JP5802851B2 - Method for producing antistatic pressure-sensitive adhesive composition - Google Patents

Description

The present invention generally relates to a method for producing an antistatic pressure-sensitive adhesive composition having excellent antistatic properties, and more specifically, an antistatic pressure-sensitive adhesive composition improved so as not to cause bleeding or blooming. concerning the production method.

  In recent years, it has become important to impart antistatic properties to resins. To achieve this, antistatic agents such as surfactants have been conventionally applied to the surface of resin molded products, or antistatic properties have been achieved. A method of kneading an agent into a resin is known. However, in the former method, the antistatic property is remarkably lowered after a long time, so that it is difficult to put it into practical use as a highly antistatic resin having durability. On the other hand, in the latter method, the compatibility between the antistatic agent and the resin is poor, and the antistatic agent is peeled off from the surface of the molded product, or bleeding or blooming occurs.

  Antistatic agents such as surfactants are dependent on humidity, and at low humidity, the antistatic effect is deactivated, or after molding the resin, the antistatic effect is at least 1 to It took 3 days and there was a problem that it was slow-acting.

  In addition, a method of kneading carbon black or carbon fiber into a resin has been proposed. According to this method, a resin composition having excellent antistatic properties and durability in antistatic properties can be obtained. However, this method has a problem that a transparent molded product cannot be obtained, and selection of the color of the molded product is restricted.

  As a method for solving the above problems, the present inventors have prepared a solution in which a metal salt composed of a cation that is an alkali metal or an alkaline earth metal is dissolved in a polyamide resin, a polyetheresteramide resin, an aliphatic polyester, An antistatic composition obtained by adding to a polylactic acid resin, a thermoplastic elastomer and rubber has been proposed (see, for example, Patent Document 1).

  In addition, as a method for producing salt-modified electrostatic dissipative polymers made of polyurethane, a method is proposed in which lithium bis (fluoroalkylsulfonyl) imide is dissolved in a co-solvent and added. (See Patent Document 2).

International Publication WO 01/79354 A1 (Claims) US Pat. No. 6,140,405 (Claim 1, 14 and 15)

  However, depending on the type of metal salt added to the antistatic composition, the antistatic performance may not be sufficient. In addition, when metal salts such as perchloric acid are used, when the metal is packaged using a film or sheet made of this antistatic composition, there is a drawback that the metal surface is corroded, rusted or contaminated.

  Further, in the method described in Patent Document 2, an auxiliary solvent (ethylene carbonate, dimethyl sulfoxide, tetramethylene sulfone, N-methyl-2-pyrrolidone, etc.) for dissolving metal salts is used for the molded article of the antistatic composition. Bleeding or blooming on the surface contaminates the product. Further, the antistatic property is lowered by wiping the surface of the molded product, and the durability of the antistatic property is not sufficient. In particular, in a high temperature and high humidity atmosphere, bleeding and blooming are promoted, so that there is a problem that the antistatic property is remarkably lowered.

  The present invention has been made in view of the above problems, has excellent thermal stability, does not cause bleeding, blooming, and migration contamination, does not depend on humidity, has excellent rapidity, and causes deterioration in physical properties. It is an object of the present invention to provide a method for producing an antistatic pressure-sensitive adhesive composition that maintains excellent antistatic properties.

The present invention, in a composition comprising an adhesive resin, a process for the preparation of fluoro groups and salts with anions having a sulfonyl group is dispersed antistatic pressure-sensitive adhesive composition, both of polyethylene glycol A state in which a cation, which is a counter ion of the above anion, is coordinated to the ether oxygen atom of a polyether ester plasticizer having a polyether group in the main chain, the end of which is connected to an organic carboxylic acid by an ester bond. And a step of preparing the salt solution and a step of blending the kneading solution and the adhesive resin at a time and kneading to form a composition.

In the present specification, the polyether ester plasticizer includes a polyether group and an ester bond, and enters the gap between the resins to prevent the resin from being regularly oriented and maintain an amorphous state even below the glass transition point. Say. The polyether ester plasticizer preferably includes a polyether ester plasticizer having the following formula (1) or (2).
(In the formula, m and n are integers, and R represents an alkyl group.)

  This polyether ester plasticizer has low viscosity, good workability, low temperature flexibility, heat aging resistance, balance between flexibility and durability, non-volatility, non-migration, oil resistance Excellent safety (PL conformance).

  R is preferably an alkyl group having 1 to 14 carbon atoms. For example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, n-pentyl group, n-hexyl group, n-octyl group, isooctyl group, 2-ethylhexyl group, n-nonyl Group, isononyl group, n-decyl group, n-lauryl group and the like are preferable.

