Pressure-sensitive adhesive with static peel resistance

Abstract

The present invention relates to pressure-sensitive adhesive dispersion polymers, to a method for their preparation, and to uses of such pressure-sensitive adhesive dispersion polymers, as well as pressure-sensitive adhesive compositions comprising said pressure-sensitive adhesive dispersion polymers.More particularly, but not exclusively, the present invention relates to uses of the pressure-sensitive adhesive compositions, to pressure-sensitive adhesive sheets comprising such pressure-sensitive adhesive compositions, and to uses of the pressure-sensitive adhesive sheets.

Description

[Technical field]

[0001] The present invention relates to pressure-sensitive adhesive dispersion polymers, to a method for their preparation, and to uses of such pressure-sensitive adhesive dispersion polymers, as well as pressure-sensitive adhesive compositions comprising said pressure-sensitive adhesive dispersion polymers.More particularly, but not exclusively, the present invention relates to uses of the pressure-sensitive adhesive compositions, to pressure-sensitive adhesive sheets comprising such pressure-sensitive adhesive compositions, and to uses of the pressure-sensitive adhesive sheets. [Background technology]

[0002] The uses of self-adhesive labels vary from everyday items to long-lasting specialty applications. They consist of a support material and a pressure-sensitive adhesive layer that is either directly coated on the surface of the support material or transferred from a coated liner material. Labels are attached to a wide variety of substrate materials and surface textures. In many cases, the substrate is not flat but curved, e.g., a bottle. In these cases, the label is adapted to the contours of the substrate and is therefore curved. Most of the substrate materials are manufactured to be naturally flat. Even if the substrate material has a flexible appearance, the forced bending imposes a static stress on the pressure-sensitive adhesive (PSA), since the substrate material tends to return to a flat shape. If the PSA cannot withstand this static stress, the label will peel off from the label edge after a while, often referred to as "winging", "flagging" or "repulsion". This problem is exacerbated by tight radii and difficult substrates such as low surface energy materials or embossed surface textures. Rebound resistance is an inherent property that a PSA must have to be suitable for use on labels that are applied to curved contours.

[0003] One of the most common classes of PSA materials for labels are polyacrylates, especially aqueous polyacrylate dispersions. With the proper adjustment of viscoelastic properties and glass transition temperatures, polyacrylates are inherently tacky. Polyacrylates are colorless and transparent and are known to be resistant to aging even after long periods and exposure to weathering.

[0004] In EP 2913373 A1, good static peel strength of acrylic polymers is achieved by adding tackifier resins, such as rosin with a softening point below 105°C, and phenolic resins with a softening point between 105°C and 170°C. However, the use of tackifiers has many disadvantages. PSAs with tackifiers based on natural substances, such as rosin or terpene derivatives, often have the disadvantage of having a yellowish color and poor aging resistance. This is particularly undesirable for labels on transparent substrates, for articles that are used over a long period of time, or that are exposed to weathering, especially UV radiation, over a long period of time.

[0005] It is an object of the present invention to provide a polyacrylate PSA having excellent rebound resistance without the use of a tackifying resin. Summary of the Invention

[0006] The following section summarizes certain aspects of the present invention.

[0007] According to a first aspect, the present invention relates to a pressure-sensitive adhesive dispersion polymer obtained by emulsion polymerization of a monomer mixture comprising: (a) 60 to 95% by weight of one or more (meth)acrylic monomers that individually result in a homopolymer having a glass transition temperature (Tg) of −40° C. or less; (b) 5 to 40% by weight of one or more ethylenically unsaturated monomers that individually result in a homopolymer having a Tg of 15° C. or greater; (c) 0.1 to 5% by weight of one or more ethylenically unsaturated monomers having acid and / or hydroxyl functionality; (d) 0 to 0.5% by weight of one or more monomers having at least two ethylenically unsaturated groups, and (e) 0.01 to 0.50 weight percent of a chain transfer agent; wherein monomers (a)-(d) are different from one another, and the weight percentages are based on the total amount of monomers in the monomer mixture; the pressure sensitive adhesive dispersion polymer has a tan delta maximum within a temperature range of -25°C to -15°C and a tan delta value of 0.33 to 0.60 at 130°C; Tan delta is measured by dynamic mechanical analysis (DMA) using a parallel plate tool at an angular frequency of 10 rad / s.

[0008] The tan delta value of the pressure sensitive adhesive dispersion polymer at 130° C. can be from 0.34 to 0.55, preferably from 0.34 to 0.51, and more preferably from 0.38 to 0.45.

[0009] The one or more (meth)acrylic monomers (a) may individually result in a homopolymer having a glass transition temperature (Tg) in the range of -65°C to -40°C.

[0010] The one or more (meth)acrylic monomers (a) may be selected from 2-ethylhexyl acrylate, n-butyl acrylate, 3-methylbutyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, propyl acrylate, propylheptyl acrylate, heptadecyl acrylate, decyl methacrylate, dodecyl methacrylate, isodecyl methacrylate, octyl methacrylate, lauryl methacrylate, 2-methoxyethyl acrylate, 3-methoxypropyl acrylate, 3-ethoxypropyl acrylate, 3-methoxybutyl acrylate, hydroxybutyl acrylate, hydroxyethyl caprolactone acrylate, and combinations thereof, preferably 2-ethylhexyl acrylate, n-butyl acrylate, and combinations thereof, more preferably n-butyl acrylate.

