JPH01264829A - Usage of high-molecular orientation elastomer molded body - Google Patents

Abstract

PURPOSE:To use advantageously in a sphere where a material having a function provided with different kinds of physical properties in a temperature sphere of use is required, by a method wherein Tg is set up at around a temperature of ordinary use and a radial change in the physical properties of a high-molecular elastomer molded body around Tg is used. CONSTITUTION:After a high-molecular molded body is molded once into a necessary form for actual use, a deformation of the same is performed at a temperature of at least the Tg and less than a molding temperature and then the deformation is fixed by cooling the same to a lower temperature than the above-mentioned Tg. Then the same is restored to the initial form or a form close to that by heating the same; again to a temperature of at least the Tg. After immersion of a molded sheet 1 comprised of polyurethane elastomer, whose Tg is set up, for example, at 48 deg.C, into warm water of 50 deg.C, the same is made like 1' by deforming the same. An extremely low force is enough to deform the same it is easy to adhere closely to a holding form, when the same is left as it is at a room temperature, the molded sheet 1' is cooled and fixed in a contact form. At the time of attachment and detachment, since the same is restored to the form 1 of the molding time by heating the same at the Tg or more by a hair drier, the attachment and detachment can be performed easily and the molded sheet 1 becomes usable repeatedly.

Description

Detailed Description of the Invention Field of Application of Industry 1] The present invention relates to a method of using a polymer elastomer molded article, and more specifically, to a method of using a polymer elastomer molded article whose glass transition point is set approximately at room temperature. It relates to a method of use that takes advantage of rapid changes in physical properties around the glass transition point.

[Prior Art] As is well known, polymer elastomers have a glass transition temperature (hereinafter referred to as
Tg) exists.

This polymer elastomer normally has a temperature of 7.
In order to avoid physical property changes around 8, we set the Tg at an extremely low temperature of around -40°C, and made use of the low elastic modulus properties of ordinary natural rubber and synthetic rubber even at low temperatures.
It can be used for power transmission belts, tires, etc.
By setting the Tg at an extremely high temperature of 0 to 110°C, and making use of its properties such as high elastic modulus and abrasion resistance even at high temperatures, we have created artificial wood,
It is used for tableware etc.

[Problems to be Solved by the Invention] By the way, the Tg and physical properties of a polymer elastomer, for example, in the case of a urethane elastomer, are determined by the type of incyanate, the type of polyol, the type of chain extender, the blending ratio,
It is known that it can be set freely by considering annealing and the like.

Therefore, an object of the present invention is to propose a method of using a polymer elastomer that utilizes the change in physical properties at around 78, which has not been attempted in the past.

I゛Means for Solving the Problems] The present invention utilizes the fact that a polymer elastomer exhibits a physical property of a low elastic modulus at a temperature below its molding temperature and at a temperature of 78 or higher. It relates to a method of use in which the polymer elastomer is deformed by an external force, and then the deformation is fixed by cooling the polymer elastomer to a temperature lower than Tg, thereby utilizing the physical property of high elastic modulus.

That is, the present invention deforms a polymer elastomer molded article at a temperature below the above-mentioned Tg - below the molding temperature, then cools it to a temperature lower than Tg to fix the deformation, and when used, the elastomer molded article is heated to Tg. This method of using a polymer elastomer molded article is characterized by heating it below the molding temperature to restore it to its original shape.

[Function] In the present invention, after the polymer elastomer molded article is once molded into the shape required for actual use, it is deformed at a temperature higher than the Tg of the polymer elastomer and lower than the molding temperature. The deformation is fixed by cooling to a low temperature.

As a result, in the temperature range below Tg, the polymer elastomer can be used by taking advantage of its properties such as high elasticity and wear resistance.

In addition, by heating to a temperature higher than I"J & Tg, the deformation shown in ":" is automatically removed, and the shape can be restored to the original shape or a shape close to it.

Furthermore, in the temperature range above Tg, the low elastic modulus of the elastomer can be utilized.

Therefore, the method of the present invention can be used in various fields in which it is necessary to change the shape of a molded article.

In the method of the present invention, which functions as described above, the polymer elastomer may be any elastomer as long as it has an elasticity of around 7g near the desired set temperature. Elastomers with a large rate change are preferred, typically polyurethane elastomers,
Styrene-butadiene elastomers, nitrile-butadiene elastomers, etc. can be used.

Next, production examples of polyurethane elastomers having various Tg will be explained.

