JP4627619B2 - Sheet, electrical insulation protector, and electrical insulation method - Google Patents

Description

The present invention relates to a sheet formed from an electrically insulating composition as a raw material.

There are cases where electrical work is carried out with current flowing through the high-voltage wire. Such work is called high-voltage live-line work or high-voltage live-line proximity work, etc., and it is not necessary to make a power outage in order to perform electrical work while supplying power to the user. It is expensive and has been widely used in recent years.
By the way, in order to perform the high-voltage live wire work and the high-voltage live wire proximity work, an operator needs to wear a protective device having an electrical insulating property to prevent an electric shock.

  As protective equipment used for high-pressure live wire work and high-pressure live wire proximity work, molded products using vulcanized rubber such as EPDM rubber, and welding of resin sheets represented by EVA (ethylene-vinyl acetate copolymer resin) Processed products are known.

  Here, the former electric insulation clothing using vulcanized rubber has a problem that it is heavy and inferior in comfort and operability although it has high electric insulation and is durable and long-lasting. In addition, it is difficult to make various sizes and shapes of electrical insulation clothing using vulcanized rubber because it is necessary to fill the mold with unvulcanized rubber and vulcanize it. Furthermore, since vulcanized rubber is difficult to melt by heat, it is difficult to recycle compared to resin and the like.

On the other hand, the electrical insulation clothing using a resin sheet forms a weldable sheet, then cuts it into parts of a predetermined shape in the same way as the clothing is molded, and applies high frequency welder welding to connect the parts together. Made by joining. As described above, since the electrical insulation clothing using the resin sheet can be molded by the high frequency welder, there is an advantage that various sizes and designs can be easily made. In addition, the electrical insulation clothing that uses resin sheets joins each part by high-frequency welder welding and does not sew with needles or threads, so there are no holes on the surface of the electrical insulation clothing, and insulation safety is high. .
Furthermore, since the electrical insulation clothing using the resin sheet can be remelted, it can be easily recycled. Therefore, the mainstream of electrical insulation clothing is shifting from those using vulcanized rubber to those using resin sheets.

  For example, Patent Document 1 below discloses an electrical insulation garment using a resin sheet. The invention disclosed in Patent Document 1 is an electrical insulation garment made by sewing by heat sealing using a cloth in which a fiber cloth is coated with a resin.

JP 57-199803 A

  However, an electrical insulation garment using a resin sheet has a problem of low durability due to poor mechanical performance (breaking strength, breaking elongation, etc.). In order to make up for this, a method of reinforcing the resin with a fiber cloth or the like can be considered as in the invention disclosed in Patent Document 1 described above, but there is a problem that the resin reinforced with the fiber cloth or the like is difficult to be recycled. .

In order to compensate for the lack of mechanical performance, it is conceivable to increase the thickness of the resin sheet. However, increasing the thickness of the resin sheet reduces the flexibility of the sheet itself, and the electrical insulation clothing is inferior in elasticity and inferior in comfort. This hinders electrical work.
For this reason, a method has been proposed in which a large number of thin resin sheets are stacked and an electrical insulation garment is formed using the stacked resin sheets. However, when a large number of resin sheets are stacked, a through hole or the like is formed in the resin sheet in the middle. Even if there is a defect, visual confirmation from the outside cannot be performed, and there is a problem that reliability as an electrical insulation suit is lacking.
In addition, electrical insulation clothing using resin sheets has the greatest advantage in that each part can be joined using high-frequency welder welding, but in order to employ resin sheets as materials for electrical insulation clothing, high-frequency welder welding is required. In addition to the basic performance of exhibiting easy and high bonding strength, the performance of high electrical insulation, softness, and high mechanical strength is required. However, these four properties are mutually contradictory properties, and a resin composition that satisfies all of these properties is not known.
That is, a resin composition that is easy to weld with a high frequency and exhibits high bonding strength has a high polarity and low electrical insulation. On the other hand, a resin composition having high electrical insulation generally has a low mechanical strength and is hard, and is not suitable as a material for a person to wear.

  Therefore, the present invention pays attention to the above-mentioned problems of the prior art, and is sufficiently strong even without reinforcement of fibers and the like, flexible, excellent in electrical insulation, and capable of high-frequency welder welding. Development of a resin composition is a technical issue. In addition, the present invention has an object to develop a sheet suitable as a material for an electrical insulation protector and to develop an electrical insulation protector that is comfortable to wear.

And as a result of earnest research to achieve the above-mentioned purpose, at least the first component, the second component, and the softening agent for the second component are contained, and the first component, the second component, and the softening agent are melt-mixed. a sheet made of an electrically insulating composition comprising Te, the first component is a main component of polyurethane-based thermoplastic elastomer, which generates heat melted under high frequency electric field, said second component is a vinyl aromatic The main component is a hydrogenated product of a conjugated diene block copolymer, the degree of exothermic melting under a high frequency electric field is inferior to that of the first component, and the volume resistivity is larger than that of the first component . for viscous, when the viscosity of the second component which is softened by added to a compounding ratio of the softening agent in the electrically insulating composition is higher than the viscosity of the first component, the I began to see that satisfies the four performance. That is, the above-described electrical insulating composition is easy to weld with a high frequency and can exhibit high bonding strength, has high electrical insulation, is soft, and has high mechanical strength (Claim 1).

Moreover, in this invention, since the said 1st component has a polyurethane type thermoplastic elastomer as a main component, it has a softness | flexibility and intensity | strength and heat resistance is high compared with EVA etc. Further, since the second component is mainly composed of a hydrogenated vinyl aromatic / conjugated diene block copolymer, it has excellent electrical insulation and can be easily plasticized with a softening agent.
Moreover, since it is a sheet | seat , it can be cut | judged to a predetermined part shape, and shaping | molding of a desired final product is easy.

