JP5470161B2 - Molded product and method for producing molded product - Google Patents

Description

  The present invention relates to a molded article and a method for producing the molded article. More specifically, the present invention relates to a molded article in which at least a part of the surface is formed of a polymer composition containing a polymeric antistatic agent, and a polymeric charging. The present invention relates to a method for producing a molded article in which at least a part of the surface is formed by a polymer composition containing an inhibitor.

Conventionally, a polymer composition containing a polymer such as a resin or an elastomer as a main component has been widely used as a forming material for various molded products.
For example, extrusion molded products such as inflation films and foamed sheets, secondary processed products thereof, molded products obtained by injection molding or transfer molding of polymer compositions, and molded products such as fabrics and nonwoven fabrics in which polymer fibers are woven. Widely used as a forming material.

By the way, in general, a molded article formed of a polymer composition has a problem that it is easily charged by static electricity, and dust or the like adheres to the surface of the molded article, which easily causes contamination.
In addition, in a molded product used as a container for electric / electronic parts, when static electricity is charged, the stored static electricity may be discharged to these parts, causing failure.
Such a problem may occur not only in a molded product formed only of a polymer composition but also in a composite molded product of a member made of another forming material such as glass or ceramics and a member made of a polymer composition. For example, it is a problem that may occur if at least a part of the surface of a glass fiber reinforced plastic molded article is formed of a polymer composition.

In general, it is known that such problems due to static electricity can be prevented by lowering the value of the surface resistivity of the portion formed by the polymer composition. For example, the surface resistivity of a general resin film The value of is usually a level exceeding 10 ¹⁵ (Ω / □) order, but by reducing this value to 10 ¹³ (Ω / □) order or less, the occurrence of the above-mentioned problems can be prevented. It is known.

As a method for reducing the surface resistivity, a method of incorporating a component called an antistatic agent in a resin composition for forming a molded product has been adopted. Conventionally, a component such as a surfactant is added to a resin film or Inclusion in a forming material such as a foamed sheet is performed.
Those having a molecular weight of about 1000 or less, such as this surfactant, are also called “low molecular antistatic agents”. Although these low molecular antistatic agents are effective for antistatic, Since the diffusion rate in a typical polymer is large, there is a possibility of causing the problem of so-called “bleed out” by leaching on the surface of a molded product such as a resin film with the passage of time.

In recent years, instead of a low molecular weight antistatic agent, a so-called “polymeric antistatic agent” that is effective in antistatic with a high molecular weight substance having a molecular weight exceeding 1000 and reaching several tens of thousands. Use has been studied (see Patent Document 1 below).
The polymer type antistatic agent according to Patent Document 1 is a copolymer having a polar block containing an ether bond or an ester bond and a nonpolar block made of alkyl or the like, and has a low migration property in the polymer. Therefore, the problem of bleed out can be suppressed by using such a polymer type antistatic agent.
On the other hand, since the polymer antistatic agent is not effective unless it is blended in a relatively large amount, and is much more expensive than a polymer used to form a general molded article, If an attempt is made to prevent the molded product from being charged with a high-molecular type antistatic agent, the material cost increases, and the versatility of the molded product may be reduced.

  In order to prevent such a situation, studies have been widely conducted to effectively act a polymer type antistatic agent in a small amount, but the method has not been established.

JP 2008-274031 A

  An object of the present invention is to prevent charge of a molded product such as a resin film or a foamed sheet while reducing the amount of the polymer antistatic agent used.

The present invention relating to a molded article for solving the above-mentioned problems is a molded article having at least a part of the surface formed of a polymer composition containing a polymer-type antistatic agent, and two or more types of non-molded articles A compatible polymer is contained in the polymer composition so that a matrix phase and a dispersed phase dispersed in the matrix phase are formed on at least the surface, and the matrix type antistatic agent is the matrix. A polymer type antistatic agent showing incompatibility is used for both the phase and the dispersed phase, and the dispersed phase is formed as core-shell particles having the polymer type antistatic agent as an outer shell. The dispersed phase contains the core-shell particles having a length in the plane direction of the surface exceeding 1 μm .

Further, the present invention relating to a method for producing a molded article for solving the above-mentioned problems is a method for producing a molded article in which at least a part of the surface is formed by a polymer composition containing a polymer type antistatic agent. Then, by using the polymer composition containing two or more kinds of incompatible polymers, a matrix phase and a dispersed phase dispersed in the matrix phase are formed on the surface, and the high composition As a molecular antistatic agent, a polymer antistatic agent that is incompatible with both the matrix phase and the dispersed phase is used to form core-shell particles having the polymeric antistatic agent as an outer shell. wherein to form a dispersed phase, it is and length in the plane direction of the surface is characterized in Rukoto to form the core-shell particles of more than 1μm so.

In the present invention, a dispersed phase dispersed in the matrix phase is formed on the surface of the molded article, and a so-called “sea-island structure” is formed.
In the present invention, a core-shell particle having the polymer antistatic agent as an outer shell is obtained by using a polymer antistatic agent that is incompatible with both the matrix phase and the dispersed phase. The dispersed phase is formed so that
Therefore, the entire surface of the dispersed phase can be used as a conductive path, and unlike the case where only the polymer antistatic agent is dispersed, the electrical resistance value on the surface of the molded product can be greatly reduced.
That is, it is possible to achieve antistatic while reducing the amount of the polymer antistatic agent used.

The graph which shows the relationship between content of a polymer type antistatic agent and the value of the surface resistivity of a polyolefin-type resin film. The graph which shows the relationship between content of a polymer type antistatic agent and the value of the surface resistivity of a polyolefin-type resin film. The transmission electron micrograph of the surface part of the polyolefin-type resin film produced in manufacture example 1 of a molded article. The transmission electron micrograph of the surface part of the polyolefin-type resin film produced in manufacture example 4 of a molded article. The transmission electron micrograph of the surface part of the polyolefin resin film produced in manufacture example 7 of a molded article. The transmission electron micrograph of the surface part of the polyolefin-type resin foam sheet produced in the manufacture example 8 of a molded article. The transmission electron micrograph of the surface part of the polystyrene-type resin film produced in manufacture example 10 of a molded article. The transmission electron micrograph of the surface part of the polylactic acid-type resin film produced in manufacture example 13 of a molded article. The transmission electron micrograph of the surface part of the polylactic acid-type resin foam sheet produced in the manufacture example 14 of a molded article. A transmission electron micrograph of the surface part of the polyethylene resin film of Reference Example 5. A transmission electron micrograph of the surface part of the polyethylene resin film of Reference Example 6.

(First embodiment)
A resin film and a manufacturing method thereof will be described as a first embodiment of a molded product and a manufacturing method thereof according to the present invention.
First, the resin composition for forming the resin film will be described.

In the resin film of the present embodiment, using two or more kinds of mutually incompatible resins as a forming material together with a polymer antistatic agent can reduce the amount of the polymer antistatic agent used. It is important for the film to exhibit an excellent antistatic effect.
Thereby, a matrix phase and a dispersed phase can be formed on the surface of the resin film.

Further, in the resin film of the present embodiment, as the polymer type antistatic agent, a polymer type antistatic agent that is incompatible with both the matrix phase and the dispersed phase is used. This is important for exerting an excellent antistatic effect on the resin film while suppressing the amount of the mold antistatic agent used.
In this way, for example, a resin for forming the matrix phase, a resin for forming the dispersed phase that is incompatible with the resin, and the polymer antistatic agent are heated and melted. When extruding into a film with an extruder, the polymer-type antistatic agent is precipitated at the interface between the matrix phase and the dispersed phase to form core-shell particles having the polymer-type antistatic agent as an outer shell. To form the dispersed phase.
Therefore, the surface of the dispersed phase can be used as a conductive path, and a large conductive path can be formed on the surface of the resin film while reducing the amount of the polymer antistatic agent used.

The material for forming the matrix phase and the dispersed phase does not have to be a single resin type, and may be composed of, for example, one or more resins that are compatible with each other.
Usually, the polarities and the like are approximated, so that polymers having a solubility parameter (SP value) value difference of 0.5 to 1.0 or less show compatibility, and if the SP value further departs, they show incompatibility. It is said that it becomes.
Therefore, a matrix phase can be formed by using a plurality of polymers having close SP values, and a dispersed phase can be formed by using a plurality of polymers having SP values greatly separated from these polymers.

