JP2011178939A - Norbornene-based polymer molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a norbornene-based polymer molded product having excellent kneading properties and moldability and the glass transition temperature controlled so as to exhibit shape memorizing properties at a desired temperature. <P>SOLUTION: The norbornene-based polymer molded product is produced by cross-linking a norbornene-based polymer composition containing a norbornene-based polymer, a plasticizer, and a reactive compound which contributes to a radical cross-linking reaction of the norbornene-based polymer, and is a liquid during kneading with the norbornene-based polymer in which at least one thereof is tri- or higher functional. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a norbornene polymer molded product obtained by crosslinking a norbornene polymer known as a shape memory resin.

  Norbornene-based polymers are known as shape memory resins. That is, when the norbornene-based polymer is deformed above the glass transition temperature and then cooled below the glass transition temperature, the deformation is fixed. Further, the original shape is restored by heating again to the glass transition temperature or higher. However, the molecular weight of the norbornene polymer is extremely large. Therefore, in the case of a norbornene-based polymer alone, the fluidity is poor even at the glass transition temperature or higher, and the molding method is limited. In addition, when a norbornene polymer powder is kneaded, the particles are difficult to fuse with each other.

  On the other hand, norbornene-based polymers absorb a large amount of oil. For this reason, fluidity | liquidity and a moldability can be improved by mix | blending an oil component with a norbornene-type polymer. For example, Patent Documents 1 to 3 disclose norbornene-based polymer compositions in which various resins are blended to improve fluidity and moldability. Patent Document 4 discloses a cross-linked polymer obtained by polymerizing norbornene and a cyclic olefin compound having two strained cyclic olefin groups having metathesis polymerizability similar to norbornene in the presence of a metathesis polymerization catalyst system. A coalesced molding is disclosed.

JP-A-5-58026 Japanese Unexamined Patent Publication No. 63-54460 JP-A-2-22354 JP-A-2-255830

  When an oil component is blended with a norbornene polymer, fluidity and moldability are improved. However, when an oil component is blended, the glass transition temperature is lowered. For this reason, shape memory property cannot be utilized in a practical temperature range. In addition, as described in Patent Documents 1 to 3, when other resins are blended, it is necessary to consider compatibility with the norbornene-based polymer. In addition, the crosslinked polymer molded product described in Patent Document 4 has an increased glass transition temperature as compared with a norbornene-based polymer alone, but the production method is complicated.

  The present invention has been made in view of such circumstances, and is a norbornene-based polymer whose glass transition temperature is controlled so as to be excellent in kneadability and moldability and to exhibit shape memory at a desired temperature. It is an object to provide a molded body.

  (1) The norbornene-based polymer molded article of the present invention contributes to a radical crosslinking reaction of a norbornene-based polymer, a plasticizer, and the norbornene-based polymer, and is liquid when kneaded with the norbornene-based polymer, and at least one kind is A norbornene-based polymer composition containing a trifunctional or more reactive compound is crosslinked.

  The norbornene-based polymer composition in the present invention contains a plasticizer. Thereby, the fluidity | liquidity of a norbornene-type polymer composition improves, and a kneadability and a moldability improve. Further, the norbornene polymer molded body of the present invention is crosslinked. By introducing a three-dimensional network structure by crosslinking, the glass transition temperature (hereinafter referred to as “Tg”) increases. That is, according to the norbornene-based polymer molded article of the present invention, the decrease in Tg due to the blending of the plasticizer is compensated by the introduction of the crosslinked structure. Therefore, the norbornene-based polymer molded article of the present invention is excellent in kneadability and moldability and has a desired Tg.

  The norbornene polymer molded product of the present invention is produced by radical crosslinking of a norbornene polymer composition. In the radical crosslinking reaction, a reactive compound that is liquid at the time of kneading with the norbornene-based polymer and at least one of which is trifunctional or higher is used. The reactive compound is liquid when kneaded with the norbornene-based polymer. For this reason, at the time of kneading with a norbornene-based polymer, it plays a role as a processing aid and improves kneadability and moldability. The reactive compound used may be one kind or two or more kinds. Among these, at least one kind is trifunctional or more. Thereby, a three-dimensional network structure can be introduced efficiently and Tg can be improved even with a small amount.

