WO2019059124A1 - Tackifier resin and pressure-sensitive adhesive composition - Google Patents

Abstract

A tackifier resin which comprises a rosin-based resin and a bridged cyclic compound having a melting point of 35-250°C and having 7-15 carbon atoms.

Description

Tackifier resin and pressure-sensitive adhesive composition

The present invention relates to a tackifying resin and a pressure-sensitive adhesive composition, and more particularly, to a tackifying resin for blending into a tackifying resin to improve tackiness, and a pressure-sensitive adhesive composition containing the tackifying resin.

Heretofore, it has been known to add an additive such as a tackifier to the adhesive in order to improve the adhesiveness.

As such a tackifier, specifically, for example, the content of components having a weight average molecular weight of 2000 to 3500, a hydroxyl value of 35 to 100 mg KOH / g, and a weight average molecular weight of 260 or less is 1.5% by weight or less A tackifier resin emulsion obtained by emulsifying a polymerized rosin ester resin is proposed (see, for example, Patent Document 1 below).

JP, 2010-106259, A

However, even when the tackifying resin emulsion described in the above-mentioned Patent Document 1 is blended in a pressure-sensitive adhesive, there is a problem that the pressure-sensitive adhesive does not have sufficient adhesiveness.

The present invention is a tackifier resin capable of improving the tackiness, and a pressure-sensitive adhesive composition containing the tackifier resin.

The present invention [1] contains a tackifier resin containing a rosin resin and a crosslinked ring compound having a melting point of 35 ° C. to 250 ° C. and a carbon number of 7 to 15.

The present invention [2] includes the tackifier resin according to the above-mentioned [1], wherein the crosslinked ring compound contains at least one selected from the group consisting of camphene, borneol and norbornene.

The present invention [3] contains the tackifier resin according to the above [1] or [2], wherein the softening point of the rosin resin is 95 to 160 ° C.

The present invention [4] contains the tackifier resin according to any one of the above [1] to [3], wherein the rosin resin is an acrylic acid-modified rosin ester.

In the present invention [5], the content ratio of the crosslinked ring compound is 0.01 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the total amount of the rosin resin and the crosslinked ring compound. And the tackifier resin according to any one of [4].

The present invention [6] contains a pressure-sensitive adhesive composition containing the tackifier resin according to any one of the above [1] to [5].

The tackifier resin of the present invention can impart excellent tackiness to the pressure-sensitive adhesive composition because it contains the above-mentioned specific component.

The pressure-sensitive adhesive composition of the present invention is excellent in tackiness since the tackifier resin of the present invention is contained.

The tackifying resin of the present invention is a resin composition containing a rosin resin and a crosslinked ring compound.

The rosin-based resin is not particularly limited, and examples thereof include unmodified rosin (unmodified rosin), rosin modified product (derivative) and the like.

Examples of the unmodified rosin include tall oil rosin (tall rosin), gum rosin, wood rosin and the like. These unmodified rosins can be used alone or in combination of two or more. The unmodified rosin preferably includes tall rosin and gum rosin, more preferably gum rosin. The gum rosin may be named according to the name of the place of production. As gum rosin, preferably, Chinese gum rosin and brazil gum rosin can be mentioned.

The rosin modified product is a modified product of the above-mentioned unmodified rosin, and examples thereof include acid modified rosin, ring structure-added rosin, disproportionated rosin, hydrogenated rosin, polymerized rosin and the like.

These rosin modifications can be used alone or in combination of two or more.

Examples of rosin-modified products preferably include acid-modified rosins, ring structure-added rosins, disproportionated rosins, and hydrogenated rosins, more preferably acid-modified rosins and ring structure-added rosins, and still more preferably acids Modified rosin is mentioned.

Examples of the acid-modified rosin include modified forms of the above-mentioned unmodified rosin with α, β-unsaturated carboxylic acids.

Specifically, the acid-modified rosin can be obtained, for example, by reacting the above-described non-modified rosin with an α, β-unsaturated carboxylic acid according to a known method.

Examples of α, β-unsaturated carboxylic acids include α, β-unsaturated carboxylic acids and acid anhydrides thereof, and specific examples thereof include fumaric acid, maleic acid, and maleic anhydride, Itaconic acid, citraconic acid, citraconic anhydride, acrylic acid, methacrylic acid and the like.

These α, β-unsaturated carboxylic acids can be used alone or in combination of two or more.

Preferred α, β-unsaturated carboxylic acids include acrylic acid.

In other words, as the acid-modified rosin, more preferably acrylic acid-modified rosin can be mentioned.

The blending ratio of the non-modified rosin and the α, β-unsaturated carboxylic acid is, for example, 1 mole or less of the α, β-unsaturated carboxylic acid with respect to 1 mole of the non-modified rosin. In the reaction of non-modified rosin with α, β-unsaturated carboxylic acids, the reaction temperature is, for example, 150 to 300 ° C., and the reaction time is, for example, 1 to 24 hours. In addition, in this reaction, known catalysts can be blended at an appropriate ratio, as necessary.

