Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
  • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
  • C08F20/04—Acids, Metal salts or ammonium salts thereof
  • C08F20/06—Acrylic acid; Methacrylic acid; Metal salts or ammonium salts thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F6/00—Post-polymerisation treatments
  • C08F6/06—Treatment of polymer solutions
  • C08F6/10—Removal of volatile materials, e.g. solvents
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers

Definitions

• the present invention relates to a method for producing a resin composition and a pressure-sensitive adhesive containing the resin composition.
• solvent-based adhesives which are made by further dissolving the adhesive resin composition in a liquid to make it easier to apply, are widely used.
• adhesive resin compositions generally only dissolve in organic solvents
• solvent-based adhesives that use organic solvents have flash points and are often considered hazardous materials under the Fire Service Act.
• Such solvent-based adhesives are subject to various restrictions, such as restrictions on storage location and quantity, and use in explosion-proof facilities.
• odor it can be reduced by increasing the molecular weight of the compound having a polymerizable unsaturated bond (hereinafter referred to as the polymerizable compound, for example, a (meth)acrylic monomer), thereby decreasing the vapor pressure of the remaining polymerizable compound.
• the polymerizable compound for example, a (meth)acrylic monomer
• increasing the molecular weight of the polymerizable compound reduces its polarity (SP value), resulting in poor solubility.
• SP value polarity
• the types of organic solvents that can be selected are limited to those with low polarity.
• Another issue is that increasing the molecular weight of the polymerizable compound raises the glass transition point of the polymer, resulting in poor adhesion as an adhesive.
• Patent Document 1 One known method for reducing the amount of polymerizable compounds remaining in the final resin composition is to add a scavenger to the resin composition (see Patent Documents 1 and 2).
• adding a scavenger takes advantage of the low copolymerizability between the remaining (meth)acrylic monomer and the scavenger, promoting the polymerization reaction between the remaining (meth)acrylic monomers themselves relatively more than the polymerization reaction between the remaining (meth)acrylic monomer and the scavenger, thereby reducing the amount of remaining (meth)acrylic monomer.
• a polyfunctional (meth)acrylic monomer having multiple (meth)acryloyl groups per molecule is used as a scavenger. This scavenger is highly reactive, and reduces the amount of remaining (meth)acrylic monomer through the reaction between the remaining (meth)acrylic monomer and the scavenger.
• Patent Document 1 a monofunctional vinyl ether compound is used as a scavenger, and the final amount of remaining (meth)acrylic monomer is approximately 0.3 to 0.7 parts by mass per 100 parts by mass of the resin composition. However, this remaining amount is not considered to be a sufficient reduction. However, adding more scavenger may be able to further reduce the amount of remaining (meth)acrylic monomer, but since even more of the added scavenger remains unreacted, the odor from the scavenger then becomes a problem. In other words, because the scavenger itself is treated in the same way as the remaining monomer, it is difficult to substantially reduce the total amount of remaining monomer. Furthermore, if the remaining unreacted scavenger is used as an adhesive, it will migrate to the interface with the adherend, causing a decrease in adhesive strength.
• the scavenger has multiple (meth)acryloyl groups, the scavenger promotes cross-linking between resins, which can cause the resin to polymerize beyond the target molecular weight, resulting in increased viscosity or gelation of the resin composition. Because of this, it is not possible to add a sufficient amount of scavenger, making it difficult to both sufficiently reduce the amount of residual (meth)acrylic monomer and achieve the target molecular weight.
• scavengers is a promising method for reducing the amount of residual polymerizable compounds (e.g., (meth)acrylic monomers), but there is still room for improvement in its effectiveness, and further technological development is desired.
• residual polymerizable compounds e.g., (meth)acrylic monomers
• water-emulsion adhesives which use water as a solvent.
• these water-emulsion adhesives are inferior to organic solvent-based adhesives in terms of weather resistance and water resistance.
• water-emulsion adhesives have problems such as deterioration (rotting) of the aqueous solution depending on the storage environment, and separation due to freezing. Adding preservatives to address this reduces the adhesive's functionality.
• water has a high latent heat of evaporation, which slows down the drying speed, reducing the adhesive's usability.
• Patent Document 3 uses the hydrofluoroether (HFE) HFE-347 as the main component of a fluorine solvent used to eliminate the flash point, but compared to organic solvents, this has poor compatibility with resin compositions whose main component is a polymer of a (meth)acrylic monomer.
• HFE hydrofluoroether
• Patent Document 3 mixes in hexamethyldisiloxane, but if the ratio of HFE solution in the solution is increased to reduce flammability, the adhesive component, which is a resin composition, separates, which is a problem. For this reason, HFE cannot be used as the main component of the solvent.
• HFEs Apart from HFEs, there are many fluorine solvents that are non-flammable or have high flash points and good solubility. However, generally, solvents that are highly soluble in resin compositions whose main component is a polymer of (meth)acrylic monomer also have high solubility in amorphous resins, and so if the substrate to which they are applied is made of a similar resin material, there is a risk that they may corrode or dissolve the substrate. As a result, selecting a fluorine solvent other than HFE limits its applications.