The matrix phase and the dispersed phase can be reversed depending on the proportion of the forming material.
For example, a resin having a low polarity, generally a low SP value (hereinafter also referred to as “nonpolar resin component”), and a resin having a higher polarity and a higher SP value than this resin (hereinafter also referred to as “polar resin component”) When forming the matrix phase and the dispersed phase in the resin composition constituting the resin film according to the present embodiment so that the nonpolar resin component is larger than the polar resin component, The nonpolar resin component forms a continuous phase on the surface of the resin film to form a matrix phase, and the polar resin component is dispersed in the form of particles to form a dispersed phase.
On the other hand, when the same nonpolar resin component and the polar resin component are used, but the polar resin component is contained in the resin composition so as to be excessively large relative to the nonpolar resin component, the polar resin The component becomes a continuous phase to form a matrix phase, and the nonpolar resin component forms a dispersed phase.

  The solubility parameter is usually obtained by the Fedors equation.

Examples of relatively low polarity resin species for forming the matrix phase and the dispersed phase include polyolefin resins such as polyethylene resins and polypropylene resins.
These are suitable materials for the molded article according to the present embodiment in that many grades are provided on the market, and it is easy to find a desired characteristic and it is relatively inexpensive.

Examples of the polyolefin resin include polyethylene (PE) resin and polypropylene (PP) resin.
Examples of the polyethylene (PE) resin include high density polyethylene resin, medium density polyethylene resin, linear low density polyethylene resin, (high pressure method) low density polyethylene resin, and the like.

Examples of the polypropylene (PP) resin include a homopolypropylene resin composed only of a propylene component, and a random copolymer and a block copolymer containing an olefin component such as ethylene in addition to the propylene component.
In addition, when employ | adopting a copolymer as PP-type resin, what was made to contain olefins other than propylene in the ratio of 0.5-30 mass% in the copolymer, Especially preferably, 1-10 mass%. It is desirable to use it.
Examples of the olefin component in this case include ethylene or an α-olefin having 4 to 10 carbon atoms.

  Further, in the present embodiment, the resin composition for forming the resin film includes polybutene resin and poly-4-methylpentene in addition to the polyethylene (PE) resin and the polypropylene (PP) resin. -1 resin or the like may be contained as the nonpolar component.

Examples of the resin that is incompatible with the polyolefin resin include polystyrene resins.
The polystyrene resin is not particularly limited, and examples thereof include styrene, α-methyl styrene, vinyl toluene, ethyl styrene, i-propyl styrene, t-butyl styrene, dimethyl styrene, bromostyrene, chlorostyrene, and the like. Examples include homopolymers of styrene monomers or copolymers thereof.
The polystyrene resin is a copolymer of the styrene monomer and a vinyl monomer copolymerizable with the styrene monomer, the main component of which is the styrene monomer. Examples of such vinyl monomers include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and cetyl (meth) acrylate, (meth) In addition to acrylonitrile, dimethyl maleate, dimethyl fumarate, diethyl fumarate, and ethyl fumarate, bifunctional monomers such as divinylbenzene and alkylene glycol dimethacrylate are exemplified.

That is, even if the polystyrene resin used in the present invention is a homopolymer composed of only one of the styrene monomer components exemplified above, a plurality of monomer components exemplified above are combined. It may be a copolymer.
Furthermore, in this embodiment, a styrene copolymer containing another monomer component in addition to the monomer component can be adopted as the polystyrene resin.

By adopting more comonomer components having a high polarity as described above, the polystyrene resin obtained has a higher polarity and can be used as a polar resin component having a high SP value.
According to the Fedors equation, a general polystyrene-based resin shows a value of about 8.5 to 10 and is not a resin showing a very high SP value. It is said that resins whose values deviate by 0.5 to 1.0 or more are incompatible with each other. Usually, a PE resin has an SP value of around 8, so that a polyethylene resin or a polypropylene resin and the polystyrene are used. This is incompatible with the resin.

  Moreover, a matrix phase and a dispersed phase can be formed in a resin film by using together the polar resin component whose SP value is 9.0 or more with 1 or more types of the said nonpolar resin.

  Examples of resins that can be used as the polar resin component include acrylic resins and polylactic acid resins.

As the acrylic resin, a polymer obtained by using (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylamides, and (meth) acrylonitrile as main monomer components can be used.
The term “(meth) acryl” is used in the present specification to include both “methacryl” and “acryl”.

  More specifically, the monomer component constituting the acrylic resin includes acrylic acid, methacrylic acid: acrylic ester or methacrylic ester: for example, methyl acrylate, ethyl acrylate, n-propyl acrylate, acrylic acid Isopropyl, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, hexyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate, stearyl acrylate, palmityl acrylate, or cyclohexyl acrylate An alkyl ester of an alkyl group having 1 to 18 carbon atoms such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, Alkyl groups such as t-butyl tacrylate, hexyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate, stearyl methacrylate, palmityl methacrylate and cyclohexyl methacrylate have about 1 to 18 carbon atoms. The methacrylic acid alkyl ester is mentioned.

  Furthermore, as a monomer component constituting the acrylic resin, (meth) acrylic acid such as hydroxyethyl acrylate, hydroxyethyl methacrylate, hydroxypropyl acrylate, hydroxypropyl methacrylate, hydroxybutyl acrylate, hydroxybutyl methacrylate, etc. An alkyl ester having a hydroxyl group in the side chain of the (meth) acrylic acid side chain such as methoxybutyl acrylate, methoxybutyl methacrylate, methoxyethyl acrylate, methoxyethyl methacrylate, ethoxybutyl acrylate, ethoxybutyl methacrylate, etc. Alkyl ester having alkoxyl group; Alkenyl ester of (meth) acrylic acid such as allyl acrylate and allyl methacrylate; allyloxyethyl acrylate and allyloxyethyl methacrylate Alkenyloxyalkyl esters of (meth) acrylic acid such as glycidyl acrylate, glycidyl methacrylate, and alkyl esters having an epoxy group in the side chain of acrylic acid such as methyl glycidyl acrylate and methyl glycidyl methacrylate; diethylamino acrylate Mono- or di-alkylaminoalkyl esters of (meth) acrylic acid such as ethyl, diethylaminoethyl methacrylate, methylaminoethyl acrylate, methylaminoethyl methacrylate; silyl group, alkoxysilyl group or hydrolyzable alkoxy as side chain Examples include silicone-modified (meth) acrylic acid esters having a silyl group.

  In addition, examples of the monomer component constituting the acrylic resin include acrylamides or methacrylamides: for example, acrylamide; methacrylamide; (meth) acrylamide having a methylol group such as N-methylolacrylamide and N-methylolmethacrylamide; N (Meth) acrylamide having an alkoxymethylol group such as alkoxymethylolacrylamide (for example, N-isobutoxymethylolacrylamide) and N-alkoxymethylolmethacrylamide (for example, N-isobutoxymethylolmethacrylamide); N-butoxy Examples thereof include (meth) acrylamide having an alkoxyalkyl group such as methyl acrylamide and N-butoxymethyl methacrylamide.

In addition, various acrylic monomers such as acrylonitrile and methacrylonitrile can be cited as monomer components constituting the acrylic resin.

These monomer components can be used alone or in combination.
That is, even if the acrylic resin used in the present invention is a homopolymer composed only of any of the various monomer components exemplified above, a copolymer formed by combining a plurality of the various monomer components exemplified above. (Copolymer) may be used.
Furthermore, in this embodiment, a copolymer containing another monomer component in addition to the monomer component can be used as the acrylic resin.

  The monomer component other than those exemplified above is not particularly limited as long as it forms a copolymer with the monomer component. For example, vinyl acetate, vinyl chloride, vinylidene chloride, vinyl lactate, vinyl butyrate, versatic acid Examples thereof include vinyl monomers such as vinyl and vinyl benzoate, ethylene, butadiene, and styrene.

As the acrylic resin in the present embodiment, polymethyl methacrylate (PMMA) resin is suitable among those using one or more of the above acrylic monomer components, and a commercially available PMMA resin is available at a low price. This is also preferable from the viewpoint of ease.
Further, an ethylene-acrylic acid copolymer (EAA) resin is suitable as long as it is a copolymer of a monomer component other than the acrylic monomer and the acrylic monomer component.

  Examples of the polylactic acid (PLA) resin include poly D-lactic acid resin, poly L-lactic acid resin, poly D-lactic acid resin that is a copolymer of poly D-lactic acid and poly L-lactic acid, and poly D-lactic acid. Mixture of lactic acid resin and poly L-lactic acid resin (stereo complex), copolymer of poly D-lactic acid and hydroxycarboxylic acid, copolymer of poly L-lactic acid and hydroxycarboxylic acid, poly D-lactic acid or poly The copolymer of L-lactic acid, aliphatic dicarboxylic acid, and aliphatic diol can be mentioned, These can be made to contain in the said resin composition individually or in the state mixed together.

  In addition to these, resins that generally exhibit an SP value of 9.0 or more include polyvinyl chloride resins, polyvinyl alcohol resins, polyamide resins, and polyvinyl acetate resins.