In the acid-modified rosin, the acid modification ratio (mass of α, β-unsaturated carboxylic acids relative to 100 parts by mass of non-modified rosin) is, for example, 1 part by mass or more, preferably 2 parts by mass or more. It is 10 parts by mass or less, preferably 9 parts by mass or less, more preferably 8 parts by mass or less.

In particular, from the viewpoint of improving adhesion, the acid modification rate (mass of α, β-unsaturated carboxylic acids relative to 100 parts by mass of non-modified rosin) is more preferably 4 parts by mass or more, particularly preferably 6 parts by mass It is above.

From the viewpoint of improving ball tack performance, the acid modification ratio (mass of α, β-unsaturated carboxylic acids relative to 100 parts by mass of unmodified rosin) is more preferably 6 parts by mass or less, particularly preferably 4 It is below a mass part.

Examples of the ring structure-added rosin include a modified form of the above-mentioned unmodified rosin with a (meth) acrylic acid ester having a carbocyclic ring.

Specifically, the ring structure-added rosin can be obtained, for example, by reacting the above-mentioned non-modified rosin with a (meth) acrylic acid ester having a carbocyclic ring by a known method (Diels-Alder reaction). it can.

As a (meth) acrylic acid ester having a carbocyclic ring, for example, cyclopropyl (meth) acrylate, cyclobutyl (meth) acrylate, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, bornyl (meth) acrylate, norbornyl (meth) (Meth) acrylic acid esters having an alicyclic group such as acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, adamantyl methyl (meth) acrylate, 2-methyladamantyl (meth) acrylate, dimethyladamantyl (meth) acrylate For example, phenyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxy polyethylene glycol (meth) acrylate (Meth) acrylic acid esters having an aromatic group such as nonyl phenoxy polyethylene glycol (meth) acrylate, phenoxy polypropylene glycol (meth) acrylate, biphenyl (meth) acrylate, ethoxylated ortho-phenylphenol (meth) acrylate and the like .

These (meth) acrylates having a carbocyclic ring can be used alone or in combination of two or more.

The (meth) acrylic acid ester having a carbocyclic ring preferably includes a (meth) acrylic acid ester having an alicyclic group, and more preferably isobornyl (meth) acrylate.

The blending ratio of the unmodified rosin to the (meth) acrylic ester having a carbocyclic ring is, for example, 0.1 to 50% by mass of the (meth) acrylic ester having a carbocyclic ring relative to 100 parts by mass of the unmodified rosin It is a department. In the reaction of non-modified rosin with (meth) acrylic acid ester having a carbon ring, the reaction temperature is, for example, 150 to 250 ° C., and the reaction time is, for example, 0.5 to 8 hours. In addition, in this reaction, known catalysts can be blended at an appropriate ratio, as necessary.

Also, as the rosin resin, for example, the above-mentioned ester of unmodified rosin and / or rosin modified product (rosin ester), amide compound of unmodified rosin and / or rosin modified product, unmodified rosin and / or rosin modified Also included are amine salts of the body, unmodified rosin and / or phenol-modified rosin-modified bodies, and the like.

Preferably, the above-mentioned ester of unmodified rosin and / or rosin modified product (rosin ester) can be mentioned.

The rosin ester can be obtained by reacting the above-described unmodified rosin and / or rosin modified product with a polyhydric alcohol by a known esterification method.

Examples of polyhydric alcohols include dihydric alcohols such as ethylene glycol, propylene glycol, neopentyl glycol, trimethylene glycol, tetramethylene glycol, 1,3-butanediol and 1,6-hexanediol, for example, glycerin, Trihydric alcohols such as methylol propane, trimethylol ethane, triethylol ethane, for example, tetrahydric alcohols such as pentaerythritol, for example, hexahydric alcohols such as dipentaerythritol, such as triethanolamine, tripropanolamine, triisopropanolamine And amino alcohols such as N-isobutyl diethanolamine and N-normal butyl diethanolamine. These polyhydric alcohols can be used alone or in combination of two or more. The polyhydric alcohol is preferably a trihydric alcohol or a tetrahydric alcohol, more preferably glycerin or pentaerythritol.

The mixing ratio of unmodified rosin and / or rosin modified product to polyhydric alcohol is such that the molar ratio of hydroxyl group of polyhydric alcohol to carboxyl group of unmodified rosin and / or rosin modified product (OH / COOH) is, for example, , 0.2 to 1.4.

Further, in the reaction of a non-modified rosin and / or a rosin modified product with a polyhydric alcohol, the reaction temperature is, for example, 150 to 300 ° C., and the reaction time is, for example, 2 to 30 hours. In addition, in this reaction, known catalysts can be blended at an appropriate ratio, as necessary.

These rosin resins can be used alone or in combination of two or more.

As these rosin resins, rosin resins having a predetermined softening point are preferably selected from the viewpoint of improving adhesion.

The softening point of the rosin-based resin is, for example, 80 ° C. or more, preferably 95 ° C. or more, more preferably 100 ° C. or more, still more preferably 105 ° C. or more, for example, 200 ° C. or less, preferably 180 ° C. It is below.

In particular, from the viewpoint of improving adhesion, the softening point of the rosin-based resin is more preferably 110 ° C. or more, particularly preferably 130 ° C. or more, and preferably 180 ° C. or less.