Similarly, a sheet comprising an electrically insulating composition comprising at least a first component, a second component, and a softening agent for the second component, and melt-mixing the first component, the second component, and the softening agent. The first component is mainly composed of a polyurethane-based thermoplastic elastomer and heat-melts under a high-frequency electric field, and the second component is a hydrogenated vinyl aromatic / conjugated diene block copolymer. And the degree of heat generation and melting under a high frequency electric field is inferior to that of the first component, the volume resistivity is larger than that of the first component, and the first component and the second component are the first component and the first component. The second mixed with the energy per unit time required to stir a certain amount of the first component alone and the blending ratio in the electrically insulating composition under the temperature conditions when the two components are melt-mixed. Completion When the energy per unit time required for mixing and stirring an amount equal to that of the first component, which is a mixture of the softening agent, is compared with the latter second component and the softening energy Even when the energy is smaller than the energy required for stirring the mixture of the agent, the above four performances are satisfied (Claim 2).

Moreover, in this invention, since the said 1st component has a polyurethane type thermoplastic elastomer as a main component, it has a softness | flexibility and intensity | strength and heat resistance is high compared with EVA etc. Further, since the second component is mainly composed of a hydrogenated vinyl aromatic / conjugated diene block copolymer, it has excellent electrical insulation and can be easily plasticized with a softening agent.
Moreover, since it is a sheet | seat , it can be cut | judged to a predetermined part shape, and shaping | molding of a desired final product is easy.

The sheet further comprises at least a first component, a second component, and a softening agent for the second component, and is made of an electrically insulating composition formed by melting and mixing the first component, the second component, and the softening agent. The first component is mainly composed of a polyurethane-based thermoplastic elastomer and heat-melts under a high frequency electric field, and the second component is mainly a hydrogenated vinyl aromatic / conjugated diene block copolymer. The component is inferior to the first component in terms of heat generation and melting under a high-frequency electric field, the volume resistivity is larger than the first component, the second component is dispersed independently inside, and the first component is The above-mentioned four performances were also satisfied for those existing in the state of filling the gap between the second components (claim 3).

Moreover, in this invention, since the said 1st component has a polyurethane type thermoplastic elastomer as a main component, it has a softness | flexibility and intensity | strength and heat resistance is high compared with EVA etc. Further, since the second component is mainly composed of a hydrogenated vinyl aromatic / conjugated diene block copolymer, it has excellent electrical insulation and can be easily plasticized with a softening agent.
Moreover, since it is a sheet | seat , it can be cut | judged to a predetermined part shape, and shaping | molding of a desired final product is easy.

It is desirable that the second component softened by adding the above-described softening agent so as to have a blending ratio in the electrical insulating composition is softer than the first component at room temperature.

  By making the second component softer than the first component at room temperature, the electrically insulating composition can be made flexible.

The blending ratio of the softener is preferably 10 to 300 parts by weight with respect to 100 parts by weight of the hydrogenated vinyl aromatic / conjugated diene block copolymer as the second component.

  According to this formulation, the second component can be softened while suppressing the separation of the softener.

  In the case of adopting the above blending, it is desirable that 50 to 120 parts by weight of the softening agent is blended with 100 parts by weight of the hydrogenated product of the vinyl aromatic / conjugated diene block copolymer. ).

  According to the above blending, 50 to 120 parts by weight of the softening agent is blended with 100 parts by weight of the hydrogenated product of the vinyl aromatic / conjugated diene block copolymer. The hydrogenated product of the aromatic / conjugated diene block copolymer can be softened.

  Moreover, it is desirable that 10 to 200 parts by weight of the mixture of the second component and the softener is blended with respect to 100 parts by weight of the first component.

  Further, it is desirable that the solid material of the first component has a higher tensile strength at room temperature than the solid material of the second component (claim 8).

  Moreover, you may provide an unevenness | corrugation in the single side | surface or both surfaces of a sheet | seat (Claim 9).

  When unevenness is provided on one or both sides of the sheet in this way, the sheets are less likely to adhere to each other when used in a stacked manner, and even when the stacked sheets are used for clothes, etc., they are easily deformed according to the movement of the user. .

The above-mentioned sheet may have a foamed structure (claim 10).

  According to this configuration, foaming is performed at the time of molding, and since the space is provided inside, the composition can be lightened.

An electrical insulation protector comprising the sheet of the present invention is provided (claim 11).

An electrical insulation method using the sheet of the present invention is provided (claim 12).

By using the above-described sheet as a raw material and joining the parts molded into a predetermined shape by high-frequency welder welding, an electrical insulation protector can be easily manufactured.
Examples of electrical insulating protective equipment include outerwear-like, waistcoat-like, clothes-like clothing with a hood and hat integrated like a jacket, cover-like-like, trouser-like, hat-like A thing which covers all the head, torso, upper limbs and lower limbs like a thing, a diving suit, a glove-like thing, a surface or a mask-like thing etc. can be considered.

ADVANTAGE OF THE INVENTION According to this invention, it can provide the sheet | seat which has electrical insulation and can be used for the protective equipment of protective clothing, protective gloves, etc. In addition, the sheet of the present invention can join parts by high-frequency welder welding and has high insulation performance, so that there is an effect that the degree of freedom in designing an electrical insulation protector can be increased.

Hereinafter, the present invention will be described in detail.
The electrically insulating composition constituting the sheet of the present invention contains a first component, a second component, and a softening agent.
It is desirable that the first component exhibits an appropriate strength (breaking strength, breaking elongation, etc.) when it becomes solid, and in particular, it is desirable that the strength be higher than that of the second component. As a result, the strength of the sheet of the present invention can be increased. The first component is a material that generates a large amount of dielectric loss when solid and can be welded at high frequency.
Here, “high-frequency welder welding” is one of the welding techniques, and a predetermined part is formed by dielectric heating that self-heats (dielectric loss heat generation) of a material (dielectric) placed in a high-frequency strong electric field. It is heated to raise the temperature to near the melting point or higher and weld. The amount of dielectric loss heat generation varies depending on the material, and the degree of melting relative to the amount of heat generated also varies depending on the material. For this reason, there are materials that can easily perform high-frequency welder welding, and materials that are difficult to perform high-frequency welder welding.