[0011] The monomer mixture may include (a) 65 to 95 weight percent, preferably 70 to 93 weight percent, of one or more (meth)acrylic monomers that individually yield a homopolymer having a glass transition temperature (Tg) of −40° C. or less, where the weight percentages are based on the total amount of monomers in the monomer mixture.

[0012] The one or more ethylenically unsaturated monomers (b) are capable individually of resulting in homopolymers having a glass transition temperature (Tg) in the range of from 15°C to 150°C, preferably in the range of from 18°C ​​to 120°C.

[0013] The one or more ethylenically unsaturated monomers (b) are selected from the group consisting of acrylonitrile, 3,3,5-trimethylcyclohexyl acrylate, cyclohexyl acrylate, isobornyl acrylate, octadecyl acrylate, tert-butyl acrylate, 2-phenylethyl methacrylate, benzyl methacrylate, n-butyl methacrylate, cyclohexyl methacrylate, ethyl methacrylate, glycidyl methacrylate, hexadecyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, isopropyl methacrylate, methyl methacrylate, and neopentyl methacrylate. styrene, methoxystyrene, 2-methylstyrene, 3-methylstyrene, 4-ethylstyrene, 4-isopropylstyrene, 4-methoxy-2-methylstyrene, 4-methoxystyrene, 4-methylstyrene, 2-chlorostyrene, 4-bromostyrene, 4-chlorostyrene, 4-fluorostyrene, and combinations thereof, preferably methyl methacrylate, n-butyl methacrylate, styrene, and combinations thereof, more preferably methyl methacrylate.

[0014] The monomer mixture may include (b) 5 to 35 weight percent, preferably 7 to 30 weight percent, of one or more ethylenically unsaturated monomers that individually yield a homopolymer having a Tg of 15° C. or greater, where the weight percentages are based on the total amount of monomers in the monomer mixture.

[0015] The one or more ethylenically unsaturated monomers having an acid functionality (c) may be selected from ethylenically unsaturated carboxylic acid monomers, ethylenically unsaturated sulfonic acid monomers, ethylenically unsaturated phosphorus-containing acid monomers, preferably (meth)acrylic acid, crotonic acid, fumaric acid, itaconic acid, maleic acid, maleic anhydride, vinyl acetic acid, vinyl lactic acid, vinyl sulfonic acid, styrene sulfonic acid, 2-carboxyethyl (meth)acrylate, vinyl sulfonic acid, phenyl vinyl sulfonate, sodium 4-vinylbenzene sulfonate, 2-methyl-2-propene-1-sulfonic acid, 4-styrene sulfonic acid, 2-acrylamido-2-methyl-1-propane sulfonic acid, vinyl phosphonic acid, dimethyl vinyl phosphonate, diethyl vinyl phosphonate, diethyl allyl phosphonate, allyl phosphonic acid, and combinations thereof, more preferably (meth)acrylic acid.

[0016] The one or more ethylenically unsaturated monomers having a hydroxyl functionality (c) may be selected from allyl alcohol, vinyl alcohol, N-methylol acrylamide, 1-penten-3-ol, hydroxyalkyl esters of ethylenically unsaturated acids, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and hydroxyethyl caprolactone acrylate, and combinations thereof, preferably hydroxyalkyl esters of ethylenically unsaturated acids, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and hydroxyethyl caprolactone acrylate, more preferably hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and combinations thereof.

[0017] The one or more ethylenically unsaturated monomers (c) having an acid function and a hydroxy function may be selected from 3-allyloxy-2-hydroxy-1-propanesulfonic acid.

[0018] The monomer mixture may include (c) 0.2 to 4 weight percent, preferably 0.5 to 3 weight percent, of one or more ethylenically unsaturated monomers having acid and / or hydroxyl functionality, where the weight percentages are based on the total amount of monomers in the monomer mixture.

[0019] The one or more monomers having at least two ethylenically unsaturated groups (d) may be selected from diallyl phthalate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, 1,2-ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and combinations thereof.

[0020] The monomer mixture may include (d) 0 to 0.4 weight percent, preferably 0 to 0.2 weight percent, of one or more monomers having at least two ethylenically unsaturated groups, where the weight percentages are based on the total amount of monomers in the monomer mixture.

[0021] The chain transfer agent (e) may be selected from n-dodecyl mercaptan, carbon tetrachloride, carbon tetrabromide, bromotrichloromethane, 4-methylbenzenethiol, isooctyl 3-mercaptopropionate, tert-nonyl mercaptan, 4,4'-thiobisbenzenethiol, tert-dodecyl mercaptan, α-methylstyrene dimer, thioglycolic acid, 2-ethylhexyl thioglycolate, butyl 3-mercaptopropionate, 1,8-dimercapto-3,6-dioxaoctane, and combinations thereof, preferably n-dodecyl mercaptan.

[0022] The monomer mixture may include (e) 0.01 to 0.40 weight percent, preferably 0.01 to 0.25 weight percent, of a chain transfer agent, where the weight percent is based on the total amount of monomers in the monomer mixture.