The polymethyl methacrylate resin is generally said to have an SP value of about 9.1 to 9.5. For example, among the styrene resins called general-purpose polystyrene resin (GPPS), etc. A styrene homopolymer having a low SP value exhibits incompatibility with the acrylic resin and the polylactic acid resin.
Therefore, a specific combination of “two or more types of incompatible polymers” in the present invention includes “polyethylene resin, polypropylene resin, and mixed resin thereof”, “polystyrene resin, acrylic resin”. Examples thereof include a combination of a resin and any one of polylactic acid resins, and a combination of a “polystyrene resin” and an “acrylic resin or polylactic acid resin”.

  In the case where the matrix phase and the dispersed phase are formed by two or more kinds of resins having such incompatibility, as a polymer type antistatic agent having incompatibility with these, for example, the matrix phase is polar. If formed with a resin component and the dispersed phase is formed with a non-polar resin component, the solubility parameter is lower than the resin forming the matrix phase and has a higher solubility parameter than the resin forming the dispersed phase. By using a polymer-type antistatic agent having a polymer as a main component, the polymer-type antistatic agent can be more reliably surrounded by resin particles composed of nonpolar components, and the core-shell type dispersion The phase can be more reliably formed.

  Examples of the polymer-type antistatic agent include polyethylene oxide, polypropylene oxide, polyethylene glycol, polyester amide, polyether ester amide, ethylene-methacrylic acid copolymer ionomer (ionomer resin), polyethylene glycol methacrylate copolymer, and the like. And a copolymer of an olefin block and a hydrophilic block described in JP-A No. 2001-278985 and the like.

Among these, in consideration of the interaction with the resin exemplified above, a copolymer having an olefin block and a hydrophilic block is preferable, and a polyether-polyolefin block copolymer (a polyether block and a polyolefin block) is preferable. A polymer type antistatic agent having a block copolymer) as a main component can be preferably used.
In particular, the main component is a block copolymer of a polyolefin block containing 70 mol% or more of propylene and a polyether block.
Here, the “main component” means that the proportion of the above-mentioned polyether-polyolefin block copolymer in the polymer antistatic agent is 50% by mass or more.
The polyether-polyolefin block copolymer as described above is more preferably contained in an amount of 70% by mass or more, and particularly preferably 80% by mass or more in the polymer antistatic agent.
Furthermore, it is most preferable to use a polymer-type antistatic agent consisting essentially of the polyether-polyolefin block copolymer.

In order to enhance the antistatic effect, the resin composition for forming the resin film according to the present embodiment includes an anionic surfactant such as alkylbenzene sulfonate and sodium decylbenzene sulfonate, and the like. A low molecular weight antistatic agent such as a surfactant or an alkali metal salt may be used in combination.
However, the amount of ions eluted may increase with these additions, so the amount used is the total amount of antistatic agents (polymer antistatic agent + low molecular antistatic agent) contained in the resin composition. It is preferable to occupy less than 0.5% by mass.

The mixing ratio of the matrix phase forming resin and the dispersed phase forming resin in the resin composition of the present embodiment and the content of the polymer type antistatic agent are not particularly limited, but generally antistatic Since the surface resistivity of the resin film for which is required is preferably 1 × 10 ⁸ to 1 × 10 ¹³ Ω / □, such a composition that can impart such a surface resistivity to the resin film. Among them, it is preferable to select a blending ratio that can further reduce the content of the polymer antistatic agent.
The surface resistivity of the resin film is more preferably to either ^{1 × 10 9 ~1 × 10 12} Ω / □ , and be either ^{1 × 10 9 ~1 × 10 11} Ω / □ of the most preferable.
In order to give such a value of surface resistivity to the resin film, the preferable content of the resin for forming the dispersed phase is a proportion of the resin composition, usually 5 to 20% by mass, and 5 to 15% by mass. It is particularly preferred that

Moreover, the said polymer type antistatic agent is normally contained in the ratio from which the ratio which occupies for the whole resin composition becomes 2-30 mass%.
The reason why the lower limit of the polymer type antistatic agent is set to 2% by mass is that if the content is lower than this, the resin film may not exhibit sufficient antistatic effect. Yes, the upper limit is set to 30% by mass. Even if a polymer type antistatic agent is included exceeding this, not only is it difficult to obtain an antistatic effect corresponding to the content, but also the material of the resin film. This is because the cost may increase.
From this point of view, the polymer antistatic agent is preferably contained in a proportion of 3 to 20% by mass in the entire resin composition. It is particularly preferable that the occupying ratio is 5 to 10% by mass.

  Although not described in detail here, the resin composition used for forming the resin film of the present embodiment can contain a compounding agent used for forming a general polymer film. Various stabilizers such as anti-aging agents, processing aids such as lubricants, slip agents, antifogging agents, pigments, fillers and the like can be appropriately added as additives.

Although not described in detail here, the molded article of the present invention is not limited to the resin material as exemplified above, and can be formed using various polymers. For example, ethylene-propylene-dienter A low-polarity rubber such as a polymer (EPDM), butadiene rubber, polyisobutylene, or styrene-butadiene rubber can be used instead of a part or all of the nonpolar resin component, and the content of chloroprene and acrylonitrile A high nitrile rubber, an ethylene-vinyl acetate copolymer (EVA rubber) having a high vinyl acetate content, or the like may be used instead of a part or all of the polar resin component.
That is, not only a resin molded product but also a rubber molded product and a molded product formed of a composite material of rubber and resin are within the scope of the present invention.

Next, as a method for producing a molded product according to the present embodiment, a method for producing a resin film using the resin composition will be described.
In the present embodiment, a method used in a general film manufacturing method can be employed. For example, the resin (two or more kinds of mutually incompatible resins) and the polymer type antistatic agent are used. After carrying out the kneading step for producing the resin composition to be contained, a method for carrying out an extrusion step of extruding the obtained resin composition into a film can be adopted.
Below, each process is demonstrated more concretely.

(Kneading process)
First, for example, each of two or more types of incompatible resins such as a polyethylene resin and an acrylic resin, a polymer antistatic agent, and a slip agent or an antifogging agent as necessary After weighing the agent and dry blending with a tumbler blender, Henschel mixer, etc., each compounding material is almost uniformly mixed with a single screw extruder, multi-screw extruder, kneader, Banbury mixer, etc. To melt knead.
Thereafter, the kneaded product is extruded into a strand shape and pelletized, or hot cut and pelletized to produce pellets made of the resin composition.

(Extrusion process)
Examples of the method for extruding the pellets obtained in the kneading step into a film in a hot melt state include, for example, extrusion from a circular die and the like, and film formation by an inflation method, or extrusion from a T-die and the like to form a film by a casting method. The method of doing.
Of these, a flat die such as a T-die is easy to stretch in the extrusion direction but requires a facility such as a tenter for stretching in the width direction. It is preferable to carry out an extrusion process using a die.

At the time of mixing in the heat-melted state in the kneading step and the extrusion step, for example, if a resin composition containing a large excess of polyethylene resin relative to the acrylic resin is produced, a polyethylene resin having low polarity In contrast, an acrylic resin having a high polarity exhibits incompatibility, and a dispersed phase of the incompatible component is dispersed in a matrix phase containing the polyethylene resin.
That is, a sea-island structure in which a dispersed phase is formed from an acrylic resin is formed in the molten resin composition.
At this time, a copolymer (polymer antistatic agent) having a polyolefin block having a high affinity for the polyethylene resin and a polyether block having a high affinity for the acrylic resin is formed from the dispersed phase and the matrix. Aggregates at the interface with the phase to form a region with low electrical resistance along the interface.
That is, the acrylic resin is dispersed in the polyethylene resin, which is the base resin, while being covered with the polymer antistatic agent.

In addition, the core-shell-shaped particles having the acrylic resin particles as a core and the outer shell portion formed of a polymer-type antistatic agent, the flow direction of the resin due to the shearing force acting on the molten resin composition in the extrusion process. It extends long along (extrusion direction) and becomes a state with a comparatively high aspect ratio, and forms a dispersed phase.
And the state which this disperse phase extended long is maintained also in the resin film obtained by cooling while the molten resin composition flows.
For example, the surface resistivity can be remarkably lowered by forming elongated particles having a length of more than 1 μm in the dispersed phase.

