is more preferably 35 to 100.
℃.

The elastomer component constituting the molded article of the present invention is a polymer having a glass transition temperature in a temperature range below room temperature, and known elastomers can be used. Preferred elastomers include nitrile rubber, thermoplastic polyester elastomers, thermoplastic polyamide elastomers, styrene-butadiene-styrene (SB
S) elastomers, styrene-ethylene butylene-styrene (SEBS) elastomers, styrene-isoprene-styrene (SIS) elastomers, styrene-ethylene propylene-styrene (SEPS) elastomers, chlorinated polyethylene and the like.

[0007] More preferable elastomers include conventionally known nitrile rubbers which are uncrosslinked or partially crosslinked to the extent that they have fluidity, and modified nitrile rubbers such as carboxy-modified NBR and hydrogenated NBR. Nitrile rubber is a copolymer rubber of an unsaturated nitrile compound such as acrylonitrile or methacrylonitrile and a conjugated diene such as butadiene or isoprene. Specifically, acrylonitrile-butadiene copolymer rubber (NBR), acrylonitrile-isoprene copolymer rubber (NIR), acrylonitrile-butadiene-isoprene copolymer rubber (NBI).
R) and the like. Partially crosslinked nitrile rubber is obtained by copolymerizing a polyfunctional monomer such as divinylbenzene as a component of the above nitrile rubber, and a carboxy-modified nitrile rubber is obtained by using acrylic acid or a part of conjugated diene units in the nitrile rubber. The hydrogenated nitrile rubber is obtained by substituting an unsaturated carboxylic acid such as methacrylic acid, and the conjugated diene unit in the nitrile rubber is hydrogenated.

The content of the unsaturated nitrile compound in the nitrile rubber is preferably 10 to 55% by weight, and when the content of the unsaturated nitrile compound is less than 10% by weight, the compatibility with the polyurethane resin is poor, and , 55% by weight, the nitrile rubber becomes hard and the resulting shape memory composition has low impact resistance and tensile elongation. The more preferable content of the unsaturated nitrile compound is 25 to 45% by weight.

The preferred glass transition temperature of the elastomeric component is in the range of -70 ° C to less than 20 ° C. When the glass transition temperature is 20 ° C. or higher, the impact resistance of the molded product is not improved, and those having a temperature of −70 ° C. or lower are difficult to obtain. The difference between the glass transition temperature of the resin component and the glass transition temperature of the elastomer component is preferably in the range of 20 ° C to 220 ° C. If this difference is less than 20 ° C, the impact resistance of the molded article is not improved, and if it exceeds 220 ° C, melt-kneading is difficult.

The ratio of the resin component and the elastomer component used is preferably in the range of 1 to 100 parts by weight based on 100 parts by weight of the resin component. When the proportion of the elastomer component is less than 1 part by weight, the impact resistance and tensile elongation of the obtained shape memory resin molded product are small, and when it exceeds 100 parts by weight, the shape memory resin molded product has a weak shape memory property around room temperature. It is not preferable. A more preferable ratio of the elastomer component is in the range of 10 to 90 parts by weight.

In order to obtain a molded article of the present invention containing the above resin component and elastomer component as polymer components, these polymer components are first mixed with, for example, a mixing roll, a Banbury mixer, a kneader, a single screw, a twin screw, or the like. Melt kneading with an extruder or the like. At that time, an effective amount of any additive such as a colorant, a filler, a conductive agent, an antistatic agent, a dispersant and the like can be used within a range not hindering the achievement of the object of the present invention. Furthermore, during melt kneading, the elastomer component can be dynamically vulcanized (crosslinked) by using a conventionally known vulcanizing (crosslinking) agent, and the above mixture can be molded by a conventionally known method such as an injection molding machine or an extrusion molding machine. The molded product of the present invention is obtained by molding using a machine. This molded product is a shape memory molded product having at least one glass transition temperature in a temperature range of room temperature or higher and at least one glass transition temperature in a temperature range lower than room temperature, and having good impact resistance at room temperature. .