  For example, when a large amount of a reactive compound is blended and the crosslinking density becomes too high, the change in hardness with respect to the temperature of the norbornene-based polymer molded product, that is, the change between the rubber elastic state and the solidified state with Tg as a boundary. Become sluggish. If it becomes like this, shape memory property will become difficult to express. In this respect, according to the norbornene-based polymer molded article of the present invention, Tg can be increased only by blending a relatively small amount of the reactive compound. Therefore, the expression of shape memory property is not easily impaired.

  In addition, the norbornene-based polymer composition in the present invention is excellent in kneadability. For this reason, it becomes possible to mix | blend additives, such as a electrically conductive agent. When a conductive agent is blended, conductivity can be imparted to the norbornene-based polymer molded body. Thereby, for example, it is possible to change the shape by energizing the norbornene polymer molded body and changing the temperature.

  Hereinafter, embodiments of the norbornene polymer molded body of the present invention will be described. The norbornene-based polymer molded article of the present invention is not limited to the following embodiments, and can be variously modified and improved by those skilled in the art without departing from the gist of the present invention. Can be implemented.

  The norbornene polymer molded article of the present invention is obtained by crosslinking a norbornene polymer composition containing a norbornene polymer, a plasticizer, and a reactive compound. The norbornene-based polymer can be obtained by ring-opening polymerization of norbornene obtained by Diels-Alder reaction of cyclopentadiene with ethylene, propylene, ethylene or the like. A typical norbornene-based polymer includes a ring-opening polymer of bicyclo (2,2,1) heptene-2.

  What is necessary is just to use what is generally used for rubber | gum as a plasticizer. For example, ester plasticizers such as dioctyl phthalate, dibutyl phthalate, di-2-ethylhexyl phthalate, dioctyl sebacate, dioctyl adipate, polypropylene adipate, tricresyl phosphate, paraffinic, naphthenic, aromatic process oil, stearin Examples include vegetable oils such as acid and soybean oil.

  What is necessary is just to determine the compounding quantity of a plasticizer in consideration of kneadability and moldability. For example, 10 parts by mass or more is desirable with respect to 100 parts by mass of the norbornene-based polymer. It is more preferable that it is 20 parts by mass or more. As the amount of the plasticizer is increased, the kneadability and moldability are improved, but Tg is lowered. For this reason, it is necessary to increase the compounding quantity of the reactive compound mentioned later. When the compounding amount of the reactive compound is too large, the change between the rubber elastic state and the solidified state with Tg as a boundary in the norbornene-based polymer molded product becomes slow. As a result, it becomes difficult to express shape memory properties. Therefore, if the desired kneadability and moldability are obtained, the amount of plasticizer should be as small as possible. From such a viewpoint, the compounding amount of the plasticizer is desirably 40 parts by mass or less with respect to 100 parts by mass of the norbornene-based polymer. It is more preferable that it is 30 parts by mass or less.

  The reactive compound contributes to the radical crosslinking reaction of the norbornene-based polymer, and includes a crosslinking agent, a co-crosslinking agent, a crosslinking assistant, an organic peroxide marketed as a crosslinking accelerator, an ultraviolet curable monomer, and the like. It is. The reactive compound needs to be in a liquid state when kneaded with the norbornene-based polymer. The kneading of the norbornene polymer and the reactive compound is often performed at a temperature of 60 to 80 ° C. For this reason, as the reactive compound, a liquid compound at room temperature or a compound having a melting point of 80 ° C. or lower may be selected. Moreover, as a reactive compound, 1 type may be used independently and 2 or more types may be mixed and used. However, at least one of them uses a trifunctional or higher functional compound.

  Suitable organic peroxides having a freezing point of −20 ° C. or lower (liquid at room temperature) suitable as reactive compounds include t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate. Ate, t-amyl peroxybenzoate, t-butyl peroxybenzoate, n-butyl 4,4-di (t-butylperoxy) valerate, ethyl 3,3-di (t-butylperoxy) butyrate, 2, Examples include 5-dimethyl-2,5-di (t-butylperoxy) hexane, di-t-butylperoxide, dimethyl-2,5-di (t-butylperoxy) hexyne-3, and the like. Examples of organic peroxides that are solid at room temperature but have a melting point of 80 ° C. or lower include 1,3 di (2-t-butylperoxyisopropyl) benzene.