To explain this further, the polymer antistatic agent is usually a polymer whose main component is excellent in ion conductivity as described above, and the surface resistivity is increased by imparting ion conductivity to the surface of the resin film. The antistatic agent is reduced to prevent static charge. However, when a polymer type antistatic agent is dispersed in, for example, a polyethylene resin alone, it is dispersed as fine dot-like particles in the system. The effect is not exerted unless the particles are contained in such an amount that the distance between the particles can be approached to some extent.
Here, in the present embodiment, particles in which the core portion is formed of acrylic resin particles and the outer shell portion (shell portion) is formed of a polymer type antistatic agent are formed.
From this, it is possible to reduce the inter-particle distance of the dispersed phase while suppressing the amount of the polymeric antistatic agent used by the amount of the core portion.

In addition, the particles forming the dispersed phase extend long along the flow direction (extrusion direction) of the resin, and the length in the film plane direction exceeds 1 μm. A conductive path is formed on the particle surface.
That is, in the resin film of this embodiment, since the dispersed phase is formed in the long and thin particles as described above along the resin flow direction, the electrical resistance value along the longitudinal direction of the particles is reduced. Will be.

In general, the electrical resistance value between core-shell particles forming a dispersed phase and other particles adjacent to the particles is mainly determined by the distance between the particles.
That is, when a voltage is applied in a direction perpendicular to the resin flow direction, the portion having the lowest electrical resistance value in the section where the core-shell particles are adjacent to each other (usually, the portion where the particles are closest to each other) The electrical resistance value will depend on the amount of charge flowing through.

And in the resin film of this embodiment, since the disperse phase is formed in a long and thin granular shape along the flow direction of the resin, the section where the particles are adjacent to each other is formed long, and the electric resistance value is low during that period. A possibility that a part will be formed becomes high.
Therefore, the electric resistance value can be reduced in directions other than the resin flow direction advantageous for ion conduction, and the blend amount of the polymer type antistatic agent is 30% by mass or less, for example, 5 to 10% by mass. The surface resistivity of the resin film can be lowered to a value of 10 ¹³ (Ω / □) order or less (less than 1 × 10 ¹⁴ ) which is generally required.

The effects as described above are manifested by the incompatibility of the polymer constituting the polymer type antistatic agent with the resin forming the matrix phase or the dispersed phase.
Whether or not these are incompatible can be determined by determining in advance the solubility parameters of the resin that forms the matrix phase and the resin that forms the dispersed phase, as described above. A polymer type antistatic agent having an SP value different from that of the resin by 0.5 or more, preferably 1.0 or more may be selected.
The solubility parameter is obtained from the molecular structure based on the Fedors equation. For example, when a commercially available polymer type antistatic agent is used, the structure cannot be specified sufficiently. If it is difficult to calculate, actually, the dispersion state of the sample obtained by heating, melting and mixing the resin and the polymer antistatic agent and cooling the sample is obtained by using a scanning electron microscope (SEM). ) Or a transmission electron microscope (TEM) and can be determined by direct observation.

Further, as a specific method for forming the core-shell-like particles having the outer shell formed with such a polymer type antistatic agent to be longer than 1 μm as described above, a method of adjusting the way of applying shear during extrusion Is mentioned.
The size of the dispersed phase can also be directly confirmed by SEM or TEM. For example, it is possible to observe about 10 fields of view randomly at a magnification of several thousand to several tens of thousands times with respect to a sample collected from a molded product. If a particle having a length of 1 μm or more can be confirmed in more than half of the visual fields, it can be determined that a dispersed phase of 1 μm or more is formed in the molded product.

As described above, the shape of the core-shell particles and the selection of the polymer antistatic agent that constitutes the outer shell of the particles make it possible to further suppress the amount of the polymer antistatic agent used in the resin film while reducing the surface resistivity. Reduction can be achieved.
Such a dispersed phase only needs to be formed at least on the surface of the resin film, and the shape and size of the dispersed phase in the film does not significantly affect the antistatic performance.
Therefore, when a thick resin film is required, for example, three-layer coextrusion is performed, and the central part is configured not to contain a polymer antistatic agent, so that the amount of polymer antistatic agent used is reduced. It is also possible to plan.

(Second embodiment)
Next, a sheet-like foamed molded product (foamed sheet) will be described as a second embodiment of the molded product of the present invention.
This foamed sheet can be produced by adding a foaming component to the resin composition described in the first embodiment and then extruding and foaming with an extruder.

  Examples of the component for foaming include a gas component, a bubble nucleating agent that becomes a nucleus when the gas component forms bubbles, and a compound particle that thermally decomposes to generate a gas.

  The bubble nucleating agent is not particularly limited as long as it is generally used as a bubble nucleating agent. For example, talc, mica, silica, diatomaceous earth, aluminum oxide, titanium oxide, zinc oxide, magnesium oxide, Examples include inorganic compounds such as magnesium hydroxide, aluminum hydroxide, calcium hydroxide, potassium carbonate, calcium carbonate, magnesium carbonate, potassium sulfate, barium sulfate, and glass beads, and organic compounds such as polytetrafluoroethylene. Talc is particularly preferable. In addition, a bubble nucleating agent may be used independently or 2 or more types may be used together.

  As the foaming agent used together with the cell nucleating agent, those conventionally used for foaming extrusion can also be employed in this embodiment. For example, water, hydrocarbon, dimethyl ether, methyl chloride, ethyl chloride, nitrogen Carbon dioxide, argon, etc. can be used.

  Moreover, as the compound particles that generate gas by thermal decomposition, for example, azodicarbonamide, sodium hydrogen carbonate, a mixture of sodium hydrogen carbonate and citric acid, or the like can be used.

  In order to obtain the foam sheet according to the present embodiment, for example, resin pellets containing a cell nucleating agent are produced in the same manner as in the kneading step in the first embodiment, and the gas component is extruded into a cylinder of the extruder at the time of extrusion. And a method of foaming and extruding from a circular die or a flat die provided at the tip of the extruder.

  Even in such a foam sheet, a matrix phase and a dispersed phase are formed on the surface, and the polymer-type antistatic agent forms a core-shell type dispersed phase constituting the outer shell. A high antistatic effect can be imparted at a used amount of.

Such a foam sheet suppresses bleed-out of the antistatic agent and can also prevent adhesion of dust and the like, so that a material such as a food tray, a tray for transporting and storing electrical / electronic components, and the tray It can be said that it is suitable as a material such as a partitioning material for partitioning the interior.
Moreover, since bleeding out of an antistatic agent is suppressed, it can be said that it is suitable also for uses, such as a cushion sheet interposed between glass plates.
That is, it is possible to prevent fogging of the glass plate due to bleed-out, and to prevent a situation where cleaning is required again, and to prevent the glass plate from being peeled off by static electricity when used. Is suitable as a cushion sheet.

In addition, when using a foam sheet with a film layer in which a film layer is formed on one side or both sides, as described above, as a food tray, a tray for transporting / preserving electric / electronic parts, a partition material, and a cushion sheet. Does not need to contain a polymer antistatic agent in the foam layer of the foam sheet with a film layer, and this film layer may be formed of a film as shown in the first embodiment.
In that case, by forming the foam layer and the film layer by coextrusion, not only a foam sheet with a film layer can be easily obtained, but also a molded product having excellent adhesive strength between the foam layer and the film layer. Can be obtained.

In this second embodiment, the point that a disperse phase extending in the extrusion direction is formed on the surface of the foamed sheet, and the point that is advantageous for lowering the surface resistivity by forming a disperse phase of 1 μm or more, As in the first embodiment, the shape of the dispersed phase can be controlled by adjusting the extrusion conditions as in the first embodiment.
In the second embodiment, the form of the dispersed phase can also be adjusted by adjusting the foaming degree.

Here, when producing what has a three-dimensional structure other than such a sheet-like foam molded article, two or more kinds of mutually incompatible polymers are contained, and any of the polymers is incompatible. It is possible to employ a method in which resin beads for foaming are produced with a resin composition containing the polymer type antistatic agent shown and foamed in a mold having a product shape for which the resin beads are desired.
Moreover, in this embodiment, as a method of obtaining a foam molded product, it is not limited to such a method, A various method is employable.

(Third embodiment)
Next, a case where an injection molded product is formed will be described as a third embodiment of the present invention.
In this embodiment, a method for obtaining a molded product by introducing resin pellets obtained in the same manner as in the kneading step in the first embodiment into a general injection molding machine is mentioned as a specific implementation method.
In the injection molding, the molten resin is cooled and solidified while being sheared by the inner wall surface of the cavity portion of the mold.
Therefore, the shape of the dispersed phase can be adjusted also by the shape of the gate.
In the present embodiment, since the molten resin composition is cooled while being in contact with the metal surface, the highly polar component contained in the resin composition is usually concentrated on the contact surface with the mold. Tend to be.
That is, for example, by adopting a highly polar resin such as an acrylic resin or a polylactic acid resin as a resin for forming a dispersed phase, more of these resin particles can be present on the surface of the molded product. The surface of the polymer antistatic agent surrounding the particles can also be concentrated.
Therefore, an excellent antistatic effect can be expected by using a smaller amount of the polymer antistatic agent.