[0023] According to a further aspect, the present invention relates to a method for preparing a pressure sensitive adhesive dispersion polymer as described above, the method comprising polymerizing a monomer mixture by emulsion polymerization to obtain a dispersion polymer, wherein the monomer mixture comprises: (a) 60 to 95% by weight of one or more (meth)acrylic monomers that individually result in a homopolymer having a glass transition temperature (Tg) of −40° C. or less; (b) 5 to 40% by weight of one or more ethylenically unsaturated monomers that individually result in a homopolymer having a Tg of 15° C. or greater; (c) 0.1 to 5% by weight of one or more ethylenically unsaturated monomers having acid and / or hydroxyl functionality; (d) 0 to 0.5% by weight of one or more monomers having at least two ethylenically unsaturated groups, and (e) 0.01 to 0.50% by weight of a chain transfer agent; wherein monomers (a)-(d) are different from one another, and the weight percentages are based on the total amount of monomers in the monomer mixture; the dispersion polymer has a tan delta maximum within the temperature range of -25°C to -15°C and a tan delta value of 0.33 to 0.60 at 130°C; Tan delta is measured by dynamic mechanical analysis (DMA) using a parallel plate tool at an angular frequency of 10 rad / s.

[0024] The tan delta value of the dispersed polymer at 130° C. can be from 0.34 to 0.55, preferably from 0.34 to 0.51, and more preferably from 0.38 to 0.45.

[0025] The one or more (meth)acrylic monomers (a) may individually result in a homopolymer having a glass transition temperature (Tg) in the range of -65°C to -40°C.

[0026] The one or more (meth)acrylic monomers (a) may be selected from 2-ethylhexyl acrylate, n-butyl acrylate, 3-methylbutyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, propyl acrylate, propylheptyl acrylate, heptadecyl acrylate, decyl methacrylate, dodecyl methacrylate, isodecyl methacrylate, octyl methacrylate, lauryl methacrylate, 2-methoxyethyl acrylate, 3-methoxypropyl acrylate, 3-ethoxypropyl acrylate, 3-methoxybutyl acrylate, hydroxybutyl acrylate, hydroxyethyl caprolactone acrylate, and combinations thereof, preferably 2-ethylhexyl acrylate, n-butyl acrylate, and combinations thereof, more preferably n-butyl acrylate.

[0027] The monomer mixture may include (a) 65 to 95 weight percent, preferably 70 to 93 weight percent, of one or more (meth)acrylic monomers that individually yield a homopolymer having a glass transition temperature (Tg) of −40° C. or less, where the weight percentages are based on the total amount of monomers in the monomer mixture.

[0028] The one or more ethylenically unsaturated monomers (b) are capable individually of resulting in homopolymers having a glass transition temperature (Tg) in the range of from 15°C to 150°C, preferably in the range of from 18°C ​​to 120°C.

[0029] The one or more ethylenically unsaturated monomers (b) are selected from the group consisting of acrylonitrile, 3,3,5-trimethylcyclohexyl acrylate, cyclohexyl acrylate, isobornyl acrylate, octadecyl acrylate, tert-butyl acrylate, 2-phenylethyl methacrylate, benzyl methacrylate, n-butyl methacrylate, cyclohexyl methacrylate, ethyl methacrylate, glycidyl methacrylate, hexadecyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, isopropyl methacrylate, methyl methacrylate, and neopentyl methacrylate. styrene, methoxystyrene, 2-methylstyrene, 3-methylstyrene, 4-ethylstyrene, 4-isopropylstyrene, 4-methoxy-2-methylstyrene, 4-methoxystyrene, 4-methylstyrene, 2-chlorostyrene, 4-bromostyrene, 4-chlorostyrene, 4-fluorostyrene, and combinations thereof, preferably methyl methacrylate, n-butyl methacrylate, styrene, and combinations thereof, more preferably methyl methacrylate.

[0030] The monomer mixture may include (b) 5 to 35 weight percent, preferably 7 to 30 weight percent, of one or more ethylenically unsaturated monomers that individually yield a homopolymer having a Tg of 15° C. or greater, where the weight percentages are based on the total amount of monomers in the monomer mixture.

[0031] The one or more ethylenically unsaturated monomers having an acid functionality (c) may be selected from ethylenically unsaturated carboxylic acid monomers, ethylenically unsaturated sulfonic acid monomers, ethylenically unsaturated phosphorus-containing acid monomers, preferably (meth)acrylic acid, crotonic acid, fumaric acid, itaconic acid, maleic acid, maleic anhydride, vinyl acetic acid, vinyl lactic acid, vinyl sulfonic acid, styrene sulfonic acid, 2-carboxyethyl (meth)acrylate, vinyl sulfonic acid, phenyl vinyl sulfonate, sodium 4-vinylbenzene sulfonate, 2-methyl-2-propene-1-sulfonic acid, 4-styrene sulfonic acid, 2-acrylamido-2-methyl-1-propane sulfonic acid, vinyl phosphonic acid, dimethyl vinyl phosphonate, diethyl vinyl phosphonate, diethyl allyl phosphonate, allyl phosphonic acid, and combinations thereof, more preferably (meth)acrylic acid.

[0032] The one or more ethylenically unsaturated monomers having a hydroxyl functionality (c) may be selected from allyl alcohol, vinyl alcohol, N-methylol acrylamide, 1-penten-3-ol, hydroxyalkyl esters of ethylenically unsaturated acids, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and hydroxyethyl caprolactone acrylate, and combinations thereof, preferably hydroxyalkyl esters of ethylenically unsaturated acids, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and hydroxyethyl caprolactone acrylate, more preferably hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and combinations thereof.

[0033] The one or more ethylenically unsaturated monomers (c) having an acid function and a hydroxy function may be selected from 3-allyloxy-2-hydroxy-1-propanesulfonic acid.

[0034] The monomer mixture may include (c) 0.2 to 4 weight percent, preferably 0.5 to 3 weight percent, of one or more ethylenically unsaturated monomers having acid and / or hydroxyl functionality, where the weight percentages are based on the total amount of monomers in the monomer mixture.