Furthermore, the electrically insulating composition constituting the sheet of the present invention is one in which the first component, the second component and the softening agent are melt-mixed at a predetermined temperature, but the second component softened by the softening agent is: Since the viscosity at the time of melt mixing is higher than that of the first component (Claim 1), the second component softened by the softener is dispersed independently, and the first component is softened by the softener. It is expected that the gap exists between the second components or a state close to this. In other words, it is envisaged that the first component is sea-like and the second component softened by the softening agent has a so-called sea-island structure in which it is island-like or close to this.

Similarly, the energy per unit time (working power) required to stir a certain amount of the first component alone under the temperature condition when the first component and the second component are melt-mixed, the second component, and When the energy per unit time required to mix and stir an amount equal to the first component, which is a mixture of softeners, is compared with the latter second component and softener Even in the case where the energy is smaller than the energy required for stirring, the second component softened by the softener is dispersed independently, and the first component fills the gap between the second components softened by the softener. It is expected to be in or close to the state.
The energy required for stirring is per unit time, and can be known by, for example, putting a predetermined amount of sample into a mixing apparatus such as a Banbury mixer and measuring the current value and torque of the motor at that time. It is desirable that the energy per unit time required for stirring the first component and the energy (working rate) required for stirring the second component and the softening agent are smaller by 13% or more than those of the second component.

And what mixed the 2nd component and the softening agent has a desirable thing softer than a 1st component, and this can provide the softness | flexibility of the whole composition, suppressing the fall of the intensity | strength of the whole composition. .
Furthermore, since the volume resistivity of the mixture of the second component and the softening agent is larger than that of the first component, the electrical insulation of the entire composition can be improved. The reason why the electrical insulation is improved by mixing the second component is that when a potential is generated on both sides of the composition, the path through which the current due to the first component flows is hindered by the second component. This is probably because of this.

In the present invention, the second component is relatively difficult to weld with a high frequency welder. However, since the first component present in the “sea state” is excellent in the high frequency welder property, the joint surface is heated and melted as a whole. They are welded together.
Even if the second component alone has a small dielectric loss heat generation and the second component alone cannot perform high-frequency welder welding, the first component surrounding the second component generates heat, so the second component generates heat from the first component. It is heated and melted by conduction.
That is, the second component is difficult to self-heat even when subjected to a high-frequency electric field, but since the second component is a thermoplastic resin, it softens and melts when it receives heat from the surroundings. When an additional note, compositions of the present invention, either the first component is a so-called sea-island structure in which the second component is island in the sea like, since in the state close to this, the second component is hard to self-heating It is in a state of being surrounded by a first component that is easily self-heating. And since the 2nd component which exists in the circumference | surroundings heat | fever-generates, it will estimate | forecast that the 1st component surrounded by this will heat up and will be in the state which can be welded.

Therefore, when the electrically insulating composition in the present invention is exposed to a high frequency electric field, the whole is softened and melted. Therefore, this electrically insulating composition has no uneven heating of the composition, the surface temperature is likely to rise, and high-frequency welder welding is easy to perform.

In the present invention, the first component is mainly composed of a polyurethane-based thermoplastic elastomer, and the second component is mainly composed of a hydrogenated vinyl aromatic / conjugated diene block copolymer.
When other components are used as the first component and the second component, it is essential that the second component has a larger volume resistivity than the first component. Specifically, it is desirable that the second component has a large volume resistivity about 10 to 10 ⁴ times that of the first component. Moreover, the difference between the two recommended more than 100 times.
The volume resistivity of the polyurethane-based thermoplastic elastomer that is the main component of the first component is about 10 ¹² to 10 ¹⁴ Ω · cm, and the vinyl aromatic and conjugated diene block copolymer that is the main component of the second component. In the combined hydrogenated product, it is about 10 ¹⁵ to 10 ¹⁶ Ω · cm.

  The hardness of the second component in a state mixed with the softening agent is lower than that of the first component. That is, the second component in a state mixed with the softening agent is softer than the first component.

  The polyurethane-based thermoplastic elastomer that is the main component of the first component of the present invention is classified according to the linear polyol to be used, and can be any of polyester-based (caprolactone-based, adipate-based), polycarbonate-based, and polyether-based. Can be used.

The melt flow rate (230 ° C., 2.16 kg weighted value, hereinafter abbreviated as MFR) of the polyurethane-based thermoplastic elastomer which is the main component of the first component of the present invention is preferably 0.5 to 100 g / 10 min. More preferably, it is 5-50 g / 10min. If the MFR is less than 0.5 g / 10 min, the fluidity is poor and the moldability is poor, and the polyurethane thermoplastic elastomer as the first component is unlikely to be “sea”, resulting in poor high-frequency welder welding performance as a whole. It becomes.
On the other hand, if the MFR exceeds 100 g / 10 min, the mechanical properties tend to be inferior, which is not preferable.

The hydrogenated vinyl aromatic / conjugated diene block copolymer as the main component of the second component has two or more polymer blocks A composed of vinyl aromatic compounds in the molecule, and is conjugated. A hydrogenated block copolymer obtained by hydrogenating a block copolymer having at least one polymer block B composed of a diene compound. For example, (AB) _n -A (n is an integer of 1 to 10) Vinyl aromatic compound / conjugated diene compound block copolymer having a structure such as (A-B) _m -X (X represents a coupling agent residue, m represents an integer of 2 to 15) And a hydrogenated block copolymer obtained by hydrogenation.

  In the hydrogenated block copolymer, the vinyl aromatic compound content is preferably in the range of 5 to 50% from the viewpoint of flexibility, moldability, and mechanical strength of the sheet made of the vinyl aromatic thermoplastic elastomer to be obtained. If this ratio is less than 5%, the mechanical properties of the sheet are insufficient. Conversely, if it exceeds 50%, the viscosity at the time of molding may be remarkably increased.

  Examples of the vinyl aromatic compound constituting the hydrogenated vinyl aromatic / conjugated diene block copolymer include styrene, α-methylstyrene, o-, m- or p-methylstyrene, and 1,3-dimethylstyrene. Vinyl naphthalene, vinyl anthracene and the like. Among these, styrenes such as styrene and α-styrene are preferable. A vinyl aromatic compound may be used independently and may use 2 or more types together. Further, as the compound constituting the hydrogenated block copolymer, for example, butadiene, isoprene, or a mixture of butadiene and isoprene is preferable, and the form in the case of using a mixture of isoprene and butadiene may be random, block, or tapered. Good. It is also possible to introduce 1,2 and 3,4 bonds, commonly referred to as vinyl bonds.