  In addition, the method for producing a molded article by injection molding includes preparing a part in advance in a mold, and a part made of the member and a part made of a resin composition containing a polymer type antistatic agent. It can be said that this is an excellent method in that a composite molded product having the above can be easily obtained.

In the first embodiment to the third embodiment, the description is focused on the method of thermally melting the resin composition in that the matrix phase and the dispersed phase are easily formed on the surface of the molded product. For example, a resin solution is prepared by dissolving a resin composition in a solvent, and this is coated on a base material. Then, the solvent is removed, and the resin having a matrix phase and a dispersed phase on the base material surface Even in the case of coating, in the case of forming a core-shell type dispersed phase having an outer shell portion formed by a polymer-type antistatic agent, it is within the range intended as the method for producing a molded article of the present invention.
Further, as described above, in the present invention, the polymer composition is not limited to the resin composition, and even when a rubber composition is used, a dispersed phase is formed in the rubber forming the matrix phase, and the outer shell thereof is formed. Is formed of a polymer type antistatic agent, is within the scope of the present invention.

In addition, the molded article of the present invention is not limited to those exemplified in the present embodiment, and the above-described molded article includes two or more kinds of mutually incompatible polymers together with a polymer antistatic agent. As long as the dispersed phase is formed as core-shell particles having a polymer-type antistatic agent as an outer shell, for example, fibers, fiber products, and the like are also within the range intended as the molded product according to the present invention. .
Such a textile product can be suitably used, for example, as a seat covering material for automobiles or a lining material for clothes.
Furthermore, the molded article of the present invention can be employed in various applications where countermeasures against electrostatic charging have been conventionally demanded.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not limited to these.

(Molded product production example 1: polyolefin resin film)
(Combination agent)
Below, the example which produces a polyolefin-type resin film as a molded article is demonstrated.
First, the abbreviations and details of the compounding agents used are described below.

(Preliminary study: Reference Examples 1-6)
Below, as shown in Table 1 below, a film-like sample is prepared using a polyolefin resin, a polar resin (PMMA, PLA), and a resin obtained by melt-mixing them, and the obtained film-like sample On the other hand, the value of surface resistivity was measured by the method described in JIS K 6911: 1995 “Thermosetting Plastics—General Test Method”.
The results are also shown in Table 1 below.

Specifically, a flat square test piece having a side of 10 cm is left in an atmosphere at a temperature of 22 ° C. and a humidity of 60% for 24 hours, and then tested in an environment of a temperature of 22 ° C. and a humidity of 60%. Using a digital ultra-high resistance / microammeter R8340 and a resiliency chamber R12702A) manufactured by the company, an electrode is crimped to the test piece with a load of about 30 N, and a voltage of 500 V is applied and resistance after one minute has passed. The value was measured and calculated by the following formula.
ρs = π (D + d) / (D−d) × Rs
However,
ρs: Surface resistivity (Ω / □)
D: Inner diameter (cm) of the annular electrode on the surface (7 cm for the resiliency chamber R12702A)
d: outer diameter (cm) of inner circle of surface electrode (5 cm for resiliency chamber R12702A)
Rs: Surface resistance (Ω)

Moreover, measurement was implemented 3 times and each arithmetic mean value was calculated | required.

(Surface TEM observation)
FIGS. 10 and 11 show the thin film samples cut out of the resin films of Reference Examples 5 and 6 as observed with a transmission electron microscope (TEM).
Note that the test piece in the TEM observation is a slice of the resin film along the extrusion direction, and the TEM images shown in these figures are the sliced test on the side corresponding to the surface of the resin film. A piece is observed.
That is, the state in the vicinity of the surface side in the cross section in the thickness direction of the resin film is observed from the direction orthogonal to the extrusion direction.
From these figures, it can be seen that a polyolefin resin is used as a matrix phase, and PMMA and PLA form a dispersed phase having a high aspect ratio.

As shown in this preliminary study, films made of resins with high polarity, such as PMMA and PLA, have high surface resistivity as well as films made of polyolefin resins with low polarity, and are easily charged. It is.
In addition, the present invention is characterized in that a resin that is incompatible with the base resin is used in combination with a polymer-type antistatic agent. However, a polar polymer is simply obtained by melting and mixing a highly polar resin with a polyolefin resin. It can also be seen from the results of FIGS. 10 and 11 and Table 1 that the antistatic performance cannot be improved only by forming a dispersed phase having a high aspect ratio due to the above in a matrix phase made of a polyolefin resin.

(Formulations 1 to 4)
Next, a polyolefin resin film having the thickness shown in Table 2 was prepared according to the formulation shown in Table 2 below, and the surface resistivity was measured in the same manner as in Reference Examples 1-6. The surface resistivity was measured only on one side of the polyolefin resin film. The results are also shown in Table 2.

  As will be described in detail later, in a film obtained by melting and mixing an acrylic resin and a polymer antistatic agent with this polyolefin resin, an outer shell is formed with the polymer antistatic agent. It was confirmed that core-shell-like particles having an inner core formed of the acrylic resin were formed.

As shown in Table 2, the formulation 2 with a reduced amount of the polymer antistatic agent compared to the standard formulation (compound 1) in which the polymer antistatic agent is simply blended has a large surface resistivity. While increasing the value, when the ethylene-acrylic acid copolymer (A210K) or PMMA resin (LG35) is used in combination (formulations 3 and 4), the polymer antistatic agent is reduced in weight. However, the surface resistivity can be greatly reduced.
In addition, when the PMMA resin (LG35) having an MFR of 30 g / 10 min or more is used in combination with the polymer-type antistatic agent (Pelestat 230), it can be seen that the decrease in surface resistivity (antistatic effect) is large. .

(Formulation 5-7)
A polyolefin resin film having the thickness shown in Table 3 was prepared with the formulation shown in Table 3, and the surface resistivity was measured in the same manner as in formulations 1 to 4. The surface resistivity was measured only on one side of the polyolefin resin film. The results are also shown in Table 3.

  Table 3 also shows that the use of an acrylic resin (PMMA) together can reduce the surface resistivity of the polyolefin resin film while suppressing the use of the polymer antistatic agent.

(Formulations 8-11)
Similarly, polyolefin resin films having the thicknesses shown in Table 4 were prepared with the formulations shown in Table 4 (Formulations 8 to 11), and the surface resistivity was measured. The surface resistivity was measured only on one side of the polyolefin resin film. The results are also shown in Table 4.

  Table 4 also shows that the use of an acrylic resin (PMMA) can reduce the surface resistivity of the polyolefin resin film while suppressing the use of the polymer antistatic agent.

(Formulations 12-17)
A polyolefin resin film having the thickness shown in Table 5 was prepared with the formulation shown in Table 5 (Formulations 12 to 17), and the surface resistivity was measured. The surface resistivity was measured only on one side of the polyolefin resin film. The results are also shown in Table 5.
Table 5 also shows that the use of the acrylic resin (PMMA) can reduce the surface resistivity of the polyolefin resin film while suppressing the use of the polymer antistatic agent.

(Graph 1)
Based on PL500A (manufactured by Sun Allomer, Homo PP, MFR ^(M) = 3.3 g / 10 min), a system containing 10% by weight of LG35 and a system containing 10% by weight of CM-50 FIG. 1 shows a graph of changes in the surface resistivity when the molecular type antistatic agent (Pelestat 230) is varied.
In addition, in the case where acrylic resin such as LG35 or CM-50 is not contained, the value of the surface resistivity when only the polymer type antistatic agent is contained by 12 wt% (PL500A: 88 wt%) is also included. ("X" in the figure).
From the extrapolation line shown in this graph 1, by adding an acrylic resin, compared with the case where only the polymer type antistatic agent is used, the equivalent surface resistance even when the content is about 2/3. It can be seen that the rate value can be obtained.

(Graph 2)
Based on PL500A (manufactured by Sun Allomer, Homo PP, MFR ^(M) = 3.3 g / 10 min), a system containing 10% by weight of LG35, a system containing 10% by weight of 560F, and 10% by weight of EH FIG. 2 shows a graph of changes in surface resistivity when the polymer type antistatic agent (Irgastat P18) in a system containing 1% is varied.
Further, when an acrylic resin such as LG35 is not contained, only 5% by weight, 7% by weight, and 12% by weight of the polymer type antistatic agent (PL500A: 95% by weight, 93% by weight, and 88% by weight). %) The value of the surface resistivity when it is contained is also shown (“×” in the figure).
From this graph 2, it can be seen that when a polymer type antistatic agent having an MFR of 10 g / 10 min is used, the surface using the 560F or EH having a lower MFR than the LG35 having an MFR of 30 g / 10 min or more is used. It turns out that it is effective for the fall of the value of resistivity.