[0035] The one or more monomers having at least two ethylenically unsaturated groups (d) may be selected from diallyl phthalate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, 1,2-ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and combinations thereof.

[0036] The monomer mixture may include (d) 0 to 0.4 weight percent, preferably 0 to 0.2 weight percent, of one or more monomers having at least two ethylenically unsaturated groups, where the weight percentages are based on the total amount of monomers in the monomer mixture.

[0037] The chain transfer agent (e) may be selected from n-dodecyl mercaptan, carbon tetrachloride, carbon tetrabromide, bromotrichloromethane, 4-methylbenzenethiol, isooctyl 3-mercaptopropionate, tert-nonyl mercaptan, 4,4'-thiobisbenzenethiol, tert-dodecyl mercaptan, α-methylstyrene dimer, thioglycolic acid, 2-ethylhexyl thioglycolate, butyl 3-mercaptopropionate, 1,8-dimercapto-3,6-dioxaoctane, and combinations thereof, preferably n-dodecyl mercaptan.

[0038] The monomer mixture may include (e) 0.01 to 0.40 weight percent, preferably 0.01 to 0.25 weight percent, of a chain transfer agent, where the weight percent is based on the total amount of monomers in the monomer mixture.

[0039] Another aspect of the present invention relates to the use of the pressure sensitive adhesive dispersion polymers described above for the manufacture of a pressure sensitive adhesive.

[0040] Yet a further aspect of the present invention relates to a pressure sensitive adhesive composition comprising the pressure sensitive adhesive dispersion polymer described above.

[0041] The pressure sensitive adhesive compositions described above may be free of any tackifying resin.

[0042] Furthermore, according to another aspect, the present invention relates to the use of the above-mentioned pressure-sensitive adhesive composition for the manufacture of a pressure-sensitive adhesive sheet.

[0043] Another aspect of the present invention relates to a pressure-sensitive adhesive sheet comprising a supporting substrate coated on one surface with the pressure-sensitive adhesive composition described above.

[0044] The support substrate can be a fabric, a polymer film, a foamed polymer film, or paper. The fabric can be a nonwoven or woven material. The polymer film can be a polyolefin film, a polyester film, or a polyvinyl chloride film.

[0045] A further aspect of the present invention relates to the use of the pressure-sensitive adhesive sheets described above, preferably for labelling articles including packaging such as bottles and food packaging, and / or for stationery tapes and / or double-sided tapes.

[0046] Further, according to another aspect, the present invention relates to the use of a dispersed polymer having a tan delta maximum within a temperature range of -25°C to -15°C and a tan delta value of 0.33 to 0.60 at 130°C, the tan delta being measured by dynamic mechanical analysis (DMA) at an angular frequency of 10 rad / s using a parallel plate tool, for the manufacture of a pressure sensitive adhesive. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] The present invention relates to a pressure sensitive adhesive dispersion polymer obtained by emulsion polymerization of a monomer mixture comprising: (a) 60-95% by weight of one or more (meth)acrylic monomers, each of which results in a homopolymer having a glass transition temperature (Tg) of -40°C or less; (b) 5-40% by weight of one or more ethylenically unsaturated monomers, each of which results in a homopolymer having a Tg of 15°C or more; (c) 0.1-5% by weight of one or more ethylenically unsaturated monomers having acid and / or hydroxyl functionality; (d) 0-0.5% by weight of one or more monomers having at least two ethylenically unsaturated groups; and (e) 0.01-0.50% by weight of a chain transfer agent. The monomers (a)-(d) of the monomer mixture are different from each other, and the weight percentages are based on the total amount of monomers in the monomer mixture. The pressure sensitive adhesive dispersion polymer of the present invention has a tan delta maximum within the temperature range of -25°C to -15°C, and a tan delta value at 130°C of 0.33-0.60. Tan delta is measured by dynamic mechanical analysis (DMA) using a parallel plate tool at an angular frequency of 10 rad / s, as further described in the Examples.

[0048] As used herein, the term "tan delta," also referred to as damping coefficient, dissipation coefficient or loss factor, is defined as the ratio between the loss modulus (G") and the modulus of elasticity (G'). According to the present invention, the tan delta value at 130°C may be between 0.34 and 0.55, preferably between 0.34 and 0.51, more preferably between 0.38 and 0.45. Thus, the tan delta is at least 0.33, such as at least 0.34, or at least 0.35, or at least 0.38. The tan delta is 0.60 or less, such as 0.58 or less, 0.55 or less, 0.53 or less, 0.51 or less, 0.48 or less, or 0.45 or less. One of ordinary skill in the art would understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein.

[0049] The glass transition temperatures of the monomers identified above, which individually result in a certain homopolymer glass transition temperature (Tg), refer to the glass transition temperatures measured by differential scanning calorimetry (DSC). Those skilled in the art are aware that DSC is only sufficiently conclusive if, after the first heating cycle, the material sample is kept at a temperature at least 25°C higher than the highest glass transition temperature or melting temperature of the material, but at least 20°C lower than the lowest decomposition temperature of the material, for at least 2 minutes. The sample is then cooled to a temperature at least 20°C lower than the lowest glass transition temperature or melting temperature to be determined, where the cooling rate should be at most 20°C / min, preferably at most 10°C / min. After a further waiting period of a few minutes, the actual measurement is performed, during which the sample is heated at least 20°C higher than the highest melting or glass transition temperature, generally at a heating rate of 10°C / min or less. The respective maximum and minimum limit temperatures can be approximately identified in a simple preliminary measurement with separate samples.