  Moreover, as a trifunctional compound suitable as a reactive compound and liquid at room temperature, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, ethoxylated isocyanuric acid triacrylate, ε-caprolactone modified tris- (2-acryloxyethyl) ) Isocyanurate, ethoxylated glyceryl triacrylate, pentaerythritol triacrylate, ditrimethylolpropane tetraacrylate, ethoxylated pentaerythritol tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol polyacrylate, dipentaerythritol hexaacrylate, trisacryloyloxyethyl phosphate , Triallyl cyanurate, triallyl isocyanurate, etc.

  What is necessary is just to determine the compounding quantity of a reactive compound in consideration of the compounding quantity and Tg of a plasticizer. For example, in order to set Tg to 35 ° C. or higher, the compounding amount of the reactive compound is desirably 10 parts by mass or more with respect to 100 parts by mass of the norbornene-based polymer. Moreover, in order to make Tg 45 degrees C or less, it is desirable that it is 30 mass parts or less.

  The Tg of the norbornene-based polymer molded product of the present invention can be appropriately set by adjusting the type of the reactive compound, the blending amount, the crosslinking conditions, and the like. Therefore, an optimal Tg may be set according to the application. For example, when Tg is set to 35 ° C. or higher and 45 ° C. or lower, which is slightly higher than room temperature, it is practical because less energy is required to develop shape memory properties. In the present specification, the peak temperature appearing in the curve of the loss elastic modulus E ″ with respect to the temperature obtained by measuring dynamic viscoelasticity is adopted as Tg.

  In addition to the plasticizer and the reactive compound, additives such as an antiaging agent, a reinforcing agent, and a coloring agent may be added to the norbornene-based polymer composition as necessary. In particular, when a conductive agent is blended, conductivity can be imparted to the norbornene-based polymer molded body. Thereby, for example, the shape can be changed by energizing the norbornene-based polymer molded body and changing the temperature. As the conductive agent, for example, conductive fine particles such as a carbon material or a metal may be used. For example, it is desirable to use a carbon material because it is relatively inexpensive and it is easy to form a conductive path. As the carbon material, for example, carbon black having excellent conductivity, such as ketjen black, is preferable because of its small particle size and easy aggregation.

  The norbornene-based polymer molded product of the present invention can be produced, for example, as follows. First, a norbornene-based polymer, a plasticizer, and, if necessary, additives such as a conductive agent are kneaded with a kneader such as a kneader or Banbury while heating to a predetermined temperature. Next, after reducing the temperature of the kneaded product to a predetermined temperature, the reactive compound is added to the kneaded product. And kneading | mixing with a two-roll etc. prepares a norbornene-type polymer composition. In this state, the reactive compound is liquid. Thereafter, the prepared norbornene-based polymer composition is filled in a mold and crosslinked by press molding under predetermined conditions. In addition, what is necessary is just to determine a crosslinking method suitably according to the kind of reactive compound.

  Next, the present invention will be described more specifically with reference to examples.

<Manufacture of norbornene-based polymer moldings>
[Examples 1 to 3]
From the raw materials shown in Table 1 below, norbornene-based polymer molded bodies of Examples 1 to 3 were produced. First, a plasticizer paraffin-based process oil (“Diana (registered trademark) process oil NM280” manufactured by Idemitsu Kosan Co., Ltd.) is added to a norbornene-based polymer (“NOSOLEX NS” manufactured by Astrotech Co., Ltd.), and about 160 ° C. Below, it knead | mixed with the kneader. In Examples 2 and 3, the conductive agent Ketjen Black (“Ketjen Black EC300J” manufactured by Ketjen Black International Co., Ltd.) was also added and kneaded. Next, the kneaded product was taken out from the kneader, and after the temperature of the kneaded product was lowered to 60 to 70 ° C., three kinds of reactive compounds (A) to (C) were added, and kneaded with two rolls. The obtained norbornene-based polymer composition was filled in a mold and cross-linked by press molding at 170 ° C. The reactive compounds (A) to (C) used are as follows.
Reactive compound (A): 1,3 di (2-t-butylperoxyisopropyl) benzene (“Perbutyl (registered trademark) P” manufactured by NOF Corporation)
Reactive compound (B): triallyl isocyanurate (“TAIC (registered trademark)” manufactured by Nippon Kasei Co., Ltd.)
Reactive compound (C): Trimethylolpropane trimethacrylate (“Hi-Cross M” manufactured by Seiko Chemical Co., Ltd.)
[Comparative Example 1]
Only the norbornene-based polymer used in Examples 1 to 3 above was kneaded with a kneader at about 160 ° C., then filled in a mold, and press-molded at 170 ° C.