• Patent Document 4 introduces a technology that provides a non-flammable surface treatment agent by combining a solution of HFE and a lower alcohol component with a fluorine-containing polymer (fluorine-containing resin composition).
• fluorine-containing polymers fluorine-containing resin compositions
• these polymers are more difficult to manufacture, resulting in higher manufacturing costs and naturally limiting their uses.
• Patent Document 5 describes a method for reducing residual monomers by introducing hydrogen gas into a polymer solution in the presence of a hydrogenation catalyst such as palladium-supported carbon.
• a hydrogenation catalyst such as palladium-supported carbon.
• hydrogen gas is highly flammable and explosive, making it extremely dangerous in mass production processes.
• the hydrogenation catalyst is a powder in which a precious metal is supported on carbon, which poses the problem of having to be removed after the polymerization reaction using a tedious method such as diluting it with a solvent to reduce viscosity and then filtering it.
• the present invention was made in consideration of at least some of the problems pointed out above, and aims to provide a manufacturing technology that further reduces the amount of residual monomer during polymerization using a compound having a polymerizable unsaturated bond (e.g., a (meth)acrylic monomer) as a raw material, as well as a resin composition obtained thereby.
• a compound having a polymerizable unsaturated bond e.g., a (meth)acrylic monomer
• the present invention which achieves the above-mentioned objective, is a method for producing a resin composition, comprising: a polymerization step in which a compound having a polymerizable unsaturated bond is included as a raw material and the compound is polymerized to produce a polymerized composition; and a reducing agent addition step in which a reducing agent is added when the conversion rate of the compound in the polymerization step is 90% or higher and/or when the polymerization reaction of the compound has been completed, thereby reducing the remaining unpolymerized compound to another compound.
• the reducing agent may be a silicon-hydrogen bond-containing compound.
• the polymerization step may be characterized by using a (meth)acrylic monomer as the compound.
• the (meth)acrylic monomer may be one or more (meth)acrylate monomers having an ester moiety with 1 to 8 carbon atoms.
• the amount of the remaining (meth)acrylic monomer may be reduced to 0.2% by weight or less in the reducing agent addition step.
• the method for producing the resin composition may also include a dissolution step in which the polymer composition obtained through the reducing agent addition step is dissolved in a fluorine-based solvent selected from at least one of hydrofluoroether, hydrofluoroolefin, and hydrofluorocarbon.
• a reduction reaction catalyst may be added.
• the polymer composition may be characterized by having a crosslinkable moiety.
• the present invention which achieves the above-mentioned objective, is a pressure-sensitive adhesive characterized by having as its main component the resin composition produced by the above-mentioned manufacturing method.
• 1 is a table showing raw materials and verification results of examples and comparative examples of resin compositions produced by the first production method of the present embodiment.
• 1A is a gas chromatograph chart of a resin composition produced by the second production method of the present embodiment, and FIG. 1B is a partially enlarged chart of FIG. 1A.
• 1A is a gas chromatograph chart of a resin composition produced by a third production method of the present embodiment, and FIG. 1B is a partially enlarged chart of FIG. 1A.
• a reducing agent is used as a scavenger added in the latter half of the polymerization process or after the polymerization process.
• polymerizable compounds compounds having polymerizable unsaturated bonds
• a resin composition can be obtained in which the adverse effects of remaining polymerizable compounds are reduced.
• (meth)acrylic monomers for example. This reduces the amount of residual (meth)acrylic monomer to 0.2% by weight or less per 100 parts by weight of the initial input. As a result, a resin composition can be obtained in which the adverse effects of residual (meth)acrylic monomers are reduced. It is also possible to obtain a resin composition that is almost free of the odor originating from the (meth)acrylic monomer. In this case, it is preferable to use a silicon-hydrogen bond-containing compound as the reducing agent, which itself has a relatively low odor. With silicon-hydrogen bond-containing compounds, hydrogen abstraction reactions do not occur, so crosslinking between resins or polymerization does not proceed, and there is little risk of the resin composition thickening or gelling.
• the (meth)acrylic monomer is a (meth)acrylate monomer in which the number of carbon atoms in the ester moiety is limited to approximately 1 to 8, thereby increasing solubility in a solvent primarily containing HFE.
• This (meth)acrylate monomer is generally considered difficult to reduce in residual amounts during the polymerization process, and its low molecular weight results in a strong odor, making it difficult to use in practical applications.
• a reducing agent e.g., a silicon-hydrogen bond-containing compound
• resin compositions and adhesive solutions that are both odor-reducing and non-flammable.
• the (meth)acrylic monomer used as a raw material for the polymerization reaction be the main component (50% by weight or more) of the raw materials for the polymerization reaction. Furthermore, it is preferable that the (meth)acrylate monomer with a carbon number limited to approximately 1 to 8 be the main component (50% by weight or more) of the raw materials for the polymerization reaction, and even more preferably, it is the main component (50% by weight or more) of the (meth)acrylic monomer in the raw materials.