[0050] According to the present invention, the monomer mixture comprises (a) at least 60% by weight of one or more (meth)acrylic monomers that individually provide a homopolymer having a glass transition temperature (Tg) of -40°C or less, where the weight percentage is based on the total amount of monomers in the monomer mixture. According to the present invention, the monomer mixture comprises (a) 60-95% by weight of one or more (meth)acrylic monomers that individually provide a homopolymer having a glass transition temperature (Tg) of -40°C or less, where the weight percentage is based on the total amount of monomers in the monomer mixture. The one or more (meth)acrylic monomers (a) can individually provide a homopolymer having a Tg of -90°C or more, for example, -85°C or more, or -80°C or more, or -75°C or more, or -70°C or more, or -65°C or more, or -55°C or more. One of ordinary skill in the art would understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein. Thus, the one or more (meth)acrylic monomers (a) may individually result in homopolymers having a Tg in the range of −90° C. to −40° C., preferably in the range of −85° C. to −40° C., more preferably in the range of −80° C. to −40° C., even more preferably in the range of −75° C. to −40° C., and most preferably in the range of −65° C. to −40° C. The glass transition temperature may be measured by DSC as described above.

[0051] The one or more (meth)acrylic monomers (a) that can be used in the present invention can be selected from 2-ethylhexyl acrylate, n-butyl acrylate, 3-methylbutyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, propyl acrylate, propylheptyl acrylate, heptadecyl acrylate, decyl methacrylate, dodecyl methacrylate, isodecyl methacrylate, octyl methacrylate, lauryl methacrylate, 2-methoxyethyl acrylate, 3-methoxypropyl acrylate, 3-ethoxypropyl acrylate, 3-methoxybutyl acrylate, hydroxybutyl acrylate, hydroxyethyl caprolactone acrylate, and combinations thereof, preferably 2-ethylhexyl acrylate, n-butyl acrylate, and combinations thereof, more preferably n-butyl acrylate.The one or more (meth)acrylic monomers (a) can be n-butyl acrylate.

[0052] The one or more (meth)acrylic monomers (a) that individually result in a homopolymer having a glass transition temperature (Tg) of -40°C or less are present in an amount of at least 60% by weight, for example at least 63% by weight, or at least 65% by weight, or at least 68% by weight, or at least 70% by weight, where the weight percentage is based on the total amount of monomers in the monomer mixture. The one or more (meth)acrylic monomers (a) that individually result in a homopolymer having a glass transition temperature (Tg) of -40°C or less can be present in an amount of 95% by weight or less, for example 93% by weight or less, or 90% by weight or less, where the weight percentage is based on the total amount of monomers in the monomer mixture. One of ordinary skill in the art will understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein. Thus, the monomer mixture of the present invention may comprise (a) 60-93% by weight, e.g., 60-90% by weight, or 65-90% by weight, of one or more (meth)acrylic monomers that individually provide a homopolymer having a glass transition temperature (Tg) of −40° C. or less, where the weight percentage is based on the total amount of monomers in the monomer mixture. The monomer mixture of the present invention may comprise (a) 60-95% by weight, preferably 65-95% by weight, more preferably 70-93% by weight, of one or more (meth)acrylic monomers that individually provide a homopolymer having a glass transition temperature (Tg) of −40° C. or less, where the weight percentage is based on the total amount of monomers in the monomer mixture.

[0053] According to the present invention, the monomer mixture comprises (b) 5-40% by weight of one or more ethylenically unsaturated monomers that individually provide homopolymers having a Tg of 15°C or higher, the weight percentage being based on the total amount of monomers in the monomer mixture. The one or more ethylenically unsaturated monomers (b) individually provide homopolymers having a glass transition temperature (Tg) of 15°C or higher, such as 18°C ​​or higher. The one or more ethylenically unsaturated monomers (b) can individually provide homopolymers having a glass transition temperature (Tg) of 180°C or lower, such as 150°C or lower, or 120°C or lower. One of ordinary skill in the art will understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein. Thus, the one or more ethylenically unsaturated monomers (b) can individually provide homopolymers having a glass transition temperature (Tg) in the range of 15°C to 150°C, preferably in the range of 15°C to 150°C, more preferably in the range of 18°C ​​to 120°C. The glass transition temperature can be measured by DSC as described above.

[0054] The one or more ethylenically unsaturated monomers (b) that can be used in the present invention include acrylonitrile, 3,3,5-trimethylcyclohexyl acrylate, cyclohexyl acrylate, isobornyl acrylate, octadecyl acrylate, tert-butyl acrylate, 2-phenylethyl methacrylate, benzyl methacrylate, n-butyl methacrylate, cyclohexyl methacrylate, ethyl methacrylate, glycidyl methacrylate, hexadecyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, isopropyl methacrylate, methyl methacrylate, neopentyl methacrylate, methyl ... The one or more ethylenically unsaturated monomers (b) may be selected from methyl methacrylate, octadecyl methacrylate, propyl methacrylate, tert-butyl methacrylate, styrene, methoxystyrene, 2-methylstyrene, 3-methylstyrene, 4-ethylstyrene, 4-isopropylstyrene, 4-methoxy-2-methylstyrene, 4-methoxystyrene, 4-methylstyrene, 2-chlorostyrene, 4-bromostyrene, 4-chlorostyrene, 4-fluorostyrene, and combinations thereof, preferably methyl methacrylate, n-butyl methacrylate, styrene, and combinations thereof, more preferably methyl methacrylate. The one or more ethylenically unsaturated monomers (b) may be methyl methacrylate.