[Comparative Examples 2 to 4]
A norbornene-based polymer composition was prepared in the same manner as in Example 1 except that no reactive compound was added. Thereafter, the prepared norbornene-based polymer composition was filled in a mold and press-molded. At this time, the molding temperature was set to 170 ° C. for Comparative Example 2, and the molding temperature was set to 200 ° C. for Comparative Examples 3 and 4.

[Comparative Examples 5 to 7]
Instead of the reactive compound, sulfur and a vulcanization accelerator were blended to produce a norbornene polymer molded body. First, the vulcanization accelerator (a) was added to the same norbornene polymer and plasticizer as in the above examples, and the mixture was kneaded at about 160 ° C. with a kneader. Next, after taking out the kneaded material from the kneader and lowering the temperature of the kneaded material to 60 to 70 ° C., sulfur (manufactured by Tsurumi Chemical Co., Ltd.) and vulcanization accelerators (b) to (d) are added. And kneaded with two rolls. The obtained norbornene-based polymer composition was filled in a mold and cross-linked by press molding at 170 ° C. The used vulcanization accelerators (a) to (d) are as follows.
Vulcanization accelerator (a): 2 types of zinc oxide (Mitsui Metal Mining Co., Ltd.)
Vulcanization accelerator (b): Tetraethylthiuram disulfide ("Noxer (registered trademark) TET" manufactured by Ouchi Shinsei Chemical Co., Ltd.)
Vulcanization accelerator (c): Tellurium diethyldithiocarbamate (“Axel (registered trademark) TL-PT” manufactured by Kawaguchi Chemical Industry Co., Ltd.)
Vulcanization accelerator (d): di-2-benzothiazolyl disulfide (“Noxeller DM” manufactured by Ouchi Shinsei Chemical Co., Ltd.)
[Comparative Example 8]
In place of the norbornene-based polymer, a urethane polymer molded body was produced by a casting method using a liquid urethane polymer ("Diary MP5510" manufactured by Diaplex). The molding temperature was 140 ° C.

Table 1 shows the raw materials used, their blending amounts, and molding methods. Moreover, the evaluation result mentioned later is also shown collectively.

<Evaluation method>
[Kneadability]
For Example 1, the kneadability was evaluated when the norbornene polymer and the plasticizer were kneaded, and for Examples 2 and 3, the conductive agent was further blended and kneaded. For Comparative Example 1, only the norbornene polymer was kneaded. For Comparative Examples 2 to 4, when the norbornene polymer and the plasticizer were kneaded, for Comparative Examples 5 to 7, further vulcanization accelerators were used. The kneadability when the two types of zinc oxide (a) were blended and kneaded was evaluated. The evaluation was performed by visually observing the kneaded state. The dispersion state of the raw materials is good and the kneaded product is in a good state (indicated by a circle in Table 1), and the raw material dispersion state is poor and the kneaded material is not in a cohesive state (in Table 1 × Marked with a mark).

[Formability]
The moldability of the manufactured norbornene polymer molded body and urethane polymer molded body was evaluated. Evaluation was performed by visually observing each molded body. The case where there was no void and it was formed into a uniform sheet shape was good (indicated by a circle in Table 1), and the case where a void was mixed or could not be formed into a sheet shape was bad (in Table 1 x Marked with a mark).

[Volume resistivity]
The volume resistivity of the manufactured norbornene-based polymer molded body and urethane polymer molded body was measured according to JIS K6271 (2008). The measurement was performed by applying a DC voltage of 100V.

[Glass-transition temperature]
Tg of the produced norbornene-based polymer molded body and urethane polymer molded body was measured using a longitudinal vibration type dynamic viscoelasticity measuring apparatus (“Rheogel-E4000” manufactured by UBM). The peak temperature appearing in the obtained loss elastic modulus E ″ curve was defined as Tg.