(Surface TEM observation)
Observation with a transmission electron microscope (TEM) of a thin piece sample prepared by extruding a polyolefin resin composition containing 10% by weight of PMMA and 7% by weight of Pelestat 230 in a melted state in a heated state This is shown in FIG.
Note that the test piece in the TEM observation is a slice of a polyolefin resin film along the extrusion direction, and the TEM image in FIG. 3 is the sliced test piece on the side corresponding to the surface of the polyolefin resin film. Is observed.
That is, the state in the vicinity of the surface side in the cross section in the thickness direction of the polyolefin-based resin film is observed from the direction orthogonal to the extrusion direction.
FIG. 3 also shows that on the surface of the polyolefin resin film, the polyolefin resin is used as a matrix phase, and PMMA forms a dispersed phase having a high aspect ratio.
Further, it can be seen that perestert, which is a polymer type antistatic agent, is assembled in a state of forming an outer shell around the PMMA.
This also shows that according to the present invention, it is possible to achieve antistatic while reducing the amount of the polymeric antistatic agent used in the polyolefin resin film.

(Molded product production example 2: Polyolefin resin foam sheet)
Since the used compounding agent is common with “Molded product production example 1”, the description thereof will be omitted, and the following description will be made using abbreviations.
(Formulations 18-23)
A polyolefin-based resin foam sheet having the thickness shown in Table 6 was prepared with the formulation shown in Table 6, and the surface resistivity was measured in the same manner as in the previous evaluation examples. The results are also shown in Table 6.
In addition, the temperature and humidity environment were changed to three conditions of (21 ° C., 57% RH), (20 ° C., 30% RH), and (21 ° C., 85% RH), and the data obtained by measuring the surface resistivity were also combined. Table 6 shows.

Table 6 also shows that the use of the acrylic resin (PMMA) together can reduce the surface resistivity value of the polyolefin resin foam molded article while suppressing the use of the polymer antistatic agent.
Moreover, when the PMMA resin (LG35) having an MFR of 30 g / 10 min or more is used in combination with the polymer type antistatic agent (Perestat 230), the PMMA resin (560F) having an MFR of 13 g / 10 min is used in combination. It can also be seen that the decrease in surface resistivity (antistatic effect) is greater than that of

(Molded product production example 3: polyolefin resin molded product)
Since the used compounding agent is common with “Molded product production example 1”, the description thereof will be omitted, and the following description will be made using abbreviations.
(Formulation 24-29)
Next, evaluation examples of polyolefin resin molded products are shown.
First, a polyolefin resin composition having the composition shown in Table 7 below was prepared. This polyolefin resin composition was produced by kneading each material with a twin screw extruder and pelletizing.
This pellet (polyolefin resin composition) was injection molded to produce a 20 mm × 30 mm × 4 mm sheet (non-foamed) polyolefin resin molded product.
The following evaluation was implemented with respect to the obtained polyolefin resin molded product.

(Evaluation method)
Moreover, after leaving the obtained sheet-like polyolefin-based resin molded product in an environment of a temperature of 22 ° C. and a relative humidity of 60% for 24 hours, an environment of a temperature of 22 ° C. and a relative humidity of 60%, manufactured by Mitsubishi Chemical Corporation, The surface resistivity value was measured using a high resistivity meter, “High Lester UP” (MCP-HT450, probe: URS).
In the measurement, a method was adopted in which the probe was pressed against the surface of a sheet-like polyolefin resin molded article and a surface resistivity value was measured after applying a voltage of DC 500 V for 1 minute.
Moreover, the measurement was implemented with respect to three polyolefin resin molded products, and the arithmetic average of these was made into the surface resistivity of each reference example and a comparative example.
The results are also shown in Table 7.

  As shown in Table 7, in the formulations 26 and 29 in which the polymer type antistatic agent was reduced by about half compared to the reference formulation (compounds 25 and 28), the surface resistivity value was greatly increased. The surface resistivity values are almost the same as those of the blends 24 and 27 of the polymer (PF814, PL500A) alone.

(Formulation 30-35)
A polyolefin resin composition having the composition shown in Table 8 below was prepared. This polyolefin resin composition was produced by kneading each material with a twin screw extruder and pelletizing.
This pellet (polyolefin resin composition) was injection molded to produce a 20 mm × 30 mm × 4 mm sheet (non-foamed) polyolefin resin molded product.
With respect to the obtained polyolefin-based resin molded product, the value of the surface resistivity was measured in the same manner as in the above-mentioned blending 24-29.
The results are also shown in Table 8.

  As shown in Table 8, blends 30 and 32 in which the polymer type antistatic agent is reduced by about half compared to the previous standard blend (formulations 25 and 28), and blend 31 in which the ratio is 1/4 or less, A comparatively low surface resistivity value is also observed in 33 and the like, and it can be seen that an excellent antistatic effect is obtained with the addition of LG35 (PMMA) with a small amount of antistatic agent.

(Molded product production example 4: polyolefin resin film)
(Formulation 36-38)
With the formulation shown in Table 9 below, a polyolefin resin film having the thickness shown in Table 9 was prepared with an extruder, and the polyolefin resin film was evaluated in the same manner as in “Production Example 1 of Molded Product”.
With respect to the compounding agents used, those common to “Manufacturing Example 1 of Molded Article” will not be described, and will be described below using abbreviations.

  As shown in Table 9, the formulation 37 with a reduced amount of the polymer antistatic agent compared to the standard formulation (compound 36) in which the polymer antistatic agent is simply blended has a large surface resistivity. While the value is increased, when the HV6250 is used in combination (Formulation 38), the surface resistivity can be greatly decreased even if the amount of the polymer antistatic agent is decreased.

(Formulation 39-41)
A polyolefin resin film having the thickness shown in Table 10 was prepared with the formulation shown in Table 10, and the surface resistivity was measured as before. The surface resistivity was measured only on one side of the polyolefin resin film. The results are also shown in Table 10.

  Table 10 also shows that the use of a polylactic acid resin (PLA) can reduce the surface resistivity of the polyolefin resin film while suppressing the use of the polymer antistatic agent.

(Surface TEM observation)
A thin piece sample prepared by using a polyolefin resin composition containing 10% by weight of polylactic acid resin and 7% by weight of perestert 230 and extruded in the form of a sheet in the state of being melted by heating was subjected to a transmission electron microscope (TEM). FIG. 4 shows the state observed in FIG.
The test piece in the TEM observation is a slice of a polyolefin resin film along the extrusion direction, and the TEM image in FIG. 4 is the sliced test piece on the side corresponding to the surface of the polyolefin resin film. Is observed.
That is, the state in the vicinity of the surface side in the cross section in the thickness direction of the polyolefin-based resin film is observed from the direction orthogonal to the extrusion direction.
The disperse phase observed in the TEM image of FIG. 4 is formed of a polylactic acid resin, and the periphery of the polylactic acid resin is blacked out by Pereztat 230.
The scale bar provided below the TEM image represents a length of 0.5 μm. From FIG. 4 as well, the polylactic acid resin forms a dispersed phase with a high aspect ratio, and a polymer around it. It can be seen that pelletstat 230, which is a mold antistatic agent, is assembled.
This also shows that according to the present invention, it is possible to prevent the charge while reducing the amount of the polymer antistatic agent used.

(Molded product production example 5: polyolefin resin foam sheet)
(Formulation 42-44)
With the formulation shown in Table 11 below, a polyolefin resin foam sheet having the thickness shown in Table 11 was prepared with an extruder, and the polyolefin resin foam sheet was evaluated in the same manner as in Production Example 1.
In addition, since the used compounding agent is common to the conventional molded product manufacturing examples, the description thereof will be omitted, and the following description will be made using abbreviations.
The surface resistivity was measured on both the front and back surfaces of the polyolefin resin foam sheet. The results are also shown in Table 11.

Table 11 also shows that the use of a polylactic acid resin (PLA) can reduce the surface resistivity value of the polyolefin resin foam molded article while suppressing the use of the polymer antistatic agent.
It can also be seen from Table 11 that the antistatic effect becomes more prominent when polylactic acid is contained in an amount of 5% by weight or more.

(Molded product production example 6: Polyolefin resin molded product)
(Formulation 45-50)
A polyolefin resin composition having the formulation shown in Table 12 was prepared according to the formulation shown in Table 12 below. This polyolefin resin composition was produced by kneading each material with a twin screw extruder and pelletizing.
This pellet (polyolefin resin composition) was injection molded to produce a 20 mm × 30 mm × 4 mm sheet (non-foamed) polyolefin resin molded product.
The obtained polyolefin resin molded product was evaluated in the same manner as in Production Example 3.
The results are also shown in Table 12.