As a method for producing the block copolymer, for example, the following known anionic polymerization method can be employed. That is, a block copolymer is formed by sequentially polymerizing with a vinyl aromatic compound and a conjugated diene compound in an inert organic solvent using an alkyl lithium compound or the like as an initiator. Then, the obtained block copolymer can be hydrogenated in the presence of a hydrogenation catalyst in an inert organic solvent according to a known method to synthesize a hydrogenated block copolymer. At this time, from the viewpoint of heat resistance and weather resistance, it is preferable to hydrogenate 70% or more of unsaturated double bonds derived from the conjugated diene compound in the block copolymer before hydrogenation. The ratio of unsaturated double bonds in the polymer block in can be confirmed by iodine value measurement, infrared spectrophotometer, nuclear magnetic resonance apparatus or the like.

  Further, the hydrogenated product of the vinyl aromatic / conjugated diene block copolymer as the main component of the second component is a carboxyl group, a hydroxyl group, an acid in the molecular chain or at the molecular end unless the purpose of the present invention is impaired. You may contain functional groups, such as an anhydride, an amino group, and an epoxy group. Typical examples of the method for containing a functional group include a method in which maleic anhydride is subjected to a radical reaction in an extruder, and a method in which ethylene oxide is added to active terminal lithium after polymerization.

  The hydrogenated vinyl aromatic / conjugated diene block copolymer as the main component of the second component preferably has a number average molecular weight of 150,000 or more and less than 300,000. That is, when the number average molecular weight is 150,000 or less, it is considered that the viscosity at the time of kneading is excessively reduced, and the second component side is unlikely to become “sea”, and the bonding strength when the high frequency welder is welded is weak . On the other hand, when the number average molecular weight is 300,000 or more, the viscosity of the entire composition is excessively increased and the processability is inferior.

In addition, a softening agent is added to the electrically insulating composition in the present invention. As the softening agent, known ones used as rubber softening agents can be used, and any of paraffinic process oil, naphthenic process oil, aromatic process oil and the like may be used. It is also possible to use synthetic oils. Moreover, the softening agent for rubber | gum may be mix | blended independently and may use 2 or more types together.
And a softener is mixed with the main component of the 2nd component at the time of a mixing | blending or mixing, and mainly softens a 2nd component.
The blending amount of the softening agent is desirably in the range of 10 to 300 parts by weight with respect to 100 parts by weight of the hydrogenated vinyl aromatic / conjugated diene block copolymer which is the main component of the second component, and particularly 50 It is desirable to be in the range of ~ 120 parts by weight. That is, if the blending amount of the softening agent is small, the flexibility is insufficient, and if it is too large, the desired mechanical strength is difficult to obtain.

  Moreover, in order to adjust or stabilize the dispersion | distribution state of a 1st component and a 2nd component, the well-known compatibilizing agent can be mix | blended with the electrically insulating composition in this invention. In this case, the compatibilizer is desirably blended in an amount of 5 to 40 parts by weight with respect to 100 parts by weight of the first component.

  Moreover, a filler can be added to the electrically insulating composition according to the present invention as necessary within a range not impairing the gist of the present invention. Examples of the filler include calcium carbonate, talc, titanium oxide, silica, clay, barium sulfate, magnesium carbonate, and glass fiber.

  Furthermore, pigments, lubricants, stabilizers, flame retardants and the like can be added to the electrically insulating composition according to the present invention as necessary within a range not impairing the gist of the present invention.

A conventionally known molding method can be used for molding the molded article with the electrically insulating composition in the present invention. Furthermore, as a method for producing the sheet of the present invention , a conventionally known method can be used without any particular limitation. When mixing the above components, knead in a heated and melted state using a kneader such as a single screw extruder, twin screw extruder, super mixer, Banbury mixer, Brabender, open roll, kneader, etc., if necessary. By doing so, dispersion can be improved.

  As a specific molding method, for example, it can be processed into a molded body in the same manner as an ordinary resin using an extrusion molding machine or an injection molding machine. In addition, the sheet is particularly easily obtained by calendar molding, T-die extrusion, or the like. Furthermore, by using the electrically insulating composition in the present invention, it is easy to increase the dimensional accuracy as compared with the case of using a vulcanized rubber that requires a vulcanization step. Furthermore, in calender molding, molding with a highly viscous composition is easier than extrusion molding. In addition, when a composite material is extruded, a difference in the blending ratio tends to occur between the surface and the inside of the molded product due to the flow characteristics of the material, but such a difference is unlikely to occur in calendar molding.

In the sheet of the present invention, unevenness may be provided on one side or both sides of the sheet. As a method for embossing the sheet, a conventionally known method can be used without any particular limitation. For example, an ordinary extrusion molding machine or a method of molding the mold of an injection molding machine with irregularities can be employed. Furthermore, when processing into a sheet by calender molding or T-die molding, a method of forming on a support with unevenness and then peeling the support, or a method of forming unevenness with an embossing roll after heating the sheet, etc. Any surface irregularities can be easily obtained.
When two sheets with a smooth surface are used in an overlapping manner, there is an adverse effect of hindering the relative movement between the sheets, but the sheet with unevenness is a relative movement even when two sheets are stacked. Is hard to be disturbed.

  Further, a foaming agent may be added and foamed during molding to form a bubble space inside. In such a case, if the sheet is the same material and the same thickness, the sheet can be lightened, and if the same material and the same weight, the thickness can be increased.

And the sheet | seat of this invention can be cut | judged to predetermined shape (parts), and these can be mutually joined by a high frequency welder welding machine, and the protective clothing which has electrical insulation can be produced. At this time, it is also possible to fabricate one layer or two layers of the same sheet without stacking the sheets in a multilayer shape.
When two layers of sheets are used in an overlapping manner, it is desirable to use two layers that have different colors. That is, when a sheet with two layers of different colors is used, the other side can be seen through when one side breaks and a through hole is formed. Therefore, the breakage of the sheet can be detected at an early stage.