  M is preferably an integer of 2 or more.

  The polyether ester plasticizer containing a polyether group in the main chain preferably has a molecular weight of 250 to 2000, and more preferably 500 to 1500. The viscosity (25 ° C.) is preferably 30 to 600 mPa · s.

  According to this invention, the salt having an anion having a fluoro group and a sulfonyl group can be easily dissolved in the polyether ester plasticizer containing the polyether group in the main chain, and the concentration can be increased. By dispersing this solution, a salt having an anion having a fluoro group and a sulfonyl group can be incorporated into the adhesive resin in a large amount and uniformly. A solution of a polyether ester plasticizer in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved is compatible with the plasticity of the polyether ester plasticizer in the antistatic pressure-sensitive adhesive composition. Thus, plasticity is imparted while exhibiting antistatic properties. Moreover, since the polyether ester plasticizer containing a polyether group in the main chain can be brought close to the solubility parameter (SP value) of the adhesive resin, it has excellent affinity and does not bleed. As a result, an antistatic pressure-sensitive adhesive composition that does not cause migration contamination, does not depend on humidity, has excellent rapidity, and maintains excellent antistatic properties can be obtained.

  In this specification, “dispersion” means a state in which a solution of a polyether ester plasticizer in which the salt is dissolved is dispersed or dissolved in the form of fine droplets in a composition containing an adhesive resin. Say.

[Adhesive resin]
The adhesive resin is preferably an acrylic adhesive containing an acrylic copolymer.

[Acrylic copolymer]
The acrylic copolymer can be copolymerized by a solution polymerization method, a bulk polymerization method, a suspension polymerization method, an ultraviolet irradiation method, or an electron beam irradiation method.

  Among these, an acrylic copolymer containing a (meth) acrylic acid ester having an alkyl group having 1 to 14 carbon atoms as a monomer component is preferable. For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) Examples thereof include acrylate and n-lauryl (meth) acrylate, and can be used alone or in combination of two or more. Among them, n-butyl acrylate, 2-ethylhexyl acrylate, or a monomer using them in combination is preferably a main component, and the amount used is more preferably 50% by mass or more in the pressure-sensitive adhesive composition. It is particularly preferably 90% by mass or more. By using in this range, it is difficult for the plasticizer to bleed out, and when the antistatic pressure-sensitive adhesive composition is prepared, crosslinking is moderately performed. The adhesive residue can be suitably reduced.

  The acrylic copolymer is a monomer that gives a functional group, and a (meth) acrylic acid ester monomer or other vinyl monomer having a polar group such as a hydroxyl group, a carboxyl group, or an amino group in the side chain. It is preferable to contain. The content of the monomer having a polar group is preferably from 0.1 to 15% by mass, more preferably from 1 to 10% by mass, based on the monomer component constituting the acrylic copolymer. By containing in the said range, it is easy to adjust the cohesive force and adhesiveness of an adhesive to a suitable range.

  Examples of the monomer having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, hydroxypropyl (meth) acrylate, and caprolactone-modified (meth) acrylate. Hydroxyl group-containing (meth) acrylates such as polyethylene glycol mono (meth) acrylate and polypropylene glycol (meth) acrylate can be used, among which 2-hydroxyethyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxy It is preferred to use hexyl (meth) acrylate as a copolymerization component.

  As the monomer having a carboxyl group, acrylic acid, methacrylic acid, itaconic acid, maleic acid, crotonic acid, (meth) acrylic acid dimer, ethylene oxide-modified succinic acid acrylate, etc. can be used. It is preferable to use it as a copolymerization component.

  Examples of the monomer having a nitrogen atom include N-vinyl-2-pyrrolidone, N-vinylcaprolactam, acryloylmorpholine, acrylamide, N, N-dimethylacrylamide, and 2- (perhydrophthalimido-N-yl) ethyl acrylate. An amide group-containing vinyl monomer can be used, and among these, N-vinyl-2-pyrrolidone, N-vinylcaprolactam, and acryloylmorpholine are preferably used as the copolymerization component.

  Examples of vinyl monomers having other polar groups include vinyl acetate, acrylonitrile, maleic anhydride, itaconic anhydride and the like.

  The acrylic copolymer preferably has a weight average molecular weight in the range of 300,000 to 1,400,000. A weight average molecular weight can be measured using a gel permeation chromatography (GPC), and shows the weight average molecular weight converted into standard polystyrene (PS). When the weight average molecular weight is 300,000 or more, contamination of the adherend surface with a low molecular weight product tends to be difficult to occur. Furthermore, when the weight average molecular weight is suppressed to 1.4 million or less, there is an advantage that problems such as streaks during coating work due to an increase in the viscosity of the pressure-sensitive adhesive solution do not occur.