• the reducing agent used as a scavenger is, for example, a silicon-hydrogen bond-containing compound that contains one or more silicon-hydrogen bonds. While the detailed reaction mechanism of the reducing agent (silicon-hydrogen bond-containing compound) used as a scavenger is unknown, it is presumed that electrons are donated to unreacted monomers, i.e., remaining polymerizable compounds (e.g., (meth)acrylic monomers), resulting in addition reduction, and the resulting change in the compound structure results in a change in properties.
• silicon-hydrogen bond-containing compounds may have multiple silicon-hydrogen bonds. Even if silicon-hydrogen bond-containing compounds have multiple silicon-hydrogen sites within their molecules, no crosslinking reactions have been observed, and no thickening or gelation has been observed.
• a reduction reaction occurs, producing a structure in which a proton (e.g., a proton of a silicon-hydrogen compound) in the reducing agent is added to the double bond site of the remaining polymerizable compound (e.g., a (meth)acrylic monomer, more specifically, a (meth)acrylate monomer), changing the polymerizable compound into a different substance (no longer a monomer).
• a proton e.g., a proton of a silicon-hydrogen compound
• the remaining polymerizable compound e.g., a (meth)acrylic monomer, more specifically, a (meth)acrylate monomer
• an addition reaction caused by the reducing agent may also occur.
• the resin composition produced in this embodiment may contain substances resulting from the reduction of the polymerizable compound or substances resulting from the addition of a reducing agent to the polymerizable compound.
• a reducing agent for example, when a (meth)acrylic monomer is used, propionic acid derivatives or (2-methyl)propionic acid derivatives resulting from the reduction of the (meth)acrylic monomer, or compounds resulting from the addition of a silicon-hydrogen bond-containing compound to the (meth)acrylic monomer, may remain.
• a reducing agent is added to a polymerization solution containing remaining vinyl compounds, ethyl acetate is produced as a reduction product.
• the reducing agent is added as a scavenger for residual monomers, so some (excess) of the added reducing agent will remain in the final composition.
• reaction conditions such as the type of reducing agent (especially a silicon-hydrogen bond-containing compound) used as a scavenger, the addition of multiple types, the amount added, the reaction temperature, and the timing of addition, it is possible to reduce the amount of residual (meth)acrylic monomer. According to experiments and verification by the inventors, it is possible to ultimately reduce the amount of residual (meth)acrylic monomer to 0.2% by weight or less.
• a common method can be selected as the polymerization reaction technique for the polymerizable compound (e.g., (meth)acrylic monomer).
• the polymerizable compound e.g., (meth)acrylic monomer
• the initiator in this case is preferably an organic peroxide or an azo compound.
• the resin composition obtained in this embodiment When the resin composition obtained in this embodiment is used as an adhesive, it similarly becomes a highly practical adhesive that has little odor, excellent adhesion, and is soluble in fluorine solvents.
• the resin composition obtained in this embodiment is soluble in fluorine-based solvents, particularly HFE.
• fluorine-based solvents particularly HFE.
• a non-flammable solution-type resin composition can be provided. It is desirable to select one or more fluorine-based solvents from the group consisting of hydrofluoroethers, hydrofluoroolefins, and hydrofluorocarbons, each of which has a boiling point of less than 80°C.
• the resin composition of this embodiment can be used as a surface treatment agent for forming adhesive layers, as well as in general adhesive processed products such as transdermal preparations, bandages, adhesive tapes, adhesive sheets, double-sided tapes, and labels; fine dust capture agents; adhesive films, pressure-sensitive tapes, surface protection films, surface protection tapes, masking tapes, electrical insulating tapes, laminates, adhesive tapes for electronic components such as circuit boards, packaging tapes, electrical insulating tapes, tapes for transporting electronic components, medical tapes, fabric tapes, anti-corrosion tapes, surface protection tapes, diaper tapes, and double-sided tapes for holding components.
• Polymers of (meth)acrylic monomers are acrylic polymers, which are so-called non-fluorinated resins.
• a non-flammable fluorinated solvent for example, a hydrofluoroether as the main component
• a (meth)acrylic monomer is used as the main component of the raw materials used to produce the polymerized composition.
• main component means that the (meth)acrylic monomer accounts for 50% by weight or more of the total raw materials before dissolving them in the polymerization solvent.
• This (meth)acrylic monomer can be divided into (meth)acrylate monomers that have one or more ester groups, and (meth)acrylic acid that has no ester groups.
• One or more types of substances can be used as the raw materials.
• a (meth)acrylic carboxyl group-containing monomer may be used as a substance contained in the raw material.
• the concept of this (meth)acrylic carboxyl group-containing monomer includes the above-mentioned (meth)acrylic acid.
• a (meth)acrylate monomer for example, one with 1 to 8 alkyl carbon atoms in the ester moiety can be selected.
• the alkyl group has a low carbon number, the material tends to be softer, and as the carbon number increases, the material tends to be harder. For this reason, one or more monomers with different carbon numbers can be freely selected as needed.