  In addition, the electrically insulating composition in this invention can also be shape | molded and used in three dimensions, such as shapes different from a sheet form, for example.

  Moreover, a microscope etc. are used for confirmation of the dispersion state of the 1st component and 2nd component of the electrically insulating composition in this invention. As a specific method, the cross-section is dissolved with a solvent that dissolves only one resin, and the first component and the second component are observed and confirmed with a microscope such as an optical microscope or an electron microscope. There is a method of confirming the cross section with a microscope as a thin film.

The present invention will be specifically described below with reference to examples which are sheet-like molded products, but the present invention is not limited to these examples.
For Examples 1 to 3 and Comparative Examples 1 to 3, a polyurethane-based thermoplastic elastomer is used as the first component. For Examples 1 to 3 and Comparative Examples 2 and 3, the main component of the second component is used. As a component, a hydrogenated block copolymer which is a hydrogenated product of a vinyl aromatic / conjugated diene block copolymer is used. Paraffin oil is used as the softening agent.

Example 1
The composition of the electrically insulating composition of Example 1 is as follows.
That is, a polyurethane-based thermoplastic elastomer (manufactured by SK Chemicals, trade name: SKYTHANE CS185A) was used as the first component.
As the second component, a hydrogenated block copolymer (manufactured by Kuraray Co., Ltd., trade name: Septon 4055: number average molecular weight 200,000, styrene content 30%, hydrogenation rate 95% or more) was used.
In addition, paraffin oil (manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana Process Oil PW-380) was used as a softening agent.
100 parts by weight of the first component, 40 parts by weight of the second component, and 20 parts by weight of the softening agent were blended, and were melt-kneaded at 200 ° C. and pelletized using a twin screw extruder. The obtained pellets were kneaded for 5 minutes with a Banbury mixer, and then kneaded for 6 minutes with a two-roll warm-up roll.
Then, using an inverted L-shaped four-roll calender, a polyester taffeta (yarn density was 210 yarns / inch) was used as a support, and the composition was stuck thereon so as to have a thickness of 0.5 mm. And the stuck composition was peeled from the polyester taffeta to obtain a sheet-like molded product.

  The polyester taffeta as a support is a cloth which is a woven fabric made of polyester fibers, and this cloth has irregularities formed by the woven fabric. Accordingly, the unevenness is transferred to the sheet-like molded product, which is a molded product, and an uneven shape is formed on the surface thereof. The polyester taffeta used in the following examples and comparative examples is the same, and similar irregularities are formed.

In addition, as an experiment separate from the mixing of the electrical insulating composition and the molding of the sheet-like molded product, the viscosity of the first component used in the electrical insulating composition of Example 1 and the above-mentioned blending ratio in the second component The viscosities of the compositions with the added softeners were compared.
Specifically, using LABO PLASTOMILL (MODEL 30C150) manufactured by Toyo Seiki Seisakusho Co., Ltd., kneading at 200 ° C., measuring the torque in a stable state after 5 minutes from the start of kneading, Compared. This torque measurement is to measure the energy (working rate) per unit time required to stir a certain amount of components, and the viscosity under temperature conditions during kneading can be confirmed.

As a result, the torque when kneading the first component at 200 ° C. was 6.893 N · m (0.7034 kgf · m). The torque when kneading the composition in which the above-mentioned amount of the softening agent was added to the second component at 200 ° C. was 21.59 N · m (2.203 kgf · m). As is clear from this result, the torque condition during kneading at 200 ° C. is lower in the first component than in the second component (about 68% smaller), and the temperature conditions when the first component and the second component are melt-mixed Below, a unit required to mix and stir an amount of energy per unit time required to stir a certain amount of the first component alone, and a mixture of the second component and softener, which is equal to the first component When comparing the energy per time, the energy per unit time required for stirring the former first component may be smaller than the energy per unit time required for stirring the second second component and softener. found.
Therefore, the viscosity of the first component at the time of melt mixing (200 ° C.) is smaller than that of the second component.

(Example 2)
The composition of the electrically insulating composition of Example 2 is as follows.
That is, a polyurethane-based thermoplastic elastomer (manufactured by SK Chemicals, trade name: SKYTHANE CR180A) was used as the first component.
As the second component, a hydrogenated block copolymer (manufactured by Kuraray Co., Ltd., trade name: Septon 8006: number average molecular weight 200,000, styrene content 33%, hydrogenation rate 95% or more) was used.
In addition, paraffin oil (manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana Process Oil PW-380) was used as a softening agent.

  100 parts by weight of the first component, 50 parts by weight of the second component, and 50 parts by weight of the second component softener are blended and melted at 200 ° C. using a twin-screw extruder. Kneaded and pelletized. The obtained pellets were kneaded for 5 minutes with a Banbury mixer, and then kneaded for 6 minutes with a two-roll warm-up roll. Then, as in the previous example, a polyester taffeta (yarn density 210 yarns / inch) was used as a support using an inverted L-shaped four-roll calender so that the composition had a thickness of 0.5 mm. Affixed. And the stuck composition was peeled from the polyester taffeta to obtain a sheet-like molded product.

In addition, as an experiment different from the previous molding of the electrically insulating composition and the sheet-like molded product, the viscosity of the first component used in the electrically insulating composition of Example 2 in the same manner as in Example 1, The viscosities of compositions in which the above-mentioned blending ratio of the softener was added to the second component were compared.
As a result, the torque when stirring the first component under the temperature condition when the first component and the second component are melt-mixed is 6.647 N · m (0.6783 kgf · m), and the second component The torque when stirring the mixture of the softener and the softening agent was 15.92 N · m (1.624 kgf · m). That is, the energy per unit time required for stirring the first component and the energy per unit time required for stirring the second component and the softener are 58% smaller than those obtained by mixing the second component and the softener.
Therefore, the torque at the time of kneading at 200 ° C. is smaller for the first component than the mixture of the second component and the softening agent, and the viscosity of the first component at 200 ° C. is the mixture of the second component and the softening agent. Smaller than the one.