That is, if the softening point of the rosin resin is in the above range, the adhesive strength is improved. Therefore, for example, it is possible to obtain a tackifying resin excellent in adhesion to polyethylene and the like.

In addition, from the viewpoint of improving ball tack performance, the softening point of the rosin resin is, for example, 80 ° C. or more, preferably 95 ° C. or more, more preferably 100 ° C. or more, and for example, 200 ° C. or less. Preferably, it is 180 ° C. or less, more preferably 160 ° C. or less, still more preferably 140 ° C. or less, particularly preferably less than 130 ° C.

That is, when the softening point of the rosin resin is in the above range, a tackifier resin excellent in ball tack performance and the like can be obtained.

The softening point of the rosin resin is measured in accordance with JIS K 5902 5.3 (1969).

As a rosin resin having such a softening point, from the viewpoint of improving adhesion, an ester of a non-modified rosin and / or a rosin-modified product is preferably mentioned, and more preferably, an ester of a rosin-modified product And more preferably an esterified product of acid-modified rosin, and particularly preferably an esterified product of acrylic acid-modified rosin (acrylic acid-modified rosin ester).

The acid value of the rosin-based resin is, for example, 3 mg KOH / g or more, preferably 5 mg KOH / g or more, more preferably 7 mg KOH / g or more, still more preferably 9 mg KOH / g or more, particularly preferably 10 mg KOH / g The above is, for example, 500 mg KOH / g or less, preferably 400 mg KOH / g or less, more preferably 300 mg KOH / g or less, still more preferably 200 mg KOH / g or less, particularly preferably 150 mg KOH / g or less.

The acid value is measured in accordance with JIS K 5902 (2006).

The bridged ring compound is a polycyclic compound having a bridged structure. In the present invention, a crosslinked ring compound having a predetermined melting point and a predetermined carbon number is used as the crosslinked ring compound.

Specifically, the melting point of the crosslinked ring compound is 35 ° C. or more, preferably 40 ° C. or more, more preferably 45 ° C. or more, and 250 ° C. or less, preferably 230 ° C. or less, from the viewpoint of adhesiveness. More preferably, it is 210 ° C. or less.

The melting point is measured in accordance with JIS K 0064 (1992).

Further, the carbon number of the crosslinked ring compound is 7 or more, preferably 8 or more, more preferably 9 or more, and 15 or less, preferably 13 or less, more preferably 11 or less, from the viewpoint of adhesiveness. is there.

As such a bridged ring compound, more specifically, for example, a compound having a bicyclo [2.2.1] heptane structure, a compound having a bicyclo [2.2.2] octane structure, and the like can be mentioned.

The compound having a bicyclo [2.2.1] heptane structure is only required to contain the bicyclo [2.2.1] heptane structure in a part of the structure of the compound, and bicyclo [2.2.1]. It includes compounds in which heptane further forms a condensed ring with another ring, and also includes compounds in which the carbon-carbon bond of bicyclo [2.2.1] heptane is a double bond.

The same applies to compounds having a bicyclo [2.2.2] octane structure.

That is, a compound having a bicyclo [2.2.2] octane structure is only required to contain a bicyclo [2.2.2] octane structure in part of the structure of the compound, and a bicyclo [2.2.2] It includes compounds in which octane forms a condensed ring with another ring, and also compounds in which the carbon-carbon bond of bicyclo [2.2.2] octane is a double bond.

As a compound having a bicyclo [2.2.1] heptane structure, for example, camphene (melting point 45-46 ° C., carbon number 10), borneol (alias: dragon brain) (melting point 208 ° C., carbon number 10), D-camphor (Alias: camphor, camphor) (melting point 175-177, carbon number 10), norbornene (alias: 2-norbornene) (melting point 44-46 ° C, carbon number 7), (±) -camphorquinone (melting point 197-203 ° C , A compound having a bicyclic bicyclo [2.2.1] heptane structure such as C 10), eg, endo-tetrahydrodicyclopentadiene (melting point 75 ° C., C 10), exo-tetrahydrodicyclopentadiene ( The compound etc. which have tricyclic bicyclo [2.2.1] heptane structure of melting | fusing point 55 degreeC, C10, etc. are mentioned.

Examples of compounds having a bicyclo [2.2.2] octane structure include compounds having a tricyclic bicyclo [2.2.2] octane structure such as patcholol (melting point 56 ° C., carbon number 15), etc. Be

These bridged ring compounds can be used alone or in combination of two or more.

As the crosslinking ring compound, preferably a compound having a bicyclo [2.2.1] heptane structure or a compound having a bicyclo [2.2.2] octane structure is mentioned from the viewpoint of adhesiveness, and more preferably a bicyclo [2.2.2] octane structure. [2.2.1] A compound having a heptane structure is mentioned, more preferably a compound having a bicyclic bicyclo [2.2.1] heptane structure, still more preferably camphene, borneol, norbornene And D-camphor, particularly preferably camphene, borneol, norbornene.

In other words, the bridged ring compound preferably includes at least one selected from the group consisting of camphene, borneol and norbornene, and more preferably at least one selected from the group consisting of camphene, borneol and norbornene Become.