[Plasticizer]
In addition to the polyether ester plasticizer, an additional plasticizer may be added to the adhesive resin. As such a plasticizer, an ester formed from a mono- or dicarboxylic acid having a saturated or unsaturated acyclic hydrocarbon group and an alcohol having an acyclic hydrocarbon group having 1 to 20 carbon atoms, or A plasticizer comprising an ester in which the unsaturated group in the unsaturated acyclic hydrocarbon group is epoxidized is used. In the present invention, by using an ester having no cyclic skeleton as a plasticizer, the wettability of the pressure-sensitive adhesive layer to the adherend can be improved, and it is difficult to cause entrainment of bubbles at the time of attachment. Further, bleeding out of the plasticizer from the pressure-sensitive adhesive layer hardly occurs, and adherend contamination can be suitably reduced.

  As the saturated or unsaturated acyclic hydrocarbon group in the mono- or dicarboxylic acid component constituting the ester, an alkyl group or an alkylene group can be used, among which an alkyl group or alkylene group having 1 to 20 carbon atoms is preferable. It is more preferable that it is a C4-C18 alkyl group, and a C4-C14 alkyl group is especially preferable. The mono- or dicarboxylic acid having such a saturated or unsaturated acyclic hydrocarbon group has a carbon number close to that of the acrylic monomer constituting the acrylic copolymer used in the pressure-sensitive adhesive layer. Thus, compatibility with the antistatic pressure-sensitive adhesive composition is improved, and the plasticizer acrylic antistatic pressure-sensitive adhesive composition is suitably retained, so that bleeding out is suppressed.

  Examples of the monocarboxylic acid and dicarboxylic acid having a saturated or unsaturated acyclic hydrocarbon group include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacin. Mono- or polyester of linear aliphatic dicarboxylic acid such as acid, dodecanedioic acid, acetic acid, propionic acid, butyric acid, chitosulic acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, undecyl acid, lauric acid, tridecyl Acids, myristic acid, pentadecylic acid, palmitic acid, margaric acid, stearic acid, nonadecylic acid, arachidic acid, etc. Acid, eicosenoic acid, erucic acid, nervonic acid, linault Examples include unsaturated fatty acids such as acid, eicosadienoic acid, docosadienoic acid, linolenic acid, pinolenic acid, eleostearic acid, mead acid, stearidonic acid, arachidonic acid, eicosatetraenoic acid, adrenic acid, elaidic acid, docosahexaenoic acid, etc. It is done.

  As a C1-C20 acyclic hydrocarbon group in the alcohol which comprises ester, a C1-C20 alkyl group and an alkylene group, especially an alkyl group can be used conveniently, Especially, C4-C4 An 18 alkyl group is preferable, and an alkyl group having 4 to 14 carbon atoms is particularly preferable. Such an alcohol having a saturated or unsaturated acyclic hydrocarbon group has a carbon number close to that of the acrylic monomer constituting the acrylic copolymer used in the pressure-sensitive adhesive layer. Since the compatibility with the electric pressure-sensitive adhesive composition is improved and it is suitably held in the plasticizer acrylic antistatic pressure-sensitive adhesive composition, bleeding out is suppressed. In the present invention, as compared with the carboxylic acid component constituting the ester, the number of carbon atoms of the hydrocarbon group of the alcohol component is the carbon of the acrylic monomer constituting the acrylic copolymer used in the pressure-sensitive adhesive layer. By setting the number of carbons to be close to the number, it is particularly easy to suppress adherend contamination.

  Examples of the alcohol having such an acyclic hydrocarbon group include methyl alcohol, ethyl alcohol, propanol, butanol, pentanol, hexanol, heptanol, octyl alcohol, nonyl alcohol, decyl alcohol, undecyl alcohol, dodecyl alcohol, Examples include tridecyl alcohol, tetradecyl alcohol, pentadecyl alcohol, cetyl alcohol, heptadecyl alcohol, octadecyl alcohol, nonadecyl alcohol, and straight chain or branched alcohol of aralkyl alcohol. Of these, butanol, pentanol, hexanol, heptanol, octyl alcohol, nonyl alcohol, and decyl alcohol can be particularly preferably used.

  More preferably, an ester formed from the above mono- or dicarboxylic acid and an alcohol is used as a plasticizer. The ester may have a skeleton composed of a saturated or unsaturated hydrocarbon group, but is preferably an ester not having a skeleton composed of an unsaturated hydrocarbon group. Moreover, an epoxidized ester in which an unsaturated bond of an ester having a skeleton composed of the unsaturated hydrocarbon group is epoxidized can also be preferably used. Among the esters, adipic acid monoester, sebacic acid monoester, and epoxidized fatty acid monoester can be particularly preferably used.