[0055] The monomer mixture of the present invention comprises (b) 5-40 wt%, preferably 5-35 wt%, more preferably 7-30 wt%, of one or more ethylenically unsaturated monomers that individually result in a homopolymer having a Tg of 15° C. or higher, where the weight percentage is based on the total amount of monomers in the monomer mixture. Thus, the one or more ethylenically unsaturated monomers (b) that individually result in a homopolymer having a Tg of 15° C. or higher are present in an amount of at least 5 wt%, e.g., at least 6 wt%, or at least 7 wt%, or at least 9 wt%, where the weight percentage is based on the total amount of monomers in the monomer mixture. The one or more ethylenically unsaturated monomers (b) that individually result in a homopolymer having a Tg of 15° C. or higher are present in an amount of 40 wt% or less, e.g., 37 wt% or less, or 35 wt% or less, or 33 wt% or less, or 30 wt% or less, where the weight percentage is based on the total amount of monomers in the monomer mixture. One of ordinary skill in the art would understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein. Thus, the monomer mixture of the present invention may include (b) 5 to 35 wt. %, for example 5 to 33 wt. %, or 5 to 30 wt. %, or 6 to 30 wt. %, or 7 to 30 wt. %, of one or more ethylenically unsaturated monomers that individually yield a homopolymer having a Tg of 15° C. or greater, where the weight percentages are based on the total amount of monomers in the monomer mixture.

[0056] According to the present invention, the monomer mixture comprises (c) 0.1-5% by weight of one or more ethylenically unsaturated monomers having acid functionality and / or hydroxyl functionality. The monomer mixture may comprise (c) 0.1-5% by weight of one or more ethylenically unsaturated monomers having acid functionality. The monomer mixture may comprise (c) 0.1-5% by weight of one or more ethylenically unsaturated monomers having hydroxyl functionality. The monomer mixture may comprise (c) 0.1-5% by weight of one or more ethylenically unsaturated monomers having acid functionality and hydroxyl functionality. The weight percentages are based on the total amount of monomers in the monomer mixture.

[0057] The one or more ethylenically unsaturated monomers (c) having an acid functionality that can be used in the present invention can be selected from ethylenically unsaturated carboxylic acid monomers, ethylenically unsaturated sulfonic acid monomers, ethylenically unsaturated phosphorus-containing acid monomers. Ethylenically unsaturated carboxylic acid monomers suitable for use in the present invention include mono- and dicarboxylic acid monomers, monoesters of dicarboxylic acids, and carboxyalkyl esters of ethylenically unsaturated acids such as 2-carboxyethyl (meth)acrylate, and ethylenically unsaturated carboxylic acid derivatives such as ethylenically unsaturated dicarboxylic acid anhydrides. In carrying out the present invention, it is preferred to use ethylenically unsaturated aliphatic mono- or dicarboxylic acids or anhydrides containing 3 to 5 carbon atoms. Examples of monocarboxylic acid monomers include (meth)acrylic acid, crotonic acid, and examples of dicarboxylic acid monomers include fumaric acid, itaconic acid, maleic acid, and maleic anhydride. Examples of other suitable ethylenically unsaturated acids include vinyl acetate, vinyl lactate, vinyl sulfonic acid, 2-methyl-2-propene-1-sulfonic acid, styrene sulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, and salts thereof.

[0058] Examples of ethylenically unsaturated sulfonic acid monomers include vinyl sulfonic acid, phenyl vinyl sulfonate, sodium 4-vinylbenzenesulfonate, 2-methyl-2-propene-1-sulfonic acid, 4-styrenesulfonic acid, 3-allyloxy-2-hydroxy-1-propanesulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, and salts thereof.

[0059] Examples of ethylenically unsaturated phosphorus-containing acid monomers include vinyl phosphonic acid, dimethyl vinyl phosphonate, diethyl vinyl phosphonate, diethyl allyl phosphonate, allyl phosphonic acid, and salts thereof.

[0060] Preferably, the one or more ethylenically unsaturated monomers (c) having an acid functional group are selected from (meth)acrylic acid, crotonic acid, fumaric acid, itaconic acid, maleic acid, maleic anhydride, vinylacetic acid, vinyllactic acid, vinylsulfonic acid, styrenesulfonic acid, 2-carboxyethyl (meth)acrylate, vinylsulfonic acid, phenylvinylsulfonate, sodium 4-vinylbenzenesulfonate, 2-methyl-2-propene-1-sulfonic acid, 4-styrenesulfonic acid, 2-acrylamido-2-methyl-1-propanesulfonic acid, vinylphosphonic acid, dimethylvinylphosphonate, diethylvinylphosphonate, diethylallylphosphonate, allylphosphonic acid, and combinations thereof, more preferably (meth)acrylic acid. The one or more ethylenically unsaturated monomers (c) having an acid functional group can be (meth)acrylic acid.

[0061] The one or more ethylenically unsaturated monomers having hydroxyl functionality (c) that can be used in the present invention can be selected from allyl alcohol, vinyl alcohol, N-methylol acrylamide, 1-penten-3-ol, hydroxyalkyl esters of ethylenically unsaturated acids and combinations thereof, preferably hydroxyalkyl esters of ethylenically unsaturated acids.

[0062] Hydroxyalkyl esters of ethylenically unsaturated acids include hydroxyalkyl acrylate and hydroxyalkyl methacrylate monomers based on ethylene oxide, propylene oxide and higher alkylene oxides or mixtures thereof. Suitable examples of hydroxyalkyl esters of ethylenically unsaturated acids can be selected from hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyethyl caprolactone acrylate, and combinations thereof.