(Example 3)
The composition of the electrically insulating composition of Example 3 is as follows.
That is, as the first component, a polyurethane-based thermoplastic elastomer (manufactured by Kuraray Co., Ltd., trade name: Clamiron 8165) was used.
As the second component, a hydrogenated block copolymer (manufactured by Kuraray Co., Ltd., trade name: Septon 8006: number average molecular weight 200,000, styrene content 33%, hydrogenation rate 95% or more) was used.
As the softening agent, paraffin oil (manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana Process Oil PW-380) was used.
100 parts by weight of the first component, 50 parts by weight of the second component, and 75 parts by weight of the softening agent were blended, and the mixture was melt-kneaded at 200 ° C. and pelletized using a twin screw extruder. Then, 5 parts by weight of azodicarboxylic amide (foaming agent) (trade name; Uniform AZ-H Ultra # 1100) manufactured by Otsuka Chemical Co., Ltd. was added as a foaming agent to 100 parts by weight of the obtained pellets. The mixture was kneaded for 5 minutes, and then kneaded for 6 minutes by a two-roll warm-up roll. Then, as in the previous example, a polyester taffeta (yarn density 210 yarns / inch) was used as a support using an inverted L-shaped four-roll calender so that the composition had a thickness of 0.5 mm. Affixed. Thereafter, the sheet was heated using a foaming furnace to foam the sheet, and the thickness of the sheet was changed from 0.5 mm to 1.0 mm. And the stuck composition was peeled from the polyester taffeta to obtain an electrically insulating foamed sheet-like molded product.

In addition, as an experiment different from the previous molding of the electrically insulating composition and the sheet-like molded product, the viscosity of the first component used in the electrically insulating composition of Example 2 in the same manner as in Example 1, The viscosities of the compositions in which the above-mentioned blending ratio of the softener was added to the second component were compared.
As a result, the torque when stirring the first component under the temperature condition when the first component and the second component are melt-mixed is 8.674 N · m (0.8851 kgf · m), and the second component It was 9.976 N · m (1.018 kgf · m) for the mixture of the saponin and the softener. That is, the energy per unit time required for stirring the first component and that required for stirring the second component and the softening agent are 13% smaller than those of the second component.
Therefore, the torque at the time of kneading at 200 ° C. is smaller for the first component than the mixture of the second component and the softening agent, and the viscosity of the first component at 200 ° C. is the mixture of the second component and the softening agent. Smaller than the one.

(Comparative Example 1)
The composition of the electrically insulating composition of Comparative Example 1 is as follows.
That is, the same polyurethane-based thermoplastic elastomer (manufactured by SK Chemicals, trade name: SKYTHANE CS185A) as the first component of Example 1 was used. There is no equivalent to the second component.
The above components were kneaded for 5 minutes with a Banbury mixer, and then kneaded for 6 minutes with a two-roll warm-up roll. In the same manner as in the previous example, a polyester taffeta (yarn density 210 pieces / inch) was used as a support using an inverted L-shaped four-roll calender, and the composition was pasted thereon so that the composition had a thickness of 0.5 mm. I wore it. And the stuck composition was peeled from the polyester taffeta to obtain a sheet-like molded product.

(Comparative Example 2)
The composition of the electrically insulating composition of Comparative Example 2 is as follows.
That is, a polyurethane-based thermoplastic elastomer (manufactured by SK Chemicals, trade name: SKYTHANE CS185A) was used as the first component.
As the second component, a hydrogenated block copolymer (manufactured by Kuraray Co., Ltd., trade name: Septon 8006: number average molecular weight 200,000, styrene content 33%, hydrogenation rate 95% or more) was used.
As the softening agent, paraffin oil (manufactured by Idemitsu Kosan Co., Ltd., trade name: Diana Process Oil PW-380) was used.
100 parts by weight of the first component, 20 parts by weight of the main component of the second component, and 80 parts by weight of the softening agent of the second component are blended at 200 ° C. using a twin screw extruder. It was melt-kneaded and pelletized. The obtained pellets were kneaded for 5 minutes with a Banbury mixer, and then kneaded for 6 minutes with a two-roll warm-up roll. In the same manner as in the previous example, a polyester taffeta (yarn density 210 pieces / inch) was used as a support using an inverted L-shaped four-roll calender, and the composition was pasted thereon so that the composition had a thickness of 0.5 mm. I wore it. And the stuck composition was peeled from the polyester taffeta to obtain a sheet-like molded product.

Moreover, the viscosity of the 1st component used for the comparative example 2 was compared with the viscosity of the 2nd component and the softening agent by the method similar to above-described Example 1.
As a result, the torque when stirring the first component under the temperature condition when the first component and the second component are melt-mixed is 6.893 N · m (0.7034 kgf · m), and the second component It was 3.569 N · m (0.3642 kgf · m) for the mixture of the saponin and the softener. That is, the energy per unit time required for stirring the first component is larger than the energy per unit time required for stirring the second component and the softener. The magnitude relationship between the torque required to stir the first component (energy per unit time) and the torque required to stir the second component and the softener in Comparative Example 2 is opposite to that in Examples 1-3. That is, the torque at the time of kneading at 200 ° C. is larger for the first component than the mixture of the second component and the softening agent, and the viscosity of the first component at 200 ° C. is the mixture of the second component and the softening agent. Bigger than the one.

(Comparative Example 3)
The composition of the electrically insulating composition of Comparative Example 3 is as follows.
As the first component, a polyurethane-based thermoplastic elastomer (manufactured by SK Chemicals, trade name: SKYTHANE CS185A) was used.
As the second component, a hydrogenated block copolymer (manufactured by Kuraray Co., Ltd., trade name: Septon 4055: number average molecular weight 200,000, styrene content 30%, hydrogenation rate 95% or more) was used as the main component. .
100 parts by weight of the first component and 40 parts by weight of the main component of the second component were blended, and melt kneaded at 200 ° C. and pelletized using a twin screw extruder. The obtained pellets were kneaded for 5 minutes with a Banbury mixer, and then kneaded for 6 minutes with a two-roll warm-up roll. And the 0.5 mm sheet-like molding was obtained by the method similar to the previous.