And tackifying resin is prepared by mixing rosin resin and a crosslinking ring compound.

In the tackifying resin, the content ratio of the crosslinking ring compound is, for example, based on 100 parts by mass of the total of the rosin resin and the crosslinking ring compound from the viewpoint of obtaining excellent adhesiveness (adhesive force and / or holding power). 0.01 parts by mass or more, preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, still more preferably 1 part by mass or more, particularly preferably 3 parts by mass or more, for example, 20 It is at most 15 parts by weight, more preferably at most 10 parts by weight, still more preferably at most 8 parts by weight, particularly preferably at most 5.5 parts by weight.

If the content ratio of the crosslinked ring compound is in the above range, adhesion can be improved.

The mixing method is not particularly limited, and for example, known mixing methods such as wet mixing and dry mixing can be adopted.

Thereby, a tackifier resin is obtained as a mixture (resin composition) of a rosin resin and a crosslinked ring compound.

And since the tackifying resin obtained in this way contains the above-mentioned specific component, it can impart excellent adhesiveness to the pressure-sensitive adhesive composition.

Moreover, tackifying resin is prepared as a tackifying resin emulsion as needed.

The tackifying resin emulsion is obtained, for example, by dispersing the tackifying resin in water using an emulsifying agent.

The emulsifier is not particularly limited, and examples thereof include anionic emulsifiers, nonionic emulsifiers, cationic emulsifiers, etc. These may be used alone or in combination of two or more.

As an emulsifier, Preferably, an anionic emulsifier and a nonionic emulsifier are mentioned.

Examples of anionic emulsifiers include organic sulfonic acids, alkali metal salts of sulfuric acid esters, ammonium salts and the like, and more specifically, for example, alkyl aryl sulfonates such as sodium dodecylbenzene sulfonate, eg, lauryl Alkyl (or alkenyl) sulfuric acid ester salts such as sodium sulfate, sodium oleyl sulfate, eg polyoxyethylene alkyl (or alkenyl) ether sulfuric acid ester salts such as sodium polyoxyethylene lauryl ether sulfate, sodium polyoxyethylene oleyl ether sulfate, eg , Polyoxyethylene nonyl phenyl ether sodium sulfate, polyoxyethylene styryl phenyl ether sodium sulfate, etc. polyoxyethylene alkyl aryl ether Sulfate ester salts, for example, alkyl sulfosuccinic acid ester salts such as sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, disodium polyoxyethylene lauryl sulfosuccinate and derivatives thereof, for example, alkyl diaryl ether disulfones such as sodium alkyl diphenyl ether disulfonate Acid salts and their derivatives. These can be used alone or in combination of two or more.

As the nonionic emulsifier, for example, polyoxyethylene alkyl (or alkenyl) ethers such as polyoxyethylene lauryl ether and polyoxyethylene oleyl ether, for example, poly such as polyoxyethylene nonyl phenyl ether and polyoxyethylene styryl phenyl ether Oxyethylene alkylphenyl ethers, for example sorbitan higher fatty acid esters such as sorbitan monolaurate, sorbitan trioleate, for example polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate, for example polyoxyethylene Polyoxyethylene higher fatty acid esters such as monolaurate and polyoxyethylene monooleate, for example, monoglycera oleate De, glycerin higher fatty acid esters such as stearic acid monoglyceride, such as polyoxyethylene-polyoxypropylene block copolymers. These can be used alone or in combination of two or more.

Moreover, as an emulsifier, a synthetic polymer type emulsifier is also mentioned. For example, synthetic polymer emulsifiers include, first, polymerizable monomers (eg, styrene, α-methylstyrene, vinyl toluene, (meth) acrylic acid, maleic acid, (meth) acrylic esters, acrylamide, vinyl acetate, Styrene sulfonic acid, isoprene sulfonic acid, vinyl sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamido-2-methylpropane sulfonic acid, etc., and other monomers copolymerizable therewith, etc. The polymer is polymerized, then an alkali (for example, sodium hydroxide, potassium hydroxide, ammonia, etc.) is added to the obtained polymer to form a salt, and then the obtained salt is dispersed in water to obtain water. It is obtained as a dispersible polymer.

These emulsifiers can be used alone or in combination of two or more.

The proportion of the emulsifier is not particularly limited, but is, for example, 1 part by mass or more, preferably 2 parts by mass or more, and for example, 10 parts by mass or less, preferably 5 parts by mass with respect to 100 parts by mass of tackifier resin. Part or less.

And as a method of obtaining a tackifying resin emulsion using an emulsifier, well-known emulsification methods, such as a solvent type emulsification method and a non-solvent type emulsification method, are employ | adopted, for example.

In the solvent emulsification method, first, the above tackifying resin is dissolved in an organic solvent to obtain a tackifying resin solution. The organic solvent is not particularly limited as long as it is a solvent capable of dissolving the tackifying resin, and examples thereof include chlorinated hydrocarbon solvents such as methylene chloride, for example, aromatic hydrocarbon solvents such as toluene and xylene, for example, Ketone solvents such as methyl ketone and methyl isobutyl ketone may, for example, be mentioned. These can be used alone or in combination of two or more. In addition, the compounding ratio in particular of an organic solvent and tackifying resin is not restrict | limited, According to the objective and a use, it sets suitably.