  The ester used as the plasticizer may be either a monoester or a polyester, but it is easy to control the SP value within a suitable range and easily improve the compatibility with the pressure-sensitive adhesive. The ester having a weight average molecular weight of 1000 or less is preferable, and an ester having a weight average molecular weight of 300 to 800 is particularly preferable.

  It is preferable to use a plasticizer having a solubility parameter (SP value) of 8.5 or less as the plasticizer. Especially, it is preferable that it is 7.0-8.4. If the SP value of the plasticizer is 8.5 or less, it is excellent in compatibility with the acrylic pressure-sensitive adhesive copolymer. Therefore, the plasticizer is left for a long time in a high-temperature and high-humidity environment with a pressure-sensitive adhesive film applied to the surface to be adhered. In this case, the surface of the deposition target is less likely to be clouded when peeled off from the surface of the deposition target. As the SP value of the plasticizer, a plasticizer having a value larger than 7.0 is generally used. The SP value is a value calculated by the small formula [P.A.J.Small: J.Appl.Chem., 3, 71 (1953)] proposed by J. Small.

  The plasticizer is preferably added in an amount of 0.5 to 30 parts by weight with respect to 100 parts by weight of the (meth) acrylic copolymer constituting the acrylic pressure-sensitive adhesive. It is more preferable to add below, and it is especially preferable to add 1 to 10 parts by weight. When the added amount of the plasticizer is more than 0.5 parts by weight, the bubbles are easily removed when manually pasted. Further, when the amount is less than 30 parts by weight, the display surface is less likely to fog up even in a high temperature and high humidity environment.

[Crosslinking agent]
In order to increase the cohesive strength of the pressure-sensitive adhesive layer, it is preferable to add a crosslinking agent to the acrylic antistatic pressure-sensitive adhesive composition. Examples of the crosslinking agent include an isocyanate crosslinking agent, an epoxy crosslinking agent, a chelate crosslinking agent, and an aziridine crosslinking agent. Among these, when an isocyanate crosslinking agent is used, it is preferable to use it because it is easy to improve the air bleeding property of the obtained film.

  The addition amount of the crosslinking agent is preferably adjusted so that the gel fraction of the pressure-sensitive adhesive layer is 80 to 99%. A more preferable gel fraction is 90 to 99%. By setting it as the range of the said gel fraction, the ratio of a low molecular weight component decreases, it becomes easy to prevent easy drop-off of an adhesive layer, and it can reduce especially adhesive residue suitably. In addition, a gel fraction immerses the adhesive layer composition after curing in toluene, measures the mass after drying of the insoluble part which remained after leaving for 24 hours, and represents it as a percentage with respect to the original mass.

[Salt with anion having a fluoro group and a sulfonyl group]
The salt having an anion having a fluoro group and a sulfonyl group is a salt comprising an anion having an alkali metal, a group 2A element, a transition metal or an amphoteric metal, and the anion having the fluoro group and the sulfonyl group. Is preferred.

  The salt having an anion having a fluoro group and a sulfonyl group is particularly preferably an alkali metal salt of bis (trifluoromethanesulfonyl) imide or an alkali metal salt of trifluoromethanesulfonate ion. Lithium salts are particularly preferred.

  The salt having an anion having a fluoro group and a sulfonyl group is in a proportion of 0.1 to 200 parts by mass with respect to 100 parts by mass of the polyether ester plasticizer. It is preferably dissolved in the agent.

  It is preferable that the salt provided with the anion which has the said fluoro group and a sulfonyl group with respect to 100 mass parts of said adhesive resins is contained 0.01 mass part or more and 30 mass parts or less.

  The reason for this regulation is that the antistatic property is not sufficiently exhibited when the amount of the salt having the anion is less than 0.01 parts by mass. On the other hand, if the amount of the salt having an anion exceeds 30 parts by mass, the antistatic effect is saturated, resulting in a problem of high cost.

[Polymer type antistatic agent]
The antistatic pressure-sensitive adhesive composition may further contain a polymer-type antistatic agent. It has been found that the inclusion of a polymer-type antistatic agent in the antistatic pressure-sensitive adhesive composition of the present invention can stabilize the salt having the anion. Further, since the salt having an anion is dispersed in a polyether ester plasticizer containing a polyether group in the main chain, the salt is a polyether containing a polyether group in the main chain. It is considered that the polymer type antistatic agent having an affinity for the ester plasticizer gathers and is stabilized by the affinity of both. Examples of such polymer-type antistatic agents include polyether block polyolefin copolymers, polyoxyalkylene copolymers, and ethylene oxide-propylene oxide-allyl glycidyl copolymers.