[0063] The one or more ethylenically unsaturated monomers (c) having acid and hydroxyl functions that can be used in the present invention can be chosen from 3-allyloxy-2-hydroxy-1-propanesulfonic acid.

[0064] The one or more ethylenically unsaturated monomers (c) having acid and / or hydroxyl functionality that can be used in the present invention are (meth)acrylic acid, crotonic acid, fumaric acid, itaconic acid, maleic acid, maleic anhydride, vinyl acetic acid, vinyl lactic acid, vinyl sulfonic acid, styrene sulfonic acid, 2-carboxyethyl (meth)acrylate, vinyl sulfonic acid, phenyl vinyl sulfonate, sodium 4-vinylbenzene sulfonate, 2-methyl-2-propene-1-sulfonic acid, 4-styrene sulfonic acid, 2-acrylamido-2-methyl-1-propane sulfonic acid, vinyl phosphonic acid, dimethyl vinyl phosphonate, diethyl vinyl phosphonate, diethyl allyl phosphonate, allyl phosphonic acid, allyl alcohol, vinyl alcohol, N-methylol acrylamide, 1-penten-3-ol, ethylene The hydroxyalkyl esters of ethylenically unsaturated acids, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and hydroxyethyl caprolactone acrylate, 3-allyloxy-2-hydroxy-1-propanesulfonic acid, preferably (meth)acrylic acid, hydroxyalkyl esters of ethylenically unsaturated acids, such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and hydroxyethyl caprolactone acrylate, and combinations thereof, more preferably (meth)acrylic acid, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, and combinations thereof.

[0065] The monomer mixture of the present invention comprises (c) 0.1-5.0 wt%, preferably 0.2-4.0 wt%, more preferably 0.5-3.0 wt%, of one or more ethylenically unsaturated monomers having acid and / or hydroxyl functionality, the weight percentage being based on the total amount of monomers in the monomer mixture. Thus, the one or more ethylenically unsaturated monomers having acid and / or hydroxyl functionality (c) are present in an amount of at least 0.1 wt%, such as at least 0.2 wt%, or at least 0.3 wt%, or at least 0.4 wt%, or at least 0.5 wt%, or at least 0.6 wt%, or at least 0.7 wt%, the weight percentage being based on the total amount of monomers in the monomer mixture. The one or more ethylenically unsaturated monomers having acid and / or hydroxyl functionality (c) are present in an amount of 5.0 wt% or less, such as 4.5 wt% or less, or 4.0 wt% or less, or 3.5 wt% or less, or 3.0 wt% or less, where the weight percentage is based on the total amount of monomers in the monomer mixture. One of ordinary skill in the art will understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein.

[0066] When the monomer mixture of the present invention includes (c) one or more ethylenically unsaturated monomers having an acid functionality, the one or more ethylenically unsaturated monomers having an acid functionality can be present in an amount of 0.1 to 2.6 wt%, preferably 0.1 to 2.5 wt%, more preferably 0.5 to 2.5 wt%, where the weight percentage is based on the total amount of monomers in the monomer mixture. Alternatively, when the monomer mixture of the present invention includes (c) one or more ethylenically unsaturated monomers having an acid functionality, the one or more ethylenically unsaturated monomers having an acid functionality can be present in an amount of 2.8 to 5.0 wt%, preferably 3.0 to 5.0 wt%, more preferably 3.0 to 4.5 wt%, where the weight percentage is based on the total amount of monomers in the monomer mixture.

[0067] According to the present invention, the monomer mixture of the present invention may contain 0.1-2.6% by weight, preferably 0.1-2.5% by weight, more preferably 0.5-2.5% by weight of one or more ethylenically unsaturated monomers having an acid functional group, where the weight percentage is based on the total amount of monomers in the monomer mixture.The monomer mixture of the present invention may contain 2.8-5.0% by weight, preferably 3.0-5.0% by weight, more preferably 3.0-4.5% by weight of one or more ethylenically unsaturated monomers having an acid functional group, where the weight percentage is based on the total amount of monomers in the monomer mixture.

[0068] According to the present invention, the monomer mixture comprises (d) 0-0.5 wt%, preferably 0-0.4 wt%, more preferably 0-0.2 wt%, of one or more monomers having at least two ethylenically unsaturated groups, the weight percentage being based on the total amount of monomers in the monomer mixture. Thus, the one or more monomers having at least two ethylenically unsaturated groups (d) are present in an amount of 0.5 wt% or less, for example 0.4 wt% or less, or 0.3 wt% or less, or 0.2 wt% or less, or 0.1 wt% or less, the weight percentage being based on the total amount of monomers in the monomer mixture.

[0069] The one or more monomers (d) having at least two ethylenically unsaturated groups that can be used in the present invention can be selected from diallyl phthalate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, 1,2-ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and combinations thereof.

[0070] The monomer mixture of the present invention comprises (e) 0.01-0.50 wt%, preferably 0.01-0.40 wt%, more preferably 0.01-0.25 wt%, of a chain transfer agent, where the weight percentage is based on the total amount of monomers in the monomer mixture. Thus, the chain transfer agent (e) is present in an amount of at least 0.01 wt%, for example at least 0.02 wt%, or at least 0.03 wt%, where the weight percentage is based on the total amount of monomers in the monomer mixture. The chain transfer agent (e) is present in an amount of 0.50 wt% or less, for example 0.45 wt% or less, or 0.40 wt% or less, or 0.35 wt% or less, or 0.30 wt% or less, or 0.25 wt% or less, or 0.20 wt% or less, where the weight percentage is based on the total amount of monomers in the monomer mixture. One of ordinary skill in the art would understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein.