Then, in this method, the obtained tackifying resin solution is mixed with emulsified water in which the emulsifying agent and water are mixed and dissolved to prepare an aqueous emulsion of coarse particles, and then a known emulsifying and dispersing machine (for example, Fine emulsification is carried out using various mixers, a colloid mill, a high pressure emulsifying machine, a high pressure discharge type emulsifying machine, a high shear type emulsifying and dispersing machine, etc., and then heating under normal pressure or reduced pressure to remove the organic solvent. Thereby, a tackifying resin emulsion is obtained.

In the solventless emulsification method, first, a tackifier resin heated and melted under normal pressure or pressure is mixed with the above-described emulsified water to prepare an aqueous emulsion of coarse particles, and then the above-described emulsification dispersion is performed. Finely emulsify using a machine. Thereby, a tackifying resin emulsion is obtained.

In addition, in the solvent type emulsification method and the solventless emulsification method, it is also possible to adopt a phase inversion emulsification method in which a water-in-oil emulsion is first prepared and then phase inversion is performed on an oil-in-water emulsion.

The average particle diameter of the tackifying resin emulsion is, for example, 0.10 μm or more, preferably 0.20 μm or more, from the viewpoint of keeping the viscosity appropriate, and from the viewpoint of improving the storage stability and the mechanical stability. For example, it is 0.50 μm or less, preferably 0.40 μm or less.

And since the tackifying resin emulsion obtained in this way contains the tackifying resin which contains said specific component, the outstanding adhesiveness can be provided to an adhesive composition. In addition, when using a tackifying resin emulsion, a water-based adhesive composition is obtained as an adhesive composition.

Therefore, a tackifying resin (including the tackifying resin in the tackifying resin emulsion (the same applies hereinafter)) is suitably used for the production of the pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition contains, for example, a tackifying resin and a base resin.

As a base resin, (meth) acrylic resin is mentioned, for example.

A well-known (meth) acrylic resin can be used as a (meth) acrylic resin. Specifically, the (meth) acrylic resin is obtained as a polymer of a raw material monomer containing a (meth) acrylic acid ester as a main component.

Examples of (meth) acrylic esters include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate and (meth) acrylic Examples thereof include 2-ethylhexyl acid, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate and the like. These (meth) acrylic acid esters can be used alone or in combination of two or more.

Moreover, in order to improve storage stability etc., it is possible to make the raw material monomer contain (meth) acrylic acid copolymerizable with (meth) acrylic acid ester. Also, if necessary, other monomers copolymerizable with (meth) acrylic acid ester, such as vinyl acetate, styrene and the like can be contained. In addition, the polymerization method in particular of a raw material monomer is not restrict | limited, A well-known method is employable.

When a tackifying resin emulsion is used as the tackifying resin, a (meth) acrylic resin emulsion is preferably used as the (meth) acrylic resin.

A (meth) acrylic resin emulsion can be obtained, for example, by synthesizing a (meth) acrylic resin in the presence of a surfactant and water. As surfactant, the above-mentioned emulsifier is mentioned and it can be used individually or in combination of 2 or more types. Preferably, an anionic emulsifier and a nonionic emulsifier are mentioned. In addition, preferably, an emulsifier of the same type as the emulsifier used in preparation of the tackifying resin emulsion is mentioned.

In the pressure-sensitive adhesive composition, the mass of the tackifying resin (including the tackifying resin in the tackifying resin emulsion) and the (meth) acrylic resin (including the (meth) acrylic resin in the (meth) acrylic resin emulsion) The ratio is, for example, 5 parts by mass or more, preferably 10 parts by mass or more, and more preferably 15 parts by mass or more with respect to 100 parts by mass of the total amount of the tackifying resin and the (meth) acrylic resin. For example, it is 35 parts by mass or less, preferably 30 parts by mass or less, more preferably 25 parts by mass or less.

If the mass ratio of the tackifying resin and the (meth) acrylic resin is in the above-mentioned range, it is possible to obtain a pressure-sensitive adhesive composition which is excellent in tackiness.

In addition, the pressure-sensitive adhesive composition can optionally contain a crosslinking agent.

As a crosslinking agent, for example, an isocyanate crosslinking agent, an epoxy crosslinking agent, a silicone crosslinking agent, an oxazoline crosslinking agent, an aziridine crosslinking agent, a silane crosslinking agent, an alkyl etherified melamine crosslinking agent, a metal chelate crosslinking agent And known crosslinking agents such as peroxides.

These crosslinking agents can be used alone or in combination of two or more.

As a crosslinking agent, Preferably, an isocyanate type crosslinking agent is mentioned.

The blending ratio of the crosslinking agent is, for example, 0.05 parts by mass or more, preferably 0.1 parts by mass or more, and for example, 15 parts by mass or less, preferably 100 parts by mass of the (meth) acrylic resin. It is 10 parts by mass or less.

Furthermore, the pressure-sensitive adhesive composition can contain known additives, if necessary.