  What is necessary is just to contain the said polymer type antistatic agent in the ratio of 0.1 to 65 mass parts with respect to 100 mass parts of said adhesive resins.

  The reason for this regulation is that the antistatic property is not sufficiently exhibited when the blending amount of the polymer type antistatic agent is less than 0.1 parts by mass. On the other hand, when the blending amount of the polymer type antistatic agent exceeds 65 parts by mass, the antistatic effect is saturated, resulting in a problem of high cost. Moreover, it is because the physical property of a composition may be lost.

  According to the method of the present invention, it has been found that a salt with an anion having a fluoro group and a sulfonyl group has a uniform affinity in the adhesive resin. An antistatic pressure-sensitive adhesive composition that does not cause bleeding, blooming, and migration contamination, does not depend on humidity, has excellent rapidity, does not cause deterioration in physical properties, and maintains excellent antistatic properties was obtained. .

  The antistatic pressure-sensitive adhesive composition of the present invention further includes an antioxidant, a heat stabilizer, an ultraviolet absorber, a flame retardant, a flame retardant aid, a colorant, a pigment, an antibacterial / antifungal agent, a light fastener, and a plasticizer. Known additives such as tackifiers, dispersants, antifoaming agents, curing catalysts, curing agents, leveling agents, water repellents, coupling agents, fillers, vulcanizing agents, chelating agents, and vulcanization accelerators. It can be added as necessary.

A production method according to another aspect of the present invention is a method for producing an antistatic pressure-sensitive adhesive composition in which a salt having an anion having a fluoro group and a sulfonyl group is dispersed in a composition containing an adhesive resin. The both ends of polyethylene glycol are connected to an organic carboxylic acid by an ester bond, and the ether oxygen atom of a polyether ester plasticizer containing a polyether group in the main chain is a counter ion of the anion. A step of preparing a salt solution in which cations are coordinated, a step of kneading the salt solution (first component) and an adhesive resin (second component) to form a composition, and the composition And kneading or blending the product with an adhesive resin (second component).

  By the kneading of the first component and the second component, the salt solution is dispersed or dissolved in the composition in the form of fine droplets. In addition, the salt is further kneaded or blended with the adhesive resin (second component) in a state where the salt is dissolved in the composition, so that the salt is dispersed in a state more evenly compatible with the adhesive resin (second component). Is done.

  The antistatic pressure-sensitive adhesive composition obtained by the present invention can be used as a pressure-sensitive adhesive layer of a protective pressure-sensitive adhesive film, a polarizing film or a retardation film having a substrate and a pressure-sensitive adhesive layer.

  In addition, the protective adhesive film, polarizing film or retardation film is used for optical members such as various displays and polarizing plates, and has excellent transparency, almost no coloring, excellent removability, and peeling at the time of peeling. Little charge.

  The substrate is not particularly limited as long as it is a substrate generally used for an adhesive film, and any of a biaxially stretched film, a uniaxially stretched film, and an unstretched film can be used. For such a plastic film, a polyolefin-based resin film is preferably used. For example, a resin such as a low-density polyethylene resin, a linear low-density polyethylene resin, a high-density polyethylene resin, a polypropylene resin, or an ethylene-propylene copolymer resin. A film etc. are mentioned. More specifically, polyethylene terephthalate (PET), polybutylene terephthalate, polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, diacetyl cellulose film, triacetyl cellulose film, acetyl cellulose butyrate film, polyvinyl chloride film, polyvinyl chloride Vinylidene film, polyvinyl alcohol film, ethylene-vinyl acetate copolymer film, polystyrene film, polycarbonate film, polymethylpentene film, polysulfone film, polyetheretherketone film, polyethersulfone film, polyetherimide film, polyimide film, fluorine Resin film, nylon film, acrylic resin film, etc. Door can be. Of these, resin films such as linear low-density polyethylene resin and ethylene-propylene copolymer resin, which are excellent in transparency, are more preferable, and among them, PET film has good handling without using additives such as slip agents. Therefore, the possibility of contamination of the adherend surface due to the additive can be reduced, and since it has high transparency, there is an advantage that it can be inspected with the adhesive film attached, so that it can be particularly preferably used. Furthermore, because of its high tensile strength and low waist, it is difficult for air bubble entrainment to occur when a part of the adhesive film other than the application part comes into contact with the adherend during application, and it is a biaxially stretched PET that excels in handling during processing. A film is more preferable.