• Specific (meth)acrylate monomers that can be used include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, N-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, neopentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, heptyl (meth)acrylate, 2-ethylhexyl acrylate, N-octyl acrylate, isooctyl acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, t-butylcyclohexyl (meth)
• (meth)acrylate monomers include hydroxyl group-containing (meth)acrylates such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and glycerol (meth)acrylate, which have organic functional groups; epoxy group-containing monomers such as glycidyl (meth)acrylate, ⁇ -ethyl glycidyl acrylate, and 3,4-epoxybutyl (meth)acrylate; amino group-containing (meth)acrylate monomers such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate; (meth)acrylamide, N-t-butyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, and N-butoxymethyl (meth)acrylate; Examples of suitable monomers include monomers containing an amide,
• (Meth)acrylic carboxyl group-containing monomers include carboxyl group-containing monomers such as (meth)acrylic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxypropyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxypropyl phthalic acid, 2-(meth)acryloyloxyethyl maleic acid, 2-(meth)acryloyloxypropyl maleic acid, 2-(meth)acryloyloxyethyl succinic acid, and 2-(meth)acryloyloxypropyl succinic acid;
• Other monomers can also be used as appropriate, including carboxyl group-containing monomers such as crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, and monomethyl itaconate; acid anhydride group-containing
• a (meth)acrylate monomer among (meth)acrylic monomers that become compounds having a polymerizable unsaturated bond it is preferable to use methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl acrylate, or 2-ethylhexyl acrylate, and it is particularly preferable to use methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, or butyl (meth)acrylate.
• the shorter the carbon chain the stronger the odor tends to be.
• the reducing agent used in this embodiment can be a wide variety of common reducing agents that can donate electrons to the target substance, such as aluminum hydride reducing agents, borane reducing agents, borohydride reducing agents, metal hydride reducing agents, silane reducing agents, and triphenylphosphine.
• Reducing agents can be broadly classified into organic reducing agents and inorganic reducing agents, and both types of reducing agents can be used here.
• the reducing agent can be either a solid reducing agent, a liquid reducing agent, or a gaseous reducing agent.
• the reducing agent examples include lithium aluminum hydride, dimethylamine-borane, sodium borohydride (NaBH 4 ), triethylsilane, etc.
• the reducing agent used in this embodiment is preferably a borane compound or a silane compound, but the above reducing agents can be appropriately selected and used depending on the purpose and application.
• a silicon-hydrogen bond-containing compound (silane-based reducing agent) is used as the reducing agent.
• the silicon-hydrogen bond-containing compound can be one that has a silicon-hydrogen structure (group) within the compound. There can be one or more silicon-hydrogen structures (groups) within the silicon-hydrogen bond-containing compound, and there can also be multiple silicon-hydrogen structures (groups).
• the timing, method, and reaction temperature for adding the reducing agent can be selected and adjusted as appropriate, but it is best to add it in the latter half of the (meth)acrylic monomer polymerization reaction (when the conversion rate is 90% or higher) or once the polymerization reaction has been fully completed, and the reaction temperature should preferably be in the range of room temperature to approximately 100°C. When multiple types of (meth)acrylic monomers are used, it is preferable to add the reducing agent when the conversion rate of all (meth)acrylic monomers has reached 90% or higher.
• the amount of reducing agent added can be selected as appropriate, but is preferably 0.5% by weight to 10% by weight, and more preferably 1% by weight to 3% by weight, per 100 parts by weight of the (meth)acrylic monomer before the polymerization reaction.
• the effect per weight is greater when the number of silicon-hydrogen groups is relatively high compared to the molecular weight of the silicon-hydrogen bond-containing compound, i.e., the lower the molecular weight per silicon-hydrogen group.
• the theoretical amount of silicon-hydrogen bond-containing compound to be added is the amount that results in the number of double bond groups in the remaining (meth)acrylic monomer being the same as the number of silicon-hydrogen groups. However, because silicon-hydrogen groups also react with moisture, it is preferable to add an amount that is at least 1.1 times the molar ratio of the number of double bond groups in the remaining (meth)acrylic monomer, and preferably 1.3 times or more. Taking these theoretical values into consideration, by using an appropriate amount of silicon-hydrogen bond-containing compound as a scavenger, it is possible to reduce the amount of remaining (meth)acrylic monomer to 0.2% by weight or less, thereby suppressing odors.
• Silicon-hydrogen bond-containing compounds used as reducing agents include triethylsilane, tris(trimethylsilyl)silane, triphenylsilane, trihexylsilane, trisisopropylsilane, 1,1,2,2-tetraphenyldisilane, methyldiphenylsilane, dimethoxy(methyl)silane, dimethylphenylsilane, diethoxymethylsilane, diphenylsilane, phenylsilane, trichlorosilane, trimethoxysilane, triethoxysilane, tetramethyldisiloxane, pentamethyldisiloxane, and tetramethylcyclotetrasiloxane.
• triethylsilane is a particularly suitable material.