[Shape controllability]
Based on the measured Tg value, the shape controllability of each molded body was evaluated. Evaluation was made good when Tg was 35 ° C. or higher and 45 ° C. or lower (indicated by a circle in Table 1), and otherwise poor (indicated by a cross in Table 1).

<Evaluation results>
As shown in Table 1, in Examples 1 to 3, both the kneadability and the moldability were good. In particular, in Examples 2 and 3, the conductive agent was also dispersed substantially uniformly. And about the molded object of Example 2, 3, the volume resistivity became small. Thereby, it was confirmed that the molded object of Example 2, 3 has electroconductivity. Moreover, Tg of the molded bodies of Examples 1 to 3 was in the range of 35 ° C. or higher and 45 ° C. or lower. That is, the shape controllability was also good for the molded bodies of Examples 1 to 3.

  On the other hand, in Comparative Example 1 in which only the norbornene-based polymer was kneaded, the polymer particles were difficult to fuse and did not form a kneaded product. Therefore, it could not be formed into a sheet. Also, in Comparative Example 2, the kneadability was not improved. This is presumably because the amount of the plasticizer is small. About Comparative Examples 3 and 4 in which the blending amount of the plasticizer was increased, the kneadability and moldability were good. However, since the blending amount of the plasticizer was increased, Tg was rapidly decreased and the shape controllability became poor.

  Moreover, about the comparative examples 5-7, the kneadability was favorable. However, sulfur and vulcanization accelerators (a) to (d) are not trifunctional or higher functional compounds. Therefore, compared with a reactive compound, a three-dimensional network structure cannot be efficiently introduced by crosslinking. For this reason, the Tg of the molded body of Comparative Example 5 was low. Moreover, sulfur and vulcanization accelerators (b) to (d) are not liquid during kneading. Therefore, when the compounding amount of sulfur was increased in order to increase Tg, the moldability decreased as in the molded body of Comparative Example 6. Furthermore, when the compounding amount of the plasticizer was increased in order to improve moldability, the Tg decreased again as in the molded body of Comparative Example 7. Thus, about the molded object of Comparative Examples 5-7 which mix | blended sulfur and the vulcanization accelerator (a)-(d), it was not able to make moldability and Tg compatible.

  Moreover, about the urethane polymer molded object of the comparative example 8, Tg was high and shape controllability was unsatisfactory.

  From the above, it was confirmed that the norbornene-based polymer molded product of the present invention has a Tg that is excellent in kneadability and moldability and that can exhibit shape memory at a practical temperature.

  According to the norbornene-based polymer molded article of the present invention, the deformation can be fixed by being deformed at a temperature higher than Tg and then cooled to a temperature equal to or lower than Tg. And if it heats to temperature higher than Tg again, it can be made to recover to the shape before a deformation | transformation. For example, if the Tg of the norbornene-based polymer molded body of the present invention is set in the range of 35 ° C. or higher and 45 ° C. or lower, the shape can be controlled in a temperature range slightly higher than room temperature, and thus the practicality is high. The norbornene-based polymer molded product of the present invention is suitable for, for example, a care assist device, a toy, a doll, artificial flowers, a thermal sensor, and various molding materials.

Claims (7)

  Norbornene comprising a norbornene-based polymer, a plasticizer, and a reactive compound that contributes to radical crosslinking reaction of the norbornene-based polymer and is liquid when kneaded with the norbornene-based polymer and at least one of which is trifunctional or higher A norbornene-based polymer molded article obtained by crosslinking a polymer-based polymer composition.   The norbornene-based polymer molded article according to claim 1, wherein the reactive compound includes a trifunctional compound that is liquid at room temperature.   The norbornene-based polymer molded article according to claim 1 or 2, wherein the reactive compound contains an organic peroxide having a melting point of 80 ° C or lower.   The compounding quantity of the said reactive compound in the said norbornene-type polymer composition is 10 to 30 mass parts with respect to 100 mass parts of the said norbornene-type polymer. Norbornene polymer molded product.   The blending amount of the plasticizer in the norbornene-based polymer composition is 20 parts by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the norbornene-based polymer. Norbornene polymer molding.   The norbornene-based polymer molded article according to any one of claims 1 to 5, wherein the norbornene-based polymer composition further contains a conductive agent.   The norbornene-based polymer molded article according to any one of claims 1 to 6, wherein the glass transition temperature is 35 ° C or higher and 45 ° C or lower.