  Although it does not specifically limit as thickness of the said base material, 10-150 micrometers is preferable, 25-100 micrometers is still more preferable, 38-100 micrometers is especially preferable. If it is thicker than 10 μm, the film strength is durable enough to obtain a protective performance, so that problems such as tearing of the film at the time of peeling hardly occur, and if it is 25 μm or more, flexibility suitable for manual attachment can be obtained. On the other hand, if the thickness is less than 150 μm, the problem of peeling due to catching of the edge portion hardly occurs, and if it is 100 μm or less, the light transmittance of the film is good, and the problem that the film itself becomes expensive does not occur.

  The elastic modulus of the substrate is preferably 1 to 7 GPa. If the elastic modulus is 1 GPa or more, deformation of the film base material hardly occurs when the adhesive film is formed, and if it is 7 GPa or less, the film base material can follow even when the adhesive film is attached to a gently curved surface. Of hardness.

  When printing is performed for the purpose of providing a display function such as POP on the surface of the substrate described above, an anchor coat layer can be provided in order to improve ink adhesion.

  A hard coat layer can be provided on the surface of the substrate described above for the purpose of preventing scratches on the surface.

  The production method according to the present invention provides an antistatic pressure-sensitive adhesive composition in which a salt containing an anion having a fluoro group and a sulfonyl group is dispersed in a composition containing an adhesive resin. The salt having an anion having a fluoro group and a sulfonyl group is dispersed in a state dissolved in a polyether ester plasticizer containing a polyether group in the main chain. A salt having an anion having a fluoro group and a sulfonyl group has a uniform affinity in the composition containing an adhesive resin via the polyether ester plasticizer. Salts with anions having a fluoro group and a sulfonyl group have high electrical conductivity, high heat resistance, and nonflammability, so they have excellent antistatic and thermal stability, do not corrode metals, and can be used in environments such as humidity. An antistatic adhesive composition that does not depend can be obtained.

It is a figure explaining the effect of this invention.

  Anti-static adhesive with excellent thermal stability, no bleeding, blooming and migration contamination, no dependence on humidity, high-efficiency, no deterioration in physical properties, and excellent anti-static properties A composition containing an adhesive resin by dissolving a salt having an anion having a fluoro group and a sulfonyl group in a polyether ester plasticizer containing a polyether group in the main chain, for the purpose of obtaining an agent composition This was realized by dispersing in the material.

  As the salt, bis (trifluoromethanesulfonyl) imide lithium is used and dissolved in a polyether ester plasticizer composed of diethylene glycol and adipic acid, as shown in FIG. Ions are coordinated. When the adhesive layer is formed, an adhesive layer in which lithium ions are uniformly dispersed is formed in a state where lithium ions are coordinated to ether oxygen atoms. In the adhesive layer, lithium ions are easily moved by the molecular motion of ether oxygen. When an electric field is applied to this from the outside, lithium ions move (ion transport) toward the corresponding poles in the adhesive layer to develop ionic conductivity.

  In addition, a polyether ester plasticizer obtained by polymerizing diethylene glycol and adipic acid, which is a medium in which a salt having an anion having a fluoro group and a sulfonyl group is dissolved, has an adhesive resin due to its plastic expression. It gives further tackiness.

  In the production method of the antistatic pressure-sensitive adhesive composition of the present invention, first, a salt provided with an anion having a fluoro group and a sulfonyl group in a polyether ester plasticizer containing a polyether group in the main chain. Prepare a salt solution to be dissolved. The polyether ester plasticizer containing a polyether group in the main chain quickly dissolves a salt having an anion having a fluoro group and a sulfonyl group while generating heat. The salt solution and the adhesive resin are blended and kneaded to form an antistatic adhesive composition. In order to produce the antistatic pressure-sensitive adhesive composition, predetermined amounts of both components may be mixed using a known method. For example, dry blending can be performed with a Henschel mixer, a ribbon blender, a super mixer, a tumbler, or the like. Further, melt mixing may be performed with a single or twin screw extruder, a Banbury mixer, a plast mill, a kneader, a roll, or the like. As needed, it can also carry out in inert gas atmosphere, such as nitrogen.

  Examples will be described below.

[Acrylic copolymer A]
Polymerization started with 10 parts of n-butyl acrylate, 88 parts of 2-ethylhexyl acrylate, 2 parts of 4-hydroxybutyl acrylate and 0.1 part of acrylic acid in a reaction vessel equipped with a condenser, a stirrer, a thermometer and a dropping funnel As an agent, 0.2 part of 2,2′-azobisisobutylnitrile is dissolved in 100 parts of ethyl acetate, substituted with nitrogen, polymerized at 80 ° C. for 2 hours, and an acrylic copolymer A having a polymerization average molecular weight of 600,000 is obtained. Solution was obtained. The calculated Tg of the acrylic copolymer A is -68.
° C. Ethyl acetate was added to the solution and mixed uniformly to obtain a pressure-sensitive adhesive main agent having a solid content of 40%.