• Triethylsilane has a small molecular weight relative to its silicon-hydrogen content, resulting in a high concentration of silicon-hydrogen groups relative to the amount added.
• triethylsilane has a moderately high boiling point, so it does not evaporate even when heated to react as a reducing agent.
• triethylsilane remains in the final resin composition, it does not volatilize when applied to an object, and does not affect the appearance or physical properties of the coating film.
• the manufacturing process according to this embodiment may further contain a reduction catalyst to promote the addition and reduction reactions of the remaining (meth)acrylic monomer and reducing agent (e.g., a silicon-hydrogen bond-containing compound).
• reduction catalysts include, but are not limited to, chloroplatinic acid or a complex of chloroplatinic acid with an olefin such as ethylene, a complex of alcohol or vinylsiloxane, platinum/silica, alumina, or carbon.
• platinum group compounds besides platinum compounds include rhodium, ruthenium, iridium, and palladium-based compounds, such as RhCl(PPh3)3, RhCl(CO)(PPh3)2, RhCl(C2H4)2, Ru3(CO)12, IrCl(CO)(PPh3)2, and Pd(PPh3)4.
• the resin composition obtained by the polymerization reaction of (meth)acrylic monomers may contain (or may be added to) a crosslinking agent as needed.
• a crosslinking agent can be used, but they can be selected to suit the raw materials that make up the polymerized composition. Note that crosslinking requires a paired structure; for example, acrylic acid (-COOH) requires a hydroxyl group (-OH), and a hydroxyl group (-OH) requires acrylic acid or isocyanate (-NCO).
• a carboxyl group-containing monomer such as (meth)acrylic acid, 2-(meth)acryloyloxyethyl hexahydrophthalic acid, 2-(meth)acryloyloxypropyl hexahydrophthalic acid, 2-(meth)acryloyloxyethyl phthalic acid, 2-(meth)acryloyloxypropyl phthalic acid, 2-(meth)acryloyloxyethyl maleic acid, 2-(meth)acryloyloxypropyl maleic acid, 2-(meth)acryloyloxyethyl succinic acid, 2-(meth)acryloyloxypropyl succinic acid, crotonic acid, fumaric acid, maleic acid, itaconic acid, monomethyl maleate, or monomethyl itaconate is used as the (meth)acrylic monomer that constitutes the polymeric composition
• an epoxy resin, melamine resin, polyisocyanate, or the like can be used as the (
• hydroxyl group-containing (meth)acrylate such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, or glycerol (meth)acrylate
• epoxy resin, melamine resin, polyisocyanate, etc. can be used as a crosslinking agent.
• epoxy group-containing monomers such as glycidyl (meth)acrylate, ⁇ -ethylglycidyl acrylate, and 3,4-epoxybutyl (meth)acrylate are used as the (meth)acrylic monomers that make up the polymerized composition
• acids, amines, acid anhydrides, etc. can be used as crosslinking agents.
• the (meth)acrylic monomers that make up the polymeric composition include amino group-containing (meth)acrylate monomers such as dimethylaminoethyl (meth)acrylate and diethylaminoethyl (meth)acrylate, and monomers containing amide groups such as (meth)acrylamide, N-t-butyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, diacetone acrylamide maleic acid amide, and maleimide.
• epoxy resins, melamine resins, polyisocyanates, etc. can be used as crosslinking agents.
• an isocyanate group-containing (meth)acrylate such as 2-(meth)methacryloyloxyethyl isocyanate, 2-[0-(1'-methylpropylideneamino)carboxyamino]ethyl methacrylate, 2-[(3,5-dimethylpyrazolyl)carbonylamino]ethyl methacrylate, 1,1-(bisacryloyloxymethyl)ethyl isocyanate, 2-(2-methacryloyloxyethyloxy)ethyl isocyanate, or 2-isocyanatoethyl acrylate as the (meth)acrylic monomer that constitutes the polymeric composition, amine compounds, polyols, etc. can be used as crosslinking agents. These may be used alone or in combination of two or more.
• the resin composition may contain other additives as needed.
• additives that may be mixed include pigments such as titanium dioxide, inorganic or organic fillers, film-forming agents, plasticizers, antifreeze agents, preservatives, antifungal agents, antibacterial agents, antifoaming agents, dispersants, thickeners, leveling agents, pH adjusters, fibers, delustering agents, UV absorbers, antioxidants, light stabilizers, and tackifiers.
• the (meth)acrylic monomer can be polymerized using any conventional polymerization method, but radical polymerization is particularly desirable. Radical polymerization methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization can be freely selected depending on the type of solvent and the form of the final liquid.
• an initiator When an initiator is required for the above polymerization methods, a wide range of common initiators can be used.
• examples include benzoyl peroxide (BPO), lauroyl peroxide (LPO), and AIBN.
• Specific product names include Niper BW, Perloyl L, Perbutyl O, Perloyl IB, and Perloyl TCP (all manufactured by NOF Corporation). These can be selected and used as appropriate.
• a wide range of common chain transfer agents can be used in the polymerization process as needed.