The incyanate component used to produce the polyurethane elastomer is not particularly limited as long as it is normally used in polyurethanes, such as diphenylmethane diisocyanate, 2.4- or 2.6-)lylene diisocyanate, and the like. Alternatively, p-phenyl diisocyanate, inphorone diisocyanate, hexamethylene diisocyanate and phase components or mixtures thereof are used.

In addition, as a polyol component, at least 2
A polyoxyalkylene polyol having at least two hydroxyl groups is used, and is produced by adding alkylene oxide to a polyhydric alcohol such as a diol or triol using an aliphatic amine or an aromatic amine as an initiator. Alternatively, polyester polyols produced by combining acids and alcohols, polytetramethylene glycols, polybutadiene polyols, etc. are used.

Examples of chain extenders and crosslinking agents include glycols such as ethylene glycol, butanediol, and diethylene glycol, amines such as jetanolamine, triethylamine, tolylenediamine, and hexamethyldiamine, and 1゛Dl of trimethylolpropane. Examples include polyisocyanates such as tolylene diisocyanate (tolylene diisocyanate) adduct and triphenylmethane triincyanate.

Further, a catalyst is used to accelerate the reaction if necessary.

As a catalyst, triethylamine, tetramethylpropylene diamine, tetramethylhexamethylene diamine,
There are metal catalysts represented by tertiary amines such as tolylene diamine, and tin-based catalysts such as stannath octoate, stannath oleate, and dibutyltin laurate, and these can be used individually or in combination. be done.

A urethane elastomer is synthesized by a prepolymer method using an isocyanate, a polyol, a chain extender, and, if necessary, a catalyst.

Next, a method for synthesizing a urethane elastomer using a prepolymer method will be explained.

First, diisocyanate and polyol are mixed at a specific blending ratio A.
Synthesize a prepolymer by reacting at a molar ratio of = [NCD] / [01 (]. After the reaction is completed, the desired blending ratio B
= [Chain extender]/[Prepolymer: Add a chain extender so that the molar ratio is 1, then defoam, pour into a mold, and carry out a crosslinking reaction for 11 to 2 days at a temperature of 80°C in a constant temperature dryer. Synthesize urethane elastomer. The synthesis below can be carried out either in a solvent system or a non-solvent system.

Possible factors that affect Tg include 1) type of incyanate, 2) type of polyol, 3) type of chain extender, 4) blending ratio A15) blending ratio B, 6) annealing, etc. By changing the factors 6), it is possible to freely synthesize a urethane elastomer having the desired Tg and physical properties.

[Example] First, the urethane elastomer that can be used in the method of the present invention will be described with reference to an example prepared by the present inventors.

Ill, Example of making urethane elastomer: 2.4 TI) (manufactured by Mitsubishi Kasei Co., Ltd., trade name 1) + 100] as the isocyanate component and P-1000 (manufactured by Sanyo Kasei Co., Ltd., trade name 1) as the polyol. , to the mixture ratio (
NC01011 molar ratio) 3', 06 was reacted without a catalyst, and the prepolymer was combined.

After the reaction was completed, 1.4-butanediol was added as a chain extender at a blending ratio of HIOI to I/NCO (prepolymer) molar ratio of 0.62, and the mixture was stirred under vacuum to react.

Thereafter, it was poured into a mold and cured at 80° C. for one day to obtain a molded article.

l'g of this molded body was -5 to 0°C (Example No. 2-4 in Table 1).

Polyurethane elastomers synthesized in the same manner with different compositions and blending ratios and their Tg are summarized in Tables 1 and 2.

As is clear from Tables 1 and 2, Tg can be freely selected by combining the hard segment (incyanate, chain extender) and soft segment (polyol) of the polyurethane elastomer.

Similarly, Tg can be freely selected in styrene-butadiene elastomer and nitrile-butadiene elastomer by changing the ratio of hard segment (styrene or nitrile) and soft segment (butadiene).

Next, a method for using the polymer elastomer molded article obtained as described in Section 2 will be specifically described.

The temperature at which the polymer elastomer described above is deformed is less than the Tg of the polymer elastomer to the molding temperature. However, if it is less than 7 g, the deformation will give a new shape, which is not preferable.

There are no particular restrictions on how to give the deformation, and the molded body is
It can be placed in an atmosphere of 8 or more (for example, heated air, heated liquid, steam, etc.) and deformed using an appropriate tool or bare hands. .

To fix the deformation, it is only necessary to cool it to a temperature of 7 g or less immediately after the deformation is applied. Creep deformation can also be given with less than 7g.