[Acrylic adhesive composition A]
In the above-mentioned adhesive main agent, 100 parts of acrylic copolymer A, polyether ester plasticizer (Monocizer (registered trademark) W-262, molecular weight 556, viscosity 30 mPa · s, 25 ° C., manufactured by DIC Corporation, formula 10 parts of a composition solution (Sanconol (registered trademark) AD-2600-50R, manufactured by Sanko Chemical Co., Ltd.) in which 50 parts by mass of bis (trifluoromethanesulfonyl) imide lithium is dissolved in (having the structural formula shown in (2)) , 1.5 parts of isocyanate crosslinking agent (Coronate (registered trademark) HX, manufactured by Nippon Polyurethane Industry Co., Ltd.) and 1.0 part of chelating crosslinking agent (curing agent M-5A, manufactured by Soken Chemical Co., Ltd.) And stirred for 15 minutes to obtain an acrylic pressure-sensitive adhesive composition.

[Protective film]
When the above-mentioned acrylic pressure-sensitive adhesive composition A is dried on a 50 μm-thick biaxially stretched polyester film separator (SP-PET-01-BU, manufactured by Tosero) with a silicone release agent applied, the thickness when dried becomes 20 μm. And then dried. Further, a transparent biaxially stretched polyester film (T100G, manufactured by Mitsubishi Plastics Co., Ltd.) having a thickness of 50 μm was bonded to the pressure-sensitive adhesive surface to prepare a protective film having excellent transparency. The surface resistivity of the protective film was measured and found to be 4 × 10 ⁸ Ω / sq. This film was allowed to stand for 1 week under the conditions of 70% humidity and 80 ° C., and the surface resistivity was measured. As a result, it was 5 × 10 ⁸ Ω / sq. Moreover, the peeling voltage (peeling angle 150 °, peeling speed 10 m / min, using KSD-0103 manufactured by Kasuga Denki Co., Ltd.) of this protective film was measured (23 ° C., 500% RH). It was 0.0 kv.

  This protective adhesive film was aged for 2 days in an environment of 40 ° C. and 60% RH, and then the adhesive strength (width 25 mm × length 80 mm, peeling speed 300 mm / min, direction 180 °) was measured. The adhesive force was 0.03 N / 25 mm. In addition, after affixing to a PMMA plate having a width of 25 mm and a length of 80 mm by the application method specified in JIS Z0237 (2000), the sample was left for 2 weeks under wet heat conditions (0 ° C., 90% RH), and then a peel test was performed. It was. The peel strength was 0.02 N / 25 mm.

[Acrylic adhesive composition B]
Monocizer (registered trademark) W-262 shown in Formula (2) and Polycizer shown in Formula (1) as a polyetherester plasticizer with respect to 100 parts of acrylic copolymer A as the adhesive main agent of Example 1 A composition obtained by dissolving 20 parts by mass of bis (trifluoromethanesulfonyl) imidolithium in a 1: 1 mixture with W-230-H (molecular weight: about 1000, viscosity: 220 mPa · s, 25 ° C., manufactured by DIC) (Sanconol (registered) Trademark) AD-2623-20R (manufactured by Sanko Chemical Co., Ltd.) 15 parts and 0.6 part by mass of tolylene diisocyanate adduct of isocyanate trimethylolpropane were added and stirred for 15 minutes. Acrylic pressure-sensitive adhesive composition B was obtained in the same manner as above.

[Adhesive sheet]
The prepared acrylic pressure-sensitive adhesive composition B was coated on a release paper and dried, and then a pressure-sensitive adhesive sheet having a uniform pressure-sensitive adhesive layer having a thickness of 15 μm was obtained. The pressure-sensitive adhesive layer was pressure-bonded to an iodine-type polarizing plate having a film thickness of 185 μm. As a result of measuring the surface resistivity of the adhesive layer, it was 8 × 10 ⁸ Ω / sq. Moreover, as a result of measuring the peeling voltage of the adhesive sheet (peeling angle 150 °, peeling speed 10 m / min, using KSD-0103 manufactured by Kasuga Denki Co., Ltd.), 0.0 kv, 180 °, and peel adhesive strength is 3.2 N. / 25 mm.