[0012]

EXAMPLES The present invention will be described in more detail below with reference to examples. In addition, unless otherwise specified, "parts" and "%" in the text are based on weight.

Example 1 Polytetramethylene ether glycol having an average molecular weight of about 250 (Poly THF 250 manufactured by BASF, Germany)
1,000 parts of 1,4 butanediol 100 parts and 4,
1300 parts of 4'diphenylmethane diisocyanate
The reaction was carried out at 00 ° C to obtain a polyurethane resin (U1) having a glass transition temperature of about 45 ° C. This polyurethane resin (U
1) 100 parts of nitrile rubber (N1) (JSR nitrile rubber PN20HA manufactured by Japan Synthetic Rubber Co., Ltd.) was blended with 20 parts, and then melt-kneaded into pellets by an extruder, and a flat plate of the present invention was formed using an injection molding machine. A shape memory molded body was obtained.

The glass transition temperature of this shape memory molded article was measured according to JIS K7121, and the mechanical properties were measured according to JIS K7311 using a test piece prepared from a flat plate. Impact resistance is measured according to JIS K7110,
Samples that did not break in the Izod impact test were designated as NB in the table. The shape memory property was evaluated by the following method. The above results are shown in Table 1. These test methods are the same in the following examples and comparative examples.

Shape memory at room temperature ◯: When a molded product (injection plate having a thickness of 2 mm) is bent in an atmosphere of 20 to 40 ° C., the bent shape is retained, and when it is further immersed in water at 80 ° C. or more, the shape is maintained. Returns to the original planar shape x: When the molded product (2 mm thick injection plate) is bent in an atmosphere of 20 to 40 ° C., the bent shape is not retained. Alternatively, even if the shape is retained, it cannot be returned to its original flat shape by being immersed in water at 80 ° C or higher.

Examples 2 and 3 The resin molding of the present invention was carried out in the same manner as in Example 1 except that the usage ratio of the polyurethane resin (U1) and the nitrile rubber (N1) in Example 1 was changed as shown in Table 1. Got the body The physical properties of the obtained molded product were measured and the performance was evaluated, and the results shown in Table 1 were obtained.

Example 4 100 parts of the polyurethane resin (U1) and partially crosslinked nitrile rubber (N2) in Example 1 (Nip manufactured by Zeon Corporation)
ol DN216) 20 parts, a resin molded product of the present invention was obtained in the same manner as in Example 1. The physical properties of the obtained molded product were measured and the performance was evaluated, and the results shown in Table 1 were obtained.

Example 5 1000 parts of bisphenol A-polypropylene glycol copolymer (BPX-33 manufactured by Asahi Denka Kogyo Co., Ltd.) having an average molecular weight of about 580 and having hydroxyl groups at both ends, and polytetramethylene ether having an average molecular weight of about 2000. 200 parts of glycol (Poly THF 2000 manufactured by BASF, Germany),
180 parts of 1,4 butanediol and 975 parts of 4,4 ′ diphenylmethane diisocyanate are reacted at 100 ° C. to obtain a polyurethane resin (U having a glass transition temperature of about 60 ° C.
2) was obtained. From 100 parts of this polyurethane resin (U2) and 20 parts of nitrile rubber (N1), a resin molded product of the present invention was obtained in the same manner as in Example 1. The physical properties of the obtained molded product were measured and the performance was evaluated, and the results shown in Table 1 were obtained.

Example 6 100 parts of the polyurethane resin (U1) and styrene-butadiene-styrene (SBS) elastomer (S1) in Example 1 (Europrene SOL T manufactured by Enchem Co., Ltd.)
161) From 20 parts, a resin molded product of the present invention was obtained in the same manner as in Example 1. The physical properties of the obtained molded product were measured and the performance was evaluated. The results are shown in Table 1.