Moreover, the viscosity of the 1st component used for the comparative example 3 was compared with the viscosity of the 2nd component and the softening agent by the method similar to above-described Example 1.
As a result, the torque when stirring the first component at 200 ° C. under the temperature condition when the first component and the second component are melt mixed is 6.893 N · m (0.7034 kgf · m), The mixture of the second component and the softening agent was 34.44 N · m (3.514 kgf · m). That is, the energy required for stirring the first component is smaller than the energy required for stirring the second component and the softener.
Therefore, the torque at the time of kneading at 200 ° C. is smaller for the first component than the mixture of the second component and the softening agent, and the viscosity of the first component at 200 ° C. is the mixture of the second component and the softening agent. Smaller than the one.

  Table 1 shows the torque and blending ratio at the time of kneading according to the blending of Examples 1 to 3 and Comparative Examples 1 to 3 (mixture of the first component, the second component and the softening agent).

  In Examples 1 to 3 and Comparative Examples 1 to 3, the first component is a polyurethane-based thermoplastic elastomer, and the second component is a vinyl aromatic / conjugated diene block copolymer. The resistance is greater than the first component. Moreover, the 2nd component (Examples 1-3 and Comparative Examples 1-3) softened with the softener is softer than the 1st component, and the hardness of what mixed the 2nd component and the softener is the 1st component. Smaller than. Therefore, it is considered that the tensile strength obtained by mixing the second component and the softening agent is smaller than that of the first component.

Moreover, the internal structure of the electrical insulating compositions of Examples 1 to 3 and Comparative Examples 2 and 3 was confirmed with a microscope. In Examples 1 to 3 and Comparative Examples 2 and 3, the sea-island state could not be confirmed.
Therefore, the inner structure was confirmed by molding the first component and the second component to be used in the same manner and blending while changing the dispersion state. As a result, all of these were so-called sea-island structures where one was dispersed independently inside and the other was in a state of filling the gap between the second components. Therefore, in Examples 1 to 3 and Comparative Examples 2 and 3, since the island size is very small (estimated 10 μm or less), it cannot be confirmed, and it seems to be in a sea-island state.

  Specifically, for the components corresponding to Examples 1 to 3 and Comparative Example 3, the first component (polyurethane-based thermoplastic elastomer) is in a sea state where it fills the gap between the second components, and the second component It was a sea-island structure in which islands (hydrogenated block copolymer) were dispersed independently. Moreover, about what corresponds to the comparative example 2, it becomes an island shape in which the first component (polyurethane thermoplastic elastomer) is dispersed independently, and the second component (hydrogenated block copolymer) has a gap between the first components. It was a sea-island structure that was in a state of being buried.

  Therefore, it is considered that a component having a lower viscosity and a lower viscosity at 200 ° C., which is the molding temperature, becomes a sea, and a component having a higher viscosity and a higher viscosity at 200 ° C. becomes an island. It is done.

  With respect to Examples 1 to 3 and Comparative Examples 1 to 3 described above, voltage resistance, peel strength (high frequency welder weldability), tensile strength, hardness, and texture were confirmed.

  The withstand voltage test method was carried out in accordance with the withstand voltage test method for insulation protective equipment and armor prescribed in JIS T8010. The condition was that two samples of the above 0.5 mm thickness were overlapped, and a voltage of 20 kV was applied between both sides for 1 minute to confirm whether or not dielectric breakdown occurred. And when it did not break down, it was set as “◯”, and when it was broken down, “x”.

The test method of peel strength (high frequency welder weldability) is as follows. First, using a Yamamoto Vinita Co., Ltd. type VW-3500A high frequency welder welding machine, welding was performed under conditions of an oscillation frequency of 40.46 Hz, an output of 3.5 W, a welding time of 5 seconds, and a cooling time of 5 seconds. The peel strength was confirmed. The peel strength was confirmed by measuring the strength using a tensile tester (Autograph AG-5kNE type) manufactured by Shimadzu Corporation under a pulling speed of 200 mm / min. The peel strength of 70 N / 3 cm or more was determined to be good for high frequency welder.

  The test method for tensile strength was performed by the method defined in JISK-6251. Specifically, using a tensile tester (Autograph AG-5kNE type) manufactured by Shimadzu Corporation under the condition of a pulling speed of 500 mm / min, the shape of the test piece was No. 3 dumbbell.

  The hardness test method was a durometer type A defined in JISK-6253. A hardness of less than 70 was judged good.

  The texture test method is to cut each sheet into clothes parts, join each part using a high-frequency welder welding machine, produce electrical insulation clothes, and wear comfortably to 40 subjects. It was done by the method of judging whether or not. And when it was judged that 70% or more of subjects were good, it was set as "(circle)", and when that was not right, it was set as "*".

  Table 2 shows the results of confirming the above items for Examples 1 to 3 and Comparative Examples 1 to 3 described above. Moreover, the column of comprehensive evaluation was provided, and comprehensive evaluation was set to "(circle)" when favorable about all the items, and the comprehensive evaluation was set to "x" otherwise.

As is clear from Table 2, Examples 1 to 3 can be used as an electrically insulating composition without causing dielectric breakdown at 20 kV for 1 minute. Examples 1 to 3 have good weldability by high-frequency welder welding, a peel strength of 70 N / 3 cm or higher, and a tensile strength of 14 MPa or higher. It is hard to be damaged. Furthermore, in Examples 1 to 3, the hardness value was small, the hardness was 65 or less, the texture was good, and all items were good.
In Comparative Example 1, dielectric breakdown occurs at 20 kV for 1 minute, which is inferior in electrical insulation as compared with the example of the present invention. For this reason, it cannot be used as an electrically insulating composition. This is considered to be because the electrical insulation is inferior to those of Examples 1 to 3 because the volume resistivity does not have the second component larger than the first component.
In Comparative Example 2, the peel strength was low at less than 70 N / 3 cm due to poor weldability by high-frequency welder welding, and the tensile strength was low at less than 14 MPa. Therefore, it is easy to break when parts are joined by a high frequency welder to form a protector. In Comparative Example 2, the second component (hydrogenated block copolymer) having a low viscosity at 200 ° C. is the sea, and the first component (polyurethane-based thermoplastic elastomer) is an island-island structure. It is thought that the strength has decreased.
Furthermore, in Comparative Examples 1 and 3, the hardness value is large. Specifically, the hardness is 70 or more, and therefore the texture is poor. This is considered to be because the mixture of the second component and the softening agent is hard, so that the whole becomes hard, and as a result, the sheet becomes difficult to bend.