  As shown in Table 12, in the formulations 47 and 50 in which the polymer type antistatic agent was reduced by about half compared to the reference formulation (compounds 46 and 49), the surface resistivity was greatly increased. The surface resistivity values are almost the same as those of the blends 45 and 48 of the polymer (PF814, PL500A) alone.

(Formulations 51-56)
A polyolefin resin composition having the composition shown in Table 13 below was prepared. This polyolefin resin composition was produced by kneading each material with a twin screw extruder and pelletizing.
This pellet (polyolefin resin composition) was injection molded to produce a 20 mm × 30 mm × 4 mm sheet (non-foamed) polyolefin resin molded product.
The surface resistivity of the obtained polyolefin resin molded product was measured as before.
The results are also shown in Table 13.

  As shown in Table 13, blends 51 and 53 in which the polymer type antistatic agent is reduced by about half compared to the above-described standard blend (blends 46 and 49), and blend 52 and ¼ or less, A comparatively low surface resistivity value is also observed in 54 and the like, and it can be seen that an excellent antistatic effect is obtained with a small amount of antistatic agent.

(Molded product production example 7: Polyolefin resin film)
(Formulation 57-67)
With the formulations shown in Tables 14 and 15, polyolefin resin films having the thicknesses shown in Tables 14 and 15 were prepared using an extruder, and the polyolefin resin films were evaluated in the same manner as in Production Example 1.
Regarding the compounding agents used, explanations of those common to the past will be omitted, and in the following, explanation will be given using abbreviations.
Here, the following compounding agents were further used.
(Combination agent)

From Table 14, it can be seen that the polymer-type antistatic agent does not exhibit the function of preventing antistatic until a certain amount is added.
And, in the blend 58 in which the amount of the polymer type antistatic agent is simply reduced compared to the reference blend (blend 57), the surface resistivity value is greatly increased. On the other hand, as shown in the blends 61 to 65, polystyrene ( When using PS) resin together, or when using acrylic resin (PMMA) or polylactic acid (PLA) resin as shown in Formulations 66 and 67, use a polymer antistatic agent. Even if the amount is reduced, the value of the surface resistivity can be lowered.
Furthermore, it can be seen from the above table that the surface resistivity can be further reduced by changing the polystyrene (PS) resin to be used to one having a high MFR value.
For example, when “HF77”, “679”, and “AGI02” having an MFR of 7.0 g / min or more are used (Formulation 63 to 65), “G9305” having an MFR of 1.5 g / min, or an MFR of 2 It can be seen from Table 15 above that better results are obtained than when “E641N” of 0.7 g / min is used (Formulations 61 and 62).

(TEM observation)
A thin piece sample produced by using a polyolefin resin composition containing 10% by weight of polystyrene (PS) resin and 7% by weight of perestert 230 and extruded into a sheet in a state of being melted by heating is a transmission electron microscope. The state observed with (TEM) is shown in FIG.
FIG. 5 also shows that PS forms a dispersed phase with a high aspect ratio, and perestert, which is a polymer antistatic agent, is gathered around the PS.
This also shows that according to the present invention, it is possible to prevent the charge while reducing the amount of the polymer antistatic agent used.

(Molded product production example 8: Polyolefin resin foam sheet)
(Formulation 68-72)
A polyolefin resin foam sheet having the thickness shown in Table 16 was prepared by an extruder with the formulation shown in Table 16 below, and the polyolefin resin foam sheet was evaluated in the same manner as in Production Example 1.
In addition, about the used compounding agent, the description is abbreviate | omitted about what is common in the previous molded article manufacture example, and it demonstrates using an abbreviation below.
This time, the following compounding agents were further used.

(Combination agent)

  Table 16 also shows that the use of a polystyrene resin (GPPS, HIPS) can reduce the surface resistivity value of the polyolefin resin foam molded article while suppressing the use of the polymer antistatic agent. .

(TEM observation)
A thin piece sample prepared by using a polyolefin resin composition containing 10% by weight of a polystyrene resin and 6% by weight of peresut 230 and foam-extruded into a sheet in a state of being melted by heating was subjected to a transmission electron microscope (TEM). FIG. 6 shows the state observed in FIG.
Also from FIG. 6, it can be seen that the polystyrene resin forms a dispersed phase having a high aspect ratio, and the peridot which is a polymer type antistatic agent is gathered around it to form an outer shell.

(Molded product production example 9: Polyolefin resin molded product)
(Formulation 73-76)
A polyolefin-based resin composition having the formulation shown in Table 17 was prepared using the formulation shown in Table 17 below. This polyolefin resin composition was produced by kneading each material with a twin screw extruder and pelletizing.
This pellet (polyolefin resin composition) was injection molded to produce a 20 mm × 30 mm × 4 mm sheet (non-foamed) polyolefin resin molded product.
Evaluation similar to the manufacture example 3 was implemented with respect to the obtained polyolefin resin molded product.
The results are also shown in Table 17.
In addition, in the said case, in addition to the conventional compounding agent, the following compounding agents were used.

(Combination agent)

  As shown in Table 17, the values of the surface resistivity are greatly increased in the formulations 75 and 76 in which the polymer type antistatic agent is reduced by about half compared to the reference formulation (compounds 73 and 74). .

(Formulation 77-81)
A polyolefin resin composition having the composition shown in Table 18 below was prepared. This polyolefin resin composition was produced by kneading each material with a twin screw extruder and pelletizing.
This pellet (polyolefin resin composition) was injection molded to produce a 20 mm × 30 mm × 4 mm sheet (non-foamed) polyolefin resin molded product.
The surface resistivity of the obtained polyolefin resin molded product was measured as before.
The results are also shown in Table 18.

  As shown in Table 18, a relatively low surface resistivity value was observed even when the polymer type antistatic agent was reduced by about half compared to the above-mentioned standard formulation (Formulations 73 and 74). It can be seen that an excellent antistatic effect is obtained with a small amount of the antistatic agent.

(Manufacturing Example 10 of Molded Product: Polystyrene Resin Film)
(Formulation 82-88)
With the formulation shown in Table 19 below, a polystyrene resin film having the thickness shown in Table 19 was produced with an extruder, and the polystyrene resin film was evaluated in the same manner as in Production Example 1.
In addition, about the used compounding agent, the description is abbreviate | omitted about what is common in the previous molded article manufacture example, and it demonstrates using an abbreviation below.
This time, the following compounding agents were further used.

(Combination agent)

As shown in Table 19, the surface resistivity can be greatly reduced by blending a certain amount of the polymer antistatic agent (blending 83) with the polystyrene resin alone (blending 82). it can.
Then, simply reducing the amount of the polymer antistatic agent (formulation 83 → formula 84) greatly increases the value of the surface resistivity.
On the other hand, in the formulations 85 to 88, even if the polymer type antistatic agent is halved (13% → 7%), it has the same surface resistivity.
That is, according to the present invention, it can be seen from the above results that antistatic can be achieved while reducing the amount of the polymer antistatic agent used.

(Blend 89-95)
Polystyrene resin films having the thicknesses shown in Table 20 were prepared with the formulation shown in Table 20 below.
Moreover, the value of surface resistivity was measured with respect to the obtained polystyrene-type resin film similarly to previous evaluation.
The results are also shown in Table 20.

From the results shown in Table 20, it can be seen that according to the present invention, the antistatic agent can be prevented while reducing the amount of the polymer antistatic agent used.
Further, when the results of Formulation 95 and Formulation 91 are compared, the value of the surface resistivity of Formulation 91 is lower, and the result of “G9305” with an MFR of 2 g / 10 min or less is higher than that of MFR. Is better than “HRM18” of 5 g / 10 min.

(TEM observation)
Using a transmission electron microscope (TEM), a thin piece sample was prepared by using a polystyrene resin composition having 10% by weight of a polypropylene resin and 7% by weight of perestat 230 and extruded into a sheet in a state of being heated and melted. The observed state is shown in FIG.
Also from FIG. 7, it can be seen that the polypropylene-based resin forms a dispersed phase having a high aspect ratio, and perestert which is a polymer type antistatic agent is gathered around the polypropylene resin.

(Molded product production example 11: polystyrene resin foam sheet)
(Formulation 96-101)
With the formulation shown in Table 21 below, a polystyrene resin foam sheet having the thickness shown in Table 21 was prepared with an extruder, and the polystyrene resin foam sheet was evaluated in the same manner as in Production Example 1.
In addition, since the used compounding agent is common to the conventional molded product manufacturing examples, the description thereof will be omitted, and the following description will be made using abbreviations.
The results are also shown in Table 21.