• Specific examples include 1-butanethiol, 1-decanethiol, 1-dodecanethiol, 1-hexadecanethiol, 1-octanethiol, and thiophenol, and can be selected and used as appropriate.
• the polymerization reaction can be carried out without solvent, but organic solvents commonly used in radical polymerization or water can be used. Common organic solvents such as toluene, ethyl acetate, and butyl acetate can be used. However, since common organic solvents have flash points and odors, hexafluorometaxylene (HFMX) is preferred.
• a wide range of common organic solvents can be selected as the solution for dissolving (diluting) the resin composition obtained in this embodiment.
• fluorine solvents are desirable as they have advantages such as no flash point and a fast drying rate.
• one or more of hydrofluoroethers (HFEs), hydrofluoroolefins (HFOs), and hydrofluorocarbons (HFCs) can be selected.
• HFCs are preferred from the standpoint of solubility, but many have high ozone depletion potentials (ODPs) and global warming potentials (GWPs), so their use requires consideration of the burden on the environment.
• HFEs and HFOs do not have ODPs and many have relatively small GWPs, but they have slightly poorer solubility than HFCs, so these points should be considered when adopting them.
• HFEs include AE-3000 (AGC), Novec 7100 (3M), and Novec 7200 (3M); HFCs include Solkan 365mfc (Solvay); and HFOs include AS-300 (AGC) and Celefin 1233Z (Central Glass).
• the resin composition according to this embodiment is characterized by a low residual amount of (meth)acrylic monomer.
• a silicon-hydrogen bond-containing compound is used as a scavenger
• the resin composition obtained according to this embodiment will contain silicon atoms evenly distributed throughout the resin in the molar ratio of the added amount. Even if the resin composition contains silicon atoms, this does not adversely affect adhesive properties, etc.
• the method for producing a resin composition according to the present embodiment includes a polymerization step and a reducing agent addition step.
• Polymerization step (I) (Polymerization of Monomers)
• a (meth)acrylic monomer is dissolved in a polymerization solvent.
• An initiator is then added, and the temperature is raised to the desired polymerization temperature (for example, within a range of 10 to 220°C, specifically within a range of 50 to 120°C).
• the polymerization temperature may be set based on the 10-hour half-life temperature (T10) of the initiator (the temperature at which half of the initiator is decomposed in 10 hours). In practice, the temperature is set within a range of approximately T10 ⁇ 20°C.
• polymerization is carried out for the desired time (for example, between 3 and 50 hours) while monitoring the heat generated by polymerization and controlling the temperature so that the reaction solution temperature remains within the polymerization temperature range. This results in a polymerization reaction solution, in which the (meth)acrylic monomer remains.
• a reducing agent serving as a scavenger and a catalyst for accelerating the reaction are added, followed by stirring for a predetermined period of time (e.g., 10 minutes to 5 hours).
• a predetermined period of time e.g. 10 minutes to 5 hours.
• the remaining (meth)acrylic monomer and the reducing agent undergo a reduction and addition reaction, converting the (meth)acrylic monomer into substances other than the monomer.
• the amount of remaining (meth)acrylic monomer is 1.0 wt% or less, more preferably 0.5 wt% or less, and even more preferably 0.2 wt% or less. Note that in this embodiment, because the reducing agent is added as a scavenger for the remaining (meth)acrylic monomer, a portion (excess) of the added reducing agent remains in the final composition.
• end of the polymerization step (I) means that almost no further polymerization reaction will occur.
• sufficient time is ensured in the polymerization step (I), so the polymerization step (I) is temporarily terminated. Therefore, by performing the reducing agent addition step (II) after the polymerization step (I) is terminated, the reduction and addition reactions of the (meth)acrylic monomer remaining in the polymerization reaction solution are promoted. While this embodiment exemplifies the case in which the reducing agent is added after the polymerization reaction of the (meth)acrylic monomer is terminated in the polymerization step (I), the present invention is not limited to this.
• the reducing agent is added in the polymerization step (I) when the conversion rate of the (meth)acrylic monomer is 90% or higher. More preferably, the reducing agent is added when the conversion rate of the (meth)acrylic monomer is 95% or higher.
• Ethyl acrylate (EA/ethyl acrylate): carbon number 2 Butyl acrylate (BA/N-butyl acrylate): carbon number 4 2-Ethylhexyl acrylate (2EHA/2-ethylhexyl acrylate): carbon number 8 Isooctyl acrylate (IOA/isooctyl acrylate): carbon number 8 Methyl methacrylate (MMA/methyl acrylate): carbon number 1 Decyl acrylate (DA/decyl acrylate): carbon number 10 Lauryl acrylate (LA/lauryl acrylate): carbon number 12 Vinyl acetate (VAc): carbon number 2 Acrylic acid (AA/acrylic acid): carbon number 1 Hydroxyethyl acrylate (HEA/hydroxyethyl acrylate): carbon
• Example 1 [Polymerization step (I)] ⁇ Polymerization of Monomer> A reactor equipped with a stirrer, reflux condenser, thermometer, and nitrogen inlet tube was charged under a nitrogen atmosphere with 85 parts by weight of butyl acrylate (BA), 15 parts by weight of methyl methacrylate (MMA), and 173 parts by weight of hexafluorometaxylene (HFMX) as a fluorinated solvent for polymerization. 0.2 parts by weight of initiator lauroyl peroxide (LPO) was added, and the temperature was raised to 70°C.