5 parts of a composition obtained by dissolving 70 parts by mass of lithium trifluoromethanesulfonate in a polyether ester plasticizer (Monocizer (registered trademark) W-262) with respect to 100 parts of the acrylic copolymer A of Example 1 Except for blending, an acrylic pressure-sensitive adhesive composition was prepared in the same manner as in Example 1, and then a protective pressure-sensitive adhesive film was obtained. The surface resistivity of the protective film was 2 × 10 ¹⁰ Ω / sq. Moreover, the peeling voltage of this protective film was 0.0 kv.

Polyether ester compound (1: 1 mixture of Monosizer (registered trademark) W-262 and Polysizer (registered trademark) W-230-H) with respect to 100 parts of acrylic copolymer A of Example 1, An acrylic pressure-sensitive adhesive composition was prepared in the same manner as in Example 2, except that 10 parts of a composition in which 20 parts by mass of bis (trifluoromethanesulfonyl) imide lithium was dissolved was blended. Subsequently, after coating on release paper and drying, an adhesive sheet having a thickness of 10 μm was obtained. The pressure-sensitive adhesive layer was first subjected to pressure-sensitive adhesive processing on an iodine-type polarizing plate, and then sandwiched between two triacetyl cellulose (TAC) films and bonded. The volume resistivity of this three-layer film was 1 × 10 ¹⁰ Ω · cm.

  In the above embodiment, polyethylene glycol is exemplified as the polyether group. However, the present invention is not limited to this, and even if polypropylene glycol is used, a considerable effect can be obtained.

In addition to the above-described salts having an anion having a fluoro group and a sulfonyl group used in the present invention, for example, lithium bis (fluorosulfonyl) imide, LiN (C ₂ F ₅ SO ₂ ) ₂ , _{LiN (C 4 F 9 SO 2} ) (CF 3 SO 2), LiN (C 8 F 17 SO 2) (CF 3 SO 2), LiN (CF 3 CH 2 OSO 2) 2, LiN (CF 3 CF 2 CH ₂ OSO ₂ ) ₂ , LiN (HCF ₂ CF ₂ CH ₂ OSO ₂ ) ₂ , LiN ((CF ₃ ) ₂ CHOSO ₂ ) ₂ , tris (fluoroalkylsulfonyl) methidolithium Li (CF ₃ SO ₂ ) ₃ C, etc. are also used. it can.

  The antistatic pressure-sensitive adhesive composition obtained by the present invention includes a protective adhesive film having a base material and an adhesive layer, a bonding between a polarizing filter and a retardation film, and a bonding between a polarizing film and a surface protective plate. , And can be used for laminating a retardation film and a liquid crystal cell (parts in which liquid crystal is enclosed between substrates). In addition, a polarizing film subjected to adhesive processing using the antistatic adhesive composition according to the present invention is a portable word processor, a display of a personal computer, a display panel of an automobile, a display part of a wristwatch or a calculator, and further a portable television. Can be used for many liquid crystal displays.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  According to the present invention, it has excellent thermal stability, bleeding, blooming and migration contamination do not occur, it does not depend on humidity, it has excellent fast-acting properties, does not cause deterioration of physical properties, and has excellent antistatic properties. A sustained antistatic adhesive composition is obtained. It can be used for adhesive processing with antistatic properties such as protective films, polarizing films and retardation films.

Claims (3)

A method for producing an antistatic pressure-sensitive adhesive composition in which a salt having an anion having a fluoro group and a sulfonyl group is dispersed in a composition containing an adhesive resin,
A cation, which is a counter ion of the anion, is present on the ether oxygen atom of a polyether ester plasticizer containing a polyether group in the main chain, in which both ends of polyethylene glycol are connected to an organic carboxylic acid by an ester bond. Preparing a salt solution in a coordinated state;
The manufacturing method of the antistatic adhesive composition provided with the process of mix | blending the said salt solution and the said adhesive resin at once, knead | mixing, and forming a composition. The method for producing an antistatic pressure-sensitive adhesive composition according to claim 1, wherein the polyether ester plasticizer has a chemical formula represented by the following formula (1) or (2).
(In the formula, m and n are integers, and R represents an alkyl group.) A method for producing an antistatic pressure-sensitive adhesive composition in which a salt having an anion having a fluoro group and a sulfonyl group is dispersed in a composition containing an adhesive resin,
A cation, which is a counter ion of the anion, is present on the ether oxygen atom of a polyether ester plasticizer containing a polyether group in the main chain, in which both ends of polyethylene glycol are connected to an organic carboxylic acid by an ester bond. Preparing a salt solution in a coordinated state;
Kneading the salt solution (first component) and the adhesive resin (second component) to form a composition;
A method for producing an antistatic pressure-sensitive adhesive composition, comprising the step of kneading or blending the composition with a pressure-sensitive adhesive resin (second component).