  Furthermore, the compounding ratio of the first component, the second component, and the softening agent in Example 1 described above was changed, voltage resistance, peel strength, tensile strength, hardness, texture were confirmed, and comprehensive evaluation was performed. . Specifically, the ratio of the second component and the softening agent is the same as in Example 1 described above, and the second component softened with the softening agent is 0, 5, 10, It was set to 30, 60, 100, 150, 200, 250 and 300 parts by weight. The results are shown in Table 3.

  As is apparent from Table 3, all the physical properties are good in the range of 10 to 200 parts by weight of the softened second component with respect to 100 parts by weight of the first component. In particular, the voltage resistance and texture were poor when the softened second component was 0 and 5 parts by weight, and the peel strength and tensile strength were low when the softened second component was 250 and 300 parts by weight.

  In addition, the ratio of the first component of Example 1 and the second component softened with the softening agent is left as it is, and the blending ratio of the hydrogenated block copolymer that is the second component and the softening agent is changed, Voltage resistance, peel strength, tensile strength, hardness, and texture were confirmed and comprehensive evaluation was performed. Specifically, the amount of the softening agent was 0, 5, 10, 30, 60, 100, 150, 200, 250, 300, and 350 parts by weight with respect to 100 parts by weight of the second component. The results are shown in Table 4.

  As apparent from Table 4, all the physical properties are good when the amount of the softening agent is 10 to 300 parts by weight with respect to 100 parts by weight of the second component. In particular, when the softening agent was 0 and 5 parts by weight, the texture was poor, and when the softening agent was 350 parts by weight, the peel strength and tensile strength were low.

  In addition, in order to test the preferred number average molecular weight of the hydrogenated vinyl aromatic / conjugated diene block copolymer recommended as the second component, various vinyl aromatic / conjugated diene block copolymers were blended to obtain a number average. Samples having different molecular weights were prepared, and performance tests were conducted in place of the second component of the first example. As a result, when the number average molecular weight of the hydrogenated vinyl aromatic / conjugated diene block copolymer is less than 150,000, the viscosity at the time of kneading is excessively reduced, and the bonding strength is weak when high frequency welder welding is performed. I understood. On the other hand, when the number average molecular weight is 300,000 or more, it was found that the hardness of the entire composition is excessively increased and the processability is inferior.

  INDUSTRIAL APPLICABILITY According to the present invention, it can be used for protective clothing, protective gloves, and the like that require electrical insulation.

Claims (12)

A sheet comprising an electrically insulating composition comprising at least a first component, a second component, and a softening agent for the second component, and melt-mixing the first component, the second component, and the softening agent;
The first component is mainly composed of a polyurethane-based thermoplastic elastomer, and heat-melts under a high-frequency electric field,
The second component is mainly composed of a hydrogenated vinyl aromatic / conjugated diene block copolymer, has a lower degree of heat generation and melting under a high-frequency electric field than the first component, and has a volume resistivity of the first component. Larger than the ingredients,
The viscosity during melt mixing, the sheet characterized by viscosity of the second component which is softened by added to a compounding ratio of the softening agent in the electrically insulating composition is higher than the viscosity of the first component . A sheet comprising an electrically insulating composition comprising at least a first component, a second component, and a softening agent for the second component, and melt-mixing the first component, the second component, and the softening agent;
The first component is mainly composed of a polyurethane-based thermoplastic elastomer, and heat-melts under a high-frequency electric field,
The second component is mainly composed of a hydrogenated vinyl aromatic / conjugated diene block copolymer, and has a lower volume resistivity than the first component in terms of heat generation and melting under a high frequency electric field. Bigger than
The first component and the second component include energy per unit time required to stir a certain amount of the first component alone under a temperature condition when the first component and the second component are melt-mixed. When the energy per unit time required to mix and stir an amount equal to the first component, which is a mixture of the second component and the softener mixed at the blending ratio in the electrical insulating composition, is compared with the former sheets energy required for agitation of the first component is characterized in that less than the energy required for agitation of a mixture of the latter of the second component and a softening agent. A sheet comprising an electrically insulating composition comprising at least a first component, a second component, and a softening agent for the second component, and melt-mixing the first component, the second component, and the softening agent;
The first component is mainly composed of a polyurethane-based thermoplastic elastomer, and heat-melts under a high-frequency electric field,
The second component is mainly composed of a hydrogenated vinyl aromatic / conjugated diene block copolymer, and has a lower volume resistivity than the first component in terms of heat generation and melting under a high frequency electric field. Bigger than
The sheet is characterized in that the second component is dispersed independently inside, and the first component exists in a state of filling a gap between the second components. The second component softened by adding the softening agent so as to have a blending ratio in the electrically insulating composition is softer than the first component at room temperature. The sheet described in. The blending ratio of the softener is 10 to 300 parts by weight with respect to 100 parts by weight of the hydrogenated vinyl aromatic / conjugated diene block copolymer as the second component. The sheet | seat in any one of. The sheet according to any one of claims 1 to 5, wherein 50 to 120 parts by weight of a softening agent is blended with 100 parts by weight of a hydrogenated vinyl aromatic / conjugated diene block copolymer. The sheet according to any one of claims 1 to 6, wherein 10 to 200 parts by weight of a mixture of the second component and the softening agent is blended with respect to 100 parts by weight of the first component. The sheet according to any one of claims 1 to 7, wherein the solid material of the first component has a higher tensile strength at room temperature than the solid material of the second component. The sheet according to any one of claims 1 to 8, wherein unevenness is provided on one side or both sides. The sheet according to any one of claims 1 to 9, wherein the sheet has a foam structure. An electrical insulation protector comprising the sheet according to claim 1. An electrical insulation method using the sheet according to claim 1.