• BA butyl acrylate
• MMA methyl methacrylate
• HMFX hexafluorometaxylene
• LPO lauroyl peroxide
• polymerization was carried out for 20 hours while controlling the temperature so that the reaction solution temperature was always 70 ⁇ 5°C, yielding a polymerization reaction solution.
• the monomer conversion was 100% for MMA and 97.6% for BA. In other words, it was confirmed that 2.4% BA remained.
• the reaction is preferably carried out until a conversion rate of 90% or more is reached, and more preferably until a conversion rate of 95% or more is reached. The method for measuring the conversion rate will be described later.
• step (II) ⁇ Addition of initiator>
• the polymerization reaction solution obtained in step (I) was heated to 90° C., and 0.1 parts by weight of an initiator LPO was added under normal pressure in a nitrogen atmosphere, followed by stirring for 60 minutes.
• a solution containing 1 part by weight of triethylsilane as a scavenger and 1 part by weight of platinum(0)-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex (2% xylene solution) as a catalyst was added to the polymerization reaction solution and stirred for 60 minutes.
• Step 1 The reaction solution before polymerization in the polymerization step (I) was diluted with tetrahydrofuran (THF) and subjected to gas chromatography (GC) measurement using a Shimadzu Gas Chromatography GC02014 under the measurement conditions of a temperature rise rate of 20°C/min and a temperature range of 50°C to 250°C.
• Step 2 The area ratio (monomer/HFMX) of the (meth)acrylic monomer component to the polymerization solvent obtained in the measurement of Procedure 1 was calculated and recorded.
• Step 3 At each verification timing, such as after the end of the polymerization step (I) and after the end of the reducing agent addition step (II), the polymerization reaction solution was sampled, and the same operations as in the above steps 1 and 2 were carried out to calculate and record the area ratio of the (meth)acrylic monomer component to the polymerization solvent (monomer/HFMX). These values were defined as the "post-reaction area ratio Si.”
• Step 4 The value obtained by the following calculation was taken as the conversion rate (%) at each verification timing. Calculation formula: ⁇ 1-(S0-Si)/S0 ⁇ 100(%) In the diagram of FIG. 1, when a plurality of types of (meth)acrylic monomers are used and the conversion rates of the respective (meth)acrylic monomers are different, the average value of the conversion rates of the respective (meth)acrylic monomers is shown.
• ⁇ Odor strength evaluation> The odor caused by the residual monomer in the resin composition was scored by sensory evaluation.
• the sensory evaluation was judged as follows: 1 indicates a good case where almost no odor was detected, 3 (standard) indicates a case where a slight odor derived from the monomer remained, 5 indicates the strongest odor (similar to that of Comparative Example 5), 2 indicates an intermediate score between 1 and 3, and 4 indicates an intermediate score between 3 and 5.
• Each sample was quantified by five people using this judging method, and the average score was calculated. An average score of 2 or less was rated as ⁇ , a score greater than 2 but less than 3.5 was ⁇ , and a score of 3.5 or more was x.
• test solution that was colorless and transparent with no floating matter or precipitate was rated as ⁇ ; a solution that was slightly cloudy but no floating matter or precipitate was observed was rated as ⁇ ; and a test solution that contained floating matter or precipitate was rated as ⁇ .
• ⁇ Adhesion evaluation> Approximately 3 ml of the verification solution prepared during the solubility evaluation was placed in a metal dish with a diameter of approximately 7 cm and dried at 130 ° C for 10 hours using a thermostatic chamber. Then, using a tensile tester, a cylindrical probe was lowered onto the adhesive coating deposited on the bottom of the metal dish and pressed against its circular end face to adhere it, and then the maximum pull-up stress (adhesive strength) when the probe was pulled up was measured.
• the probe was made of SUS304, the radius of the circular contact surface between the probe and the adhesive coating was 5 mm, the probe descent speed when adhering the probe to the adhesive coating was 10 mm/sec, the adhesion load between the probe and the adhesive coating was 2 N, the pressure time between the probe and the adhesive coating was 1 second, and the probe pull-up speed was 10 mm/sec.
• the pull-up stress adheresive strength
• Examples 2 to 4 The production and verification were carried out in the same manner as in Example 1, except that the type of reducing agent used in step (II) was changed.
• Example 5 The same production and verification were carried out as in Example 4, except that the type of (meth)acrylic monomer used in step (I) was changed.
• Example 9 Except for changing the type of (meth)acrylic monomer used in step (I), the same production and verification were carried out as in Example 4. Note that 10 parts by weight of decyl acrylate (DA) having 10 carbon atoms was used as the (meth)acrylic monomer.