Examples of additives include fillers, thickeners, foaming agents, coloring agents (dyes, pigments, etc.), antioxidants, light stabilizers, heat stabilizers, flame retardants, protective colloids, film forming aids, etc. It can be mentioned.

These additives can be used alone or in combination of two or more.

The amount of addition of the additive and the timing of the addition are not particularly limited, and are appropriately set according to the purpose and application.

And since such an adhesive composition contains said tackifying resin, it is excellent in adhesiveness.

Therefore, the pressure-sensitive adhesive composition can be suitably used in various industrial fields as, for example, a pressure-sensitive adhesive sheet, a pressure-sensitive adhesive film, a pressure-sensitive adhesive paper, and the like.

Next, the present invention will be described based on examples and comparative examples, but the present invention is not limited by the following examples. In addition, "part" and "%" are mass references | standards unless there is particular mention. In addition, specific numerical values such as mixing ratios (content ratios), physical property values, parameters, etc. used in the following description are the mixing ratios corresponding to those described in the above-mentioned “embodiments for carrying out the invention” Substitutes the upper limit (numerical value defined as "below", "less than") or lower limit (numerical value defined as "above", "excess"), etc. of the corresponding description such as content ratio), physical property value, and parameters be able to.

In addition, the measuring method used by a synthesis example is explained in full detail below.

<Softening point (° C) measurement>
The softening point was determined by the following method (R & B (ring & ball) method) in accordance with JIS K 5902 5.3 (1969).

That is, about 20 g of the sample was placed in a beaker and melted as quickly as possible at a low temperature.

The sulfuric acid paper was then placed on a flat surface, the preheated ring placed on top of it, and the melted sample was poured so as not to contain air bubbles.

Then, after the sample was allowed to cool to room temperature, the raised portion from the plane including the upper end of the ring was scraped off and flattened with a slightly heated knife or soldering iron.

Next, water (in the case of a softening point of 90 ° C. or more, glycerin) was taken in a beaker so that the liquid level was 50 mm above the upper end of the ring, and the ball was placed at the center of the ring.

The softening point measuring device was then placed on an electric heater connected to a slider and heated. After reaching 40 ° C. (70 ° C. in the case of a glycerin bath) in the case of water, the temperature was raised at 5 ± 0.5 ° C./minute while confirming with a stopwatch.

Then, the temperature at which the sample softened and the placed ball contacted the temporary plate of the support was determined as the softening point.

The memory of the thermometer was read in units of 0.5 ° C., and the temperature was displayed.

Moreover, when using an automatic softening point measuring apparatus, since it displayed on a 0.1 degreeC unit, it was read, it rounded off the decimal point first decimal place, and displayed on a 1 degreeC unit.

The softening point can be measured, for example, by an automatic softening point measuring device (manufactured by Elex Scientific Co., Ltd.) that automates temperature rise and softening point measurement. However, sample preparation, adjustment of liquid level, etc. are as described above.

<Acid number (mg KOH / g) measurement>
Based on JIS K 5902 (2006), weigh 0.5 to 0.7 g, 100 ml with a chemical balance, and shake well until completely dissolved in a neutral solvent (toluene / methanol = 2: 1). After that, about 5 drops of 1% phenolphthalein were added, and the acid value was determined by titration with N / 5 KOH.

The end point of the titration was a point at which the measurement solution became slightly crimson and did not disappear within 30 seconds.

<Rosin ester>
Synthesis Example 1 (Rose-based resin A: Esterified product of acrylic acid-modified rosin (softening point 115 ° C.))
A 1 L flask was charged with 780 g of Chinese gum rosin (non-modified rosin), and heated and dissolved while flowing nitrogen 5 ml / min.

Then, when reaching 180 ° C., 19.5 g of acrylic acid (2.5 g with respect to 100 g of non-modified rosin) is charged while stirring molten Chinese gum rosin, and the reaction is further carried out, and when turbidity disappears, the reaction is performed It was finished.

Thus, 800 g of acrylic acid-modified rosin was obtained.

Thereafter, while flowing 5 ml / min of nitrogen, 100 g of acrylic acid-modified rosin was heated to 200 ° C., 12 g of pentaerythritol was added, and the liquid temperature was raised to 270 ° C. over 8 to 10 hours.

Subsequently, an esterification reaction was carried out at 270 ° C. for 16 to 20 hours to obtain an esterified product of acrylic acid-modified rosin (pentaerythritol ester).

This was named rosin resin A. The softening point of the rosin resin A was 115 ° C., and the acid value was 18 mg KOH / g.

Synthesis Example 2 (Rosin-based Resin B: Ester of Polymerized Rosin (Softening Point: 125 ° C.))
500 g of Chinese gum rosin (non-modified rosin) was charged into a 1 L four-necked flask, and 380 g of mineral spirits was added, and heated and dissolved while flowing nitrogen 5 ml / min.

Then, when it was completely melted and it became possible to stir, it was cooled to 130 ° C., 5 g of a zinc chloride catalyst was added, and reacted at the same temperature for 4 hours.

Then, the mixture was neutralized and washed three times or more with 0.5% aqueous sodium bicarbonate to obtain a crude polymerized rosin.

Furthermore, the resulting crude polymerized rosin was distilled to remove the decomposition product and the solvent contained, to obtain a polymerized rosin.