From the results shown in Table 21, it can be seen that according to the present invention, the antistatic agent can be prevented while reducing the amount of the polymer antistatic agent used.
Further, when Formulation 97 and Formulation 101 are compared, Formulation 97 has a lower surface resistivity value, and the MFR is less than 2 g / 10 min. The result with “G9305” is 5 g of MFR. / 10 min compared to “HRM18”.

(Molded product production example 12: Polystyrene resin molded product)
(Formulations 102-107)
Polystyrene resin compositions were prepared according to the formulation shown in Table 22 below. This polystyrene-based resin composition was prepared by kneading each material with a twin screw extruder and pelletizing.
This pellet (polystyrene resin composition) was injection-molded to produce a 20 mm × 30 mm × 4 mm sheet (non-foamed) polystyrene resin molded product.
Evaluation similar to the manufacture example 3 was implemented with respect to the obtained polystyrene-type resin molded product.
The results are also shown in Table 22.

As shown in Table 22, the surface resistivity value is greatly increased in the blends 104 and 105 in which the polymer type antistatic agent is reduced by half compared to the reference blend (compositions 102 and 103). .
The tendency was the same for different polymer type antistatic agents “Pelestat 300”.

(Formulation 108-112)
Polystyrene resin compositions having the composition shown in Table 23 below were prepared. This polystyrene-based resin composition was prepared by kneading each material with a twin screw extruder and pelletizing.
This pellet (polystyrene resin composition) was injection-molded to produce a 20 mm × 30 mm × 4 mm sheet (non-foamed) polystyrene resin molded product.
The surface resistivity of the obtained polystyrene-based resin molded product was measured as before.
The results are also shown in Table 23.

  As shown in Table 23, a relatively low value of surface resistivity was observed even when the polymer type antistatic agent was reduced by about half compared to the above-mentioned standard formulation (Formulations 102 and 103). It can be seen that an excellent antistatic effect is obtained with a small amount of the antistatic agent.

(Molded product production example 13: Polylactic acid resin film)
(Formulations 113-119)
With the formulation shown in Table 24 below, a polylactic acid resin film having the thickness shown in Table 24 was produced with an extruder, and the polylactic acid resin film was evaluated in the same manner as in Production Example 1.
Regarding the compounding agents used, explanations of those common to the past will be omitted, and in the following, explanation will be given using abbreviations.
In this study, the following compounding agents are further used.

(Combination agent)

  As shown in Table 24, when a polyolefin resin or a polystyrene resin is used in combination (composition 114 to 119) as compared with a reference composition (compound 113) in which a polymer type antistatic agent is simply blended. ), The surface resistivity can be greatly reduced even when the same amount of the polymer antistatic agent is used.

(Surface TEM observation)
A polylactic acid resin composition containing 10% by mass of PE (LF580) and 8% by mass of a polymer type antistatic agent (Pelestat 230) was produced by extruding it into a film in a melted state. FIG. 8 shows a state in which the thin sample was observed with a transmission electron microscope (TEM).
In addition, the test piece in the TEM observation is a slice of a polylactic acid resin film along the extrusion direction, and the TEM image in FIG. 8 was sliced on the side corresponding to the surface of the polylactic acid resin film. The test piece was observed.
That is, the state in the vicinity of the surface side in the cross section in the thickness direction of the polylactic acid-based resin film is observed from the direction orthogonal to the extrusion direction.
FIG. 8 also shows that PE forms a dispersed phase with a high aspect ratio, and perestert, which is a polymer antistatic agent, is gathered around the PE.
This also shows that according to the present invention, antistatic can be achieved while reducing the amount of the polymeric antistatic agent used in the polylactic acid resin film or laminated sheet.

(Molded product production example 14: Polylactic acid resin foam sheet)
(Formulation 120-123)
A polylactic acid resin film having the thickness shown in Table 25 was prepared by an extruder with the formulation shown in Table 25 below, and the polylactic acid resin film was evaluated in the same manner as in Production Example 1.
About the used compounding agent, since it is common so far, the description is omitted, and it demonstrates using an abbreviation below.

  From Table 25, it can be seen that the surface resistivity value of the polylactic acid resin foamed molded article can be lowered while suppressing the use of the polymer antistatic agent by using the polyolefin resin or polystyrene resin together. .

(Surface TEM observation)
A slice sample was cut out from a polylactic acid resin foam sheet that was extruded and foamed into a sheet in a state where the polylactic acid resin composition containing 10% by weight of PP resin and 7% by weight of “Pelestat 230” was heated and melted. FIG. 9 shows a state where the thin piece sample was observed with a transmission electron microscope (TEM).
Note that the test piece in the TEM observation is a slice of a polylactic acid resin foam sheet along the extrusion direction, and the TEM image in FIG. 9 is the slice on the side corresponding to the surface of the polylactic acid resin foam sheet. The observed test piece was observed.
That is, the state in the vicinity of the surface side in the cross section in the thickness direction of the polylactic acid-based resin foamed sheet is observed from a direction orthogonal to the extrusion direction.
Also from FIG. 9, it can be seen that the PP resin forms a dispersed phase with a high aspect ratio having a length of 1 μm or more, and the polymer type antistatic agent “Pelestat 230” is gathered around it. .

(Molded product production example 15: Polylactic acid resin molded product)
(Formulations 124-134)
A polylactic acid resin composition was prepared according to the formulation shown in Table 26 below. This polylactic acid resin composition was prepared by kneading each material with a twin screw extruder and pelletizing.
This pellet (polylactic acid resin composition) was injection-molded to produce a 20 mm × 30 mm × 4 mm sheet (non-foamed) polylactic acid resin molded product.
Evaluation similar to the manufacture example 3 was implemented with respect to the obtained polylactic acid-type resin molded product.
The results are also shown in Table 26.

  Also from Table 26, it can be seen that the surface resistivity value of the polylactic acid resin molded product can be lowered while suppressing the use of the polymer type antistatic agent by using the polyolefin resin or the polystyrene resin together.

Claims (6)

A molded article in which at least a part of the surface is formed by a polymer composition containing a polymeric antistatic agent,
It is a sheet-like foam molded product that is interposed between glass plates and used as a cushion sheet,
Two or more types of mutually incompatible polymers are contained in the polymer composition, and a matrix phase and a dispersed phase dispersed in the matrix phase are formed on the surface in contact with the glass plate , and As the polymer antistatic agent, a core-shell particle having a polymer antistatic agent that is incompatible with both the matrix phase and the dispersed phase and having the polymer antistatic agent as an outer shell The dispersed phase is formed, and the dispersed phase contains the core-shell particles having a length in the plane direction of the surface exceeding 1 μm. Either one of the matrix phase and the dispersed phase is composed of one or more of a polyethylene resin or a polypropylene resin, and the other is one or more of a polystyrene resin, an acrylic resin or a polylactic acid resin. The molded article according to claim 1 , wherein the molded antistatic agent comprises a block copolymer having a polyether block and a polyolefin block in the molecule . Either one of the matrix phase and the dispersed phase is composed of a polystyrene-based resin, the other is composed of a polylactic acid-based resin, and the polymer antistatic agent has a polyether block and a polyolefin block in the molecule. The molded article of Claim 1 containing the block copolymer which has these. A method for producing a molded article in which at least a part of a surface is formed by a polymer composition containing a polymer type antistatic agent,
The molded product to be manufactured is a sheet-like foam molded product that is interposed between glass plates and used as a cushion sheet,
By using the polymer composition containing two or more types of incompatible polymers, a matrix phase and a dispersed phase dispersed in the matrix phase are formed on the surface in contact with the glass plate , and As the polymer type antistatic agent, a polymer type antistatic agent that is incompatible with both the matrix phase and the dispersed phase is used, and a core-shell shape using the polymer type antistatic agent as an outer shell. A method for producing a molded article, wherein the dispersed phase is formed so as to be particles, and the core-shell particles having a length in the plane direction of the surface exceeding 1 μm are formed. As the polymer antistatic agent, a polymer antistatic agent containing a block copolymer having a polyether block and a polyolefin block in the molecule is used, and either the matrix phase or the dispersed phase is used. The molded article according to claim 4 , wherein one is formed of one or more of a polyethylene resin or a polypropylene resin and the other is formed of one or more of a polystyrene resin, an acrylic resin, or a polylactic acid resin. Method. As the polymer antistatic agent, a polymer antistatic agent containing a block copolymer having a polyether block and a polyolefin block in the molecule is used, and either the matrix phase or the dispersed phase is used. The method for producing a molded article according to claim 4 , wherein one is made of a polystyrene-based resin and the other is made of a polylactic acid-based resin.