• DA decyl acrylate
• Example 10 The production and verification were carried out in the same manner as in Example 8, except that the type and amount of the reducing agent added in step (II) were changed.
• Example 11 to 14 The production and verification were carried out in the same manner as in Example 1, except that the amount of the reducing agent added in step (II) was changed.
• step (I) isooctyl acrylate (IOA) and acrylic acid (AA) were used as (meth)acrylic monomers by referring to Patent Document 1.
• step (II) vinyl acetate was used as a scavenger. Except for these, the production and verification were carried out in the same manner as in Example 1.
• step (I) butyl acrylate (BA) and acrylic acid (AA) were used as the (meth)acrylic monomers by referring to Patent Document 2.
• step (II) triethylene glycol diacrylate was used as the scavenger. Except for these, the production and verification were carried out in the same manner as in Example 1.
• step (I) Decyl acrylate (DA) or lauryl acrylate (LA) was used as the (meth)acrylic monomer in step (I).
• step (II) no reducing agent (scavenger) was added. Except for these, the same production and verification were carried out as in Example 1.
• step (I) 2-ethylhexyl acrylate (2EHA) and perfluorohexylethyl acrylate (C6FA) were used as the (meth)acrylic monomers.
• step (II) no reducing agent (scavenger) was added. Except for these, the same production and verification were carried out as in Example 1.
• step (I) after confirming the heat of polymerization, polymerization was carried out for 20 hours while controlling the temperature of the reaction solution to maintain a constant temperature of 70 ⁇ 5°C, yielding a polymerization reaction solution. After 20 hours, the monomer conversion of the polymerization reaction solution was 100% for MMA and 77.4% for BA. In other words, it was confirmed that 22.6% of BA remained. In this state, the process proceeded to step (II), and the amount of reducing agent (triethylsilane) added was increased to 10 parts by weight. Other than that, the production and verification were carried out in the same manner as in Example 1.
• a reducing agent a silicon-hydrogen bond-containing compound with a silicon-hydrogen bond group
• a scavenger reduces the amount of (meth)acrylic monomer remaining in the produced resin composition. Specifically, the conversion rate of the (meth)acrylic monomer in the resin composition reaches 99.9% or more. At the same time, the adhesive properties of the resin product are not degraded. Furthermore, by adjusting the amount of reducing agent added, the odor of the monomer can be effectively removed.
• Example 9 when a (meth)acrylic monomer with an ester moiety containing more than 8 carbon atoms (specifically, decyl acrylate (DA)) is used, adhesion and solubility (particularly solubility in fluorine-containing solvents) are somewhat reduced.
• DA decyl acrylate
• the resin compositions produced in Examples 1 to 15 are widely soluble in organic solvents and alcohol-based solvents, demonstrating their environmental benefits.
• Comparative Examples 3 to 7 when a scavenger is not added, the conversion rate of the (meth)acrylic monomer is always below 98%. As seen in Comparative Examples 3 and 4, the adhesive strength is reduced and the resin composition is less soluble in fluorine-containing solvents. As seen in Comparative Examples 5 and 6, an odor is generated. As can be seen from Comparative Example 1, when vinyl acetate is used as a scavenger, the conversion rate of the (meth)acrylic monomer can be increased to 99.4%, but the residual vinyl acetate reduces the adhesive strength of the resin composition.
• a vinyl compound monomer (specifically, vinyl acetate) may be used among compounds having a polymerizable unsaturated bond.
• a vinyl polymer is produced by sufficiently carrying out a polymerization reaction of vinyl acetate, and then the vinyl polymer is reacted using triethylsilane as a reducing agent, thereby improving the final conversion rate of the monomer.
• an organic reducing agent is used as a scavenger, but the present invention is not limited to this.
• a polymerization reaction may be sufficiently carried out using butyl acrylate (BA), among compounds having a polymerizable unsaturated bond, and then sodium borohydride, which serves as an inorganic reducing agent, may be used as a scavenger. This can improve the final monomer conversion rate.
• BA butyl acrylate
• sodium borohydride which serves as an inorganic reducing agent
• butyl acrylate (BA) could be reduced by sodium borohydride.
• a solution prepared by adding sodium borohydride to butyl acrylate (BA) and diluting the solution with ethanol was subjected to gas chromatography (GC) analysis according to the above-described measurement method both before the reduction reaction (unheated) and after the reduction reaction (heated at 50°C for 4 hours).
• GC gas chromatography
• the peak indicated by arrow P1 before the reaction corresponds to butyl acrylate (BA), and the peak indicated by arrow Q2 after the reaction was confirmed by GC-MS analysis to be butyl propionate, the reduced form of butyl acrylate (BA).
• the addition of a reducing agent reduced butyl acrylate to butyl propionate.
• the amount of the remaining compound can be reduced by reacting a reducing agent as a scavenger. Furthermore, as with the third manufacturing method, it has been found that the amount of the remaining compound with polymerizable unsaturated bonds can also be reduced when an inorganic reducing agent (such as sodium borohydride) is used as a scavenger.
• an inorganic reducing agent such as sodium borohydride

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