Example 7 100 parts of the polyurethane resin (U1) in Example 1 and styrene-ethylenebutylene-styrene (SEBS) elastomer (S2) (Tuftec M manufactured by Asahi Kasei Corporation)
1943) and 20 parts to obtain a resin molded product of the present invention in the same manner as in Example 1. The physical properties of the obtained molded product were measured and the performance was evaluated. The results are shown in Table 1.

Example 8 100 parts of the polyurethane resin (U1) in Example 1 and styrene-ethylene propylene-styrene (SEPS)
Elastomer (S3) (Kuraray Septon 204
3) From 20 parts, a resin molded product of the present invention was obtained in the same manner as in Example 1. The physical properties of the obtained molded product were measured and the performance was evaluated, and the results shown in Table 1 were obtained.

Comparative Example 1 A resin molded product of the present invention was obtained in the same manner as in Example 1 from the polyurethane resin (U1) alone. The physical properties of the obtained molded product were measured and the performance was evaluated, and the results shown in Table 2 were obtained.

Comparative Example 2 100 parts of polyurethane resin (U1) and nitrile rubber (N
1) From 200 parts, a resin molded product of the present invention was obtained in the same manner as in Example 1. The physical properties of the obtained molded product were measured and the performance was evaluated, and the results shown in Table 2 were obtained.

Comparative Example 3 A resin molded product of the present invention was obtained in the same manner as in Example 1 from the polyurethane resin (U2) alone. The physical properties of the obtained molded product were measured and the performance was evaluated, and the results shown in Table 2 were obtained.

[0025]

[Table 1] (Note) Tg1: glass transition temperature derived from polyurethane resin Tg2: glass transition temperature derived from elastomer component

[0026]

[Table 2]

The results shown in Table 1 indicate that the molded articles of Examples 1 to 8 of the present invention have glass transition temperatures below room temperature and below room temperature, and have a tensile elongation of 200% or more at room temperature and impact resistance. It is shown that it is a tough shape-memory molded product that also has properties. On the other hand, the results of Table 2 show that Comparative Examples 1 and 3
The polyurethane resin (U1, U2) -only molded product containing no elastomer component shown in FIG. 1 has a shape memory property at room temperature, but does not have a glass transition temperature in a temperature range below room temperature and has small elongation and impact strength. , Is poor in practicality as a shape memory material. The molded product of Comparative Example 2 has a glass transition temperature in a temperature range of room temperature or higher and a temperature range of lower than room temperature, but the usage ratio of the nitrile rubber exceeds the range of the present invention, and the elongation and impact strength are large. However, it is inferior in shape memory property at room temperature, indicating that it is unsuitable as a shape memory material.

[0028]

According to the present invention as described above, a vehicle material,
Mechanical materials, electrical materials, gap filling materials for construction, medical materials,
It is useful for various uses such as a decorative material and a medical material, and has a glass transition temperature of room temperature or higher, has shape memory property at room temperature or higher, and has a good impact resistance at room temperature.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Koike 1-7-6 Nihonbashi Bakurocho, Chuo-ku, Tokyo Within Dainichi Seika Industries Co., Ltd. (72) Hirofumi Nishimura 1-7-6 Nihonbashi-Bakurocho, Chuo-ku, Tokyo Dainichi Seika Kogyo Co., Ltd. (72) Inventor Susumu Nakamura 1-7-6 Nihonbashi Bakurocho, Chuo-ku, Tokyo Inside Dainichi Seika Kogyo Co., Ltd. (56) Reference JP-A-11-140304 (JP, A) Flat 6-65460 (JP, A) JP 4-122760 (JP, A) JP 4-342762 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C08J 5 / 00 C08L 7/00-101/16

Claims (2)

(57) [Claims] And a method according to claim 1, wherein at least the resin component and the elastomer component, to a temperature range above and below room temperature at room temperature, each have at least one glass transition temperature, above room temperature
Glass transition temperature in the temperature range and glass transition in the temperature range below room temperature
Shape-memory resin molded difference in temperature, characterized in 20 to 220 ° C. der Rukoto. 2. The shape-memory resin molded product according to claim 1, wherein the resin component is a polyurethane resin.