In order to remove the above deformation and change it to a predetermined shape or physical properties, it is sufficient to heat the molded product to a temperature of 78 or higher and lower than the molding temperature, and this heating automatically removes the deformation and restores the shape. At the same time, the physical properties begin to show those of an elastomer.

[2] Example 1 of Use of Molded Body An example of the method of the present invention will be described using a cast shown in FIG. 1 as a molded body.

First, a molded plate made of a polyurethane elastomer shown in 1-5 of Table 1 with Tg set at 48°C] [Figure 1 (a)
After immersing the molding stage in warm water at 50°C for several minutes,
) and make it look like 1' (heating deformation/cooling fixation stage).

Since only a small amount of deforming force is required, it is easy to form a sealed tube in the holding shape (arm portion 2 in the figure).

After being in close contact with each other, if the molded plate 1' is left to stand at room temperature (approximately 35° C. or less) while maintaining its deformation, the molded plate 1' will be cooled and fixed in the tightly bonded shape.

After fixing, at a temperature of 1 g or less, the longitudinal elastic modulus of the molded plate is sufficiently large compared to the longitudinal elastic modulus of Tg or higher, and has a high
Since it has a rigid structure, it does not deform easily and the chain portion is firmly fixed.

Furthermore, when removing and attaching the cast made of the molded plate, by heating the cast with a hair dryer or the like to a temperature higher than Tg, the molded plate becomes less elastic and recovers to the shape 1 at the time of molding. Therefore, [11th: XJ (c) heating, deformation release stage], the j7 can be easily removed, and the molded plate l can be used repeatedly.

Example 2 1- of Table 1 with Tg set at 68℃, around the normal usage temperature
Using the molded polyurethane elastomer shown in No. 7, a two-crop fixing material having the structure shown in FIGS. 2(a) to (c) was prepared.

FIG. 2(a) shows the shape at the time of molding, and the shape was molded into the shape actually used at °C.

Next, it is heated to a temperature of 7 g or more, transformed into a desired shape 3' convenient for storage and transportation, etc., and cooled and fixed. 1 Figure 2 (13)
].

When it is used, it is heated again to recover the shape used during molding, and is made into a shape 3 that allows the workpiece to be identified, as shown by the two-dot chain line in FIG.

Example 3 Normal use? ! Figure 3 (
Tableware 4 shown in a) and (b) was created.

Figure 3 (a) shows the molded and used shape, which is heated and deformed and then cooled to fix the deformation. Figure 3 (1+
) is the shape 4' when not in use.

When heated again to release the deformation, it returns to the shape 4 in FIG. 3(a).

Such tableware has the advantage of requiring less storage space when not in use.

FIG. 4 shows an example of the temperature (C)-M elastic modulus (E) curve of the polymer elastomer used in the method of the present invention. It shows the relationship between molding and T.

1. Effects of the invention] The method of the present invention does not set Tg at an extremely low temperature or an extremely high temperature as in the conventional method (it is set around the normal use temperature, and the rapid physical properties of the polymer elastomer molded product at around 7g). By utilizing this change, it can be advantageously used in various fields that require materials with functions with different physical properties in the operating temperature range.

[Brief explanation of the drawing]

Figures 1 (a) to (c), Figures 2 (a) to (c), and Figure 3.
Figures (a) to (1) are all diagrams showing embodiments of the method of the present invention. Figures 1 (a) to (c) are casts, with Figure 1 (a) in the forming stage, Figure 1 (b) in the heating deformation/cooling fixation stage, and Figure 1 (c) in the heating deformation release stage. shows. Figures 2 (a) to (c) show the workpiece fixing material, Figure 2 (a) is the special shape formed, Figure 2 (b) is the shape when stored and transported,
FIG. 2(c) shows the shape when in use. FIGS. 3(a) to 3(b) show tableware, with FIG. 3(a) showing the shape when molded or in use, and FIG. 3(b) showing the shape when not in use. Figure 4 shows the temperature-longitudinal elastic modulus (E) curve of the polymer elastomer i-mer in the method of the present invention and the Tg hot water temperature forming temperature T3.
It is a graph showing the relationship between. Figure 2 (C) Figure 3 Temperature

Claims (1)

[Claims] The polymer elastomer molded article is deformed at a temperature above the glass transition point and below the molding temperature, and then cooled to a temperature below the glass transition point of the polymer elastomer to fix the deformation. A method of using a polymer elastomer molded article, which comprises heating it to a temperature above the glass transition point and below the molding temperature to restore it to its original shape.