Thereafter, 100 g of polymerized rosin was heated to 200 ° C. while flowing nitrogen 5 ml / min, 10 g of pentaerythritol was added, and the liquid temperature was raised to 270 ° C. over 8 to 10 hours.

Subsequently, an esterification reaction was carried out at 270 ° C. for 16 to 20 hours to obtain an esterified product of a polymerized rosin (pentaerythritol ester).

This was named rosin resin B. The softening point of the rosin resin B was 125 ° C., and the acid value was 14 mg KOH / g.

Synthesis Example 3 (Rose resin C: Esterified product of acrylic acid modified rosin (softening point 130 ° C.
)
A mixture of brazil gum rosin and tall rosin (gum rosin: tall rosin = 6: 4 (mass ratio), non-modified rosin) 780 g was charged into a 1-L flask and heated to dissolve while flowing nitrogen 5 ml / min.

Next, when reaching 180 ° C., 50.7 g of acrylic acid (6.5 g with respect to 100 g of unmodified rosin) is charged while stirring molten Chinese gum rosin, and the reaction is further carried out, and when turbidity disappears, the reaction is carried out It was finished.

Thus, 830 g of acrylic acid-modified rosin was obtained.

Thereafter, while flowing nitrogen 5 ml / min, 100 g of acrylic acid-modified rosin was heated to 200 ° C., 15 g of pentaerythritol was added, and the liquid temperature was raised to 270 ° C. over 8 to 10 hours.

Subsequently, an esterification reaction was carried out at 270 ° C. for 16 to 20 hours to obtain an esterified product of acrylic acid-modified rosin (pentaerythritol ester).

This was designated as rosin resin C. The softening point of the rosin resin C was 130 ° C., and the acid value was 18 mg KOH / g.

Synthesis Example 4 (Rose-based resin D: Esterified product of acrylic acid-modified rosin (softening point 150 ° C.))
A mixture of brazil gum rosin and tall rosin (gum rosin: tall rosin = 6: 4 (mass ratio), non-modified rosin) 780 g was charged into a 1-L flask and heated to dissolve while flowing nitrogen 5 ml / min.

Next, when reaching 180 ° C., 62.4 g of acrylic acid (8.0 g with respect to 100 g of non-modified rosin) is charged while stirring molten Chinese gum rosin, and the reaction is further carried out, and when turbidity disappears, the reaction is performed It was finished.

Thus, 840 g of acrylic acid-modified rosin was obtained.

Thereafter, while flowing nitrogen 5 ml / min, 100 g of acrylic acid-modified rosin was heated to 200 ° C., 16 g of pentaerythritol was added, and the liquid temperature was raised to 270 ° C. over 8 to 10 hours.

Subsequently, an esterification reaction was carried out at 270 ° C. for 16 to 20 hours to obtain an esterified product of acrylic acid-modified rosin (pentaerythritol ester).

This was named rosin resin D. The softening point of the rosin resin D was 150 ° C., and the acid value was 18 mg KOH / g.

Synthesis Example 5 (Rosin-based resin E: Esterified product of maleic acid-modified rosin (softening point 105 ° C.))
A 1 L flask was charged with 780 g of Chinese gum rosin (non-modified rosin), and heated and dissolved while flowing nitrogen 5 ml / min.

Then, when reaching 180 ° C., 11.6 g of maleic acid (1.5 g with respect to 100 g of non-modified rosin) is charged while stirring molten Chinese gum rosin, and the reaction is further carried out, and when turbidity disappears, the reaction is performed It was finished.

This gave 792 g of maleic acid-modified rosin.

Then, while flowing 5 ml / min of nitrogen, 100 g of maleic acid-modified rosin was heated to 200 ° C., 5 g of glycerin and 11 g of pentaerythritol were added, and the liquid temperature was raised to 270 ° C. over 8 to 10 hours.

Subsequently, an esterification reaction was carried out at 270 ° C. for 16 to 20 hours to obtain an esterified product of maleic acid-modified rosin (ester of glycerin and pentaerythritol).

This was named rosin resin E. The softening point of the rosin resin E was 105 ° C., and the acid value was 11 mg KOH / g.

Synthesis Example 6 (Rose-based resin F: Ester of fumaric acid-modified rosin (softening point 105 ° C.))
A 1 L flask was charged with 780 g of Chinese gum rosin (non-modified rosin), and heated and dissolved while flowing nitrogen 5 ml / min.

Then, when 180 ° C. is reached, 35.0 g of fumaric acid (4.5 g with respect to 100 g of unmodified rosin) is charged while stirring molten Chinese gum rosin, and the reaction is further carried out, and the reaction is carried out when turbidity disappears It was finished.

Thus, 815 g of fumaric acid-modified rosin was obtained.

Thereafter, while flowing 5 ml / min of nitrogen, 100 g of fumaric acid-modified rosin was heated to 200 ° C., 12 g of glycerin was added, and the liquid temperature was raised to 270 ° C. over 8 to 10 hours.

Subsequently, an esterification reaction was carried out at 270 ° C. for 16 to 20 hours to obtain an esterified product of fumaric acid-modified rosin (glycerin ester).

This was named rosin resin F. The softening point of the rosin resin F was 105 ° C., and the acid value was 17 mg KOH / g.

<Tackifying resin>
Example 1
According to the formulation described in Table 1, the rosin resin A and the crosslinked ring compound were mixed to obtain a tackifier resin.

Further, the obtained tackifier resin was mixed with a base resin (trade name: Harriaclon 350B, an acrylic resin-based adhesive, manufactured by Harima Chemical Co., Ltd.) to obtain a pressure-sensitive adhesive composition.

Examples 2 to 13 and Comparative Examples 1 to 3
A tackifier resin and a pressure-sensitive adhesive composition were obtained in the same manner as in Example 1 except that the formulations described in Tables 1 to 3 were changed.

In Comparative Example 1, a rosin resin was treated as a tackifying resin without using a crosslinking ring compound.

<Evaluation>
(1) Adhesiveness The pressure-sensitive adhesive composition was coated on a polyethylene film (PE film, 25 μm, manufactured by JMT Co., Ltd., trade name Lumirror T60) as a substrate so that the film thickness after drying was 25 μm.

Then, after drying for 5 minutes at 100 ° C. in the atmosphere, the surface was covered with a peeling-treated 75 μm PET film (Panak Co., Ltd., trade name SPPET 7501 BU), and aged at 40 ° C. for 3 days to obtain an evaluation sheet. .

Thereafter, the adhesion when peeling the evaluation sheet from the PE film, and the ball tack and the holding power of the peeled evaluation sheet were evaluated according to JIS Z 0237 (2009).

The adhesive strength was measured at 23 ° C., the ball tack was measured at 23 ° C., and the holding power was measured at 40 ° C.

The details of the abbreviations in the table are described below.
Rosin-based resin A: Ester of acrylic acid-modified rosin obtained in Synthesis Example 1 (acrylic acid modification ratio 2.5% / rosin) softening point 115 ° C., acid value 18 mg KOH / g
Rosin-based resin B: Ester of polymerized rosin obtained in Synthesis Example 2, softening point 125 ° C., acid value 14 mg KOH / g
Rosin-based resin C: Ester of acrylic acid-modified rosin obtained in Synthesis Example 3 (acrylic acid modification ratio 6.5% / rosin) softening point 130 ° C., acid value 18 mg KOH / g
Rosin-based resin D: Ester of acrylic acid-modified rosin obtained in Synthesis Example 4 (acrylic acid modification rate 8.0% / rosin) softening point 150 ° C., acid value 18 mg KOH / g
Rosin-based resin E: Esterified product of maleic acid-modified rosin obtained in Synthesis Example 5 (maleic acid modification ratio 1.5% / rosin) softening point 105 ° C., acid value 11 mg KOH / g
Rosin-based resin F: Ester of fumaric acid-modified rosin obtained in Synthesis Example 6 (fumaric acid modification ratio 4.5% / rosin) softening point 105 ° C., acid value 17 mg KOH / g
T100: Terpene phenolic resin, trade name YS Polystar T100, Yashara Chemical TO 105: Aromatic modified terpene resin, trade name YS resin TO 105, Yasuhara Chemical Kanphen: Crosslinked ring compound, C ₁₀ H ₁₆ , melting point 45-46 ° C. Nippon Terpene Chemical Borneol: bridged ring compound, C ₁₀ H ₁₈ O, melting point 208 ° C., D-camphor, manufactured by Nippon Terpene Chemical Co., Ltd .: bridged ring compound, C ₁₀ H ₁₆ O, melting point 175 to 177 ° C. , C ₇ H ₁₀ , melting point 45-48 ° C., (meth) acrylic resin, manufactured by Tokyo Chemical Industry: base acrylic adhesive, trade name: Haricuron 350 B, manufactured by Harima Chemical Co., Ltd. The above invention is provided as an exemplary embodiment of the present invention However, this is only an example and if it is interpreted limitedly There. Variations of the invention that are apparent to those skilled in the art are within the scope of the following claims.

The tackifier resin and the pressure-sensitive adhesive composition of the present invention can be suitably used in pressure-sensitive adhesive sheets, pressure-sensitive adhesive films, pressure-sensitive paper, and the like in various industrial fields.

Claims (6)

1. Rosin-based resin,
   A tackifier resin comprising a crosslinking ring compound having a melting point of 35 ° C. or more and 250 ° C. or less and having 7 or more and 15 or less carbon atoms.
2. The tackifying resin according to claim 1, wherein the crosslinked ring compound comprises at least one selected from the group consisting of camphene, borneol and norbornene.
3. The tackifier resin according to claim 1, wherein the softening point of the rosin resin is 95 to 160 ° C.
4. The rosin resin is
   The tackifying resin according to claim 1, which is an acrylic acid-modified rosin ester.
5. With respect to a total amount of 100 parts by mass of the rosin resin and the crosslinked ring compound,
   The tackifier resin according to claim 1, wherein a content ratio of the crosslinked ring compound is 0.01 parts by mass or more and 20 parts by mass or less.
6. A pressure-sensitive adhesive composition comprising the tackifier resin according to claim 1.