[0071] The chain transfer agent (e) that can be used in the present invention can be selected from n-dodecyl mercaptan, carbon tetrachloride, carbon tetrabromide, bromotrichloromethane, 4-methylbenzenethiol, isooctyl 3-mercaptopropionate, tert-nonyl mercaptan, 4,4'-thiobisbenzenethiol, tert-dodecyl mercaptan, α-methylstyrene dimer, thioglycolic acid, 2-ethylhexyl thioglycolate, butyl 3-mercaptopropionate, 1,8-dimercapto-3,6-dioxaoctane, and combinations thereof, preferably n-dodecyl mercaptan. The chain transfer agent (e) can be n-dodecyl mercaptan.

[0072] According to the present invention, the amounts of monomers defined above for the preparation of the pressure sensitive adhesive dispersion polymer latex can total 100% by weight, based on the total amount of monomers in the monomer mixture.

[0073] The present invention further relates to the use of a dispersed polymer having a tan delta maximum within the temperature range of -25°C to -15°C and a tan delta value of 0.33 to 0.60 at 130°C for the manufacture of a pressure sensitive adhesive. Tan delta is measured by dynamic mechanical analysis (DMA) using a parallel plate tool at an angular frequency of 10 rad / s, as further described in the examples.

[0074] According to the present invention, the tan delta value of the dispersion polymer at 130°C can be between 0.34 and 0.55, preferably between 0.34 and 0.51, more preferably between 0.38 and 0.45. Thus, the tan delta is at least 0.33, such as at least 0.34, or at least 0.35, or at least 0.38. The tan delta is 0.60 or less, such as 0.58 or less, 0.55 or less, 0.53 or less, 0.51 or less, 0.48 or less, or 0.45 or less. One of ordinary skill in the art will understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein.

[0075] The dispersion polymer can be obtained by polymerizing by emulsion polymerization of a monomer mixture, wherein the monomer mixture comprises: (a) 60 to 95% by weight of one or more (meth)acrylic monomers that individually result in a homopolymer having a glass transition temperature (Tg) of −40° C. or less; (b) 5 to 40% by weight of one or more ethylenically unsaturated monomers that individually result in a homopolymer having a Tg of 15° C. or greater; (c) 0.1 to 5% by weight of one or more ethylenically unsaturated monomers having acid and / or hydroxyl functionality; (d) 0 to 0.5% by weight of one or more monomers having at least two ethylenically unsaturated groups, and (e) 0.01 to 0.50% by weight of a chain transfer agent; wherein monomers (a)-(d) are different from one another and the weight percentages are based on the total amount of monomers in the monomer mixture.

[0076] All variations regarding the compounds and their relative amounts used in preparing the pressure sensitive adhesive dispersion polymer of the present invention can be as described above.

[0077] Surprisingly, it has been found that the polymer dispersions of the present invention provide good rebound resistance and well-balanced adhesive and cohesive properties, especially when used as adhesive labels or sheets disposed on curved substrates that exert a static rebound stress on the adhesive.

[0078] Method for preparing the pressure sensitive adhesive dispersion polymer of the present invention The present invention relates to a method for preparing a pressure sensitive adhesive dispersion polymer, the method comprising emulsion polymerizing a monomer mixture to obtain a dispersion polymer, the monomer mixture comprising: (a) 60 to 95% by weight of one or more (meth)acrylic monomers that individually result in a homopolymer having a glass transition temperature (Tg) of −40° C. or less; (b) 5 to 40% by weight of one or more ethylenically unsaturated monomers that individually result in a homopolymer having a Tg of 15° C. or greater; (c) 0.1 to 5% by weight of one or more ethylenically unsaturated monomers having acid and / or hydroxyl functionality; (d) 0 to 0.5% by weight of one or more monomers having at least two ethylenically unsaturated groups, and (e) 0.01 to 0.50% by weight of a chain transfer agent; wherein monomers (a)-(d) are different from one another, and the weight percentages are based on the total amount of monomers in the monomer mixture; The dispersed polymer has a tan delta maximum within the temperature range of -25°C to -15°C, and a tan delta value of 0.33 to 0.60 at 130°C. Tan delta is measured by dynamic mechanical analysis (DMA) using a parallel plate tool at an angular frequency of 10 rad / s, as further described in the examples.

[0079] According to the present invention, the tan delta value at 130°C may be between 0.34 and 0.55, preferably between 0.34 and 0.51, more preferably between 0.38 and 0.45. Thus, the tan delta is at least 0.33, such as at least 0.34, or at least 0.35, or at least 0.38. The tan delta is 0.60 or less, such as 0.58 or less, 0.55 or less, 0.53 or less, 0.51 or less, 0.48 or less, or 0.45 or less. One of ordinary skill in the art will understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein.

[0080] All variations regarding the compounds and their relative amounts used in preparing the pressure sensitive adhesive dispersion polymer of the present invention can be as described above.

[0081] The pressure sensitive adhesive dispersion polymer according to the present invention can be made by any emulsion polymerization process known to those skilled in the art, provided that the monomer mixtures defined herein are used.

[0082] A seed dispersion can be used in the emulsion polymerization to prepare the pressure sensitive adhesive dispersion polymer of the present invention. Any seed particles known to those skilled in the art can be used.

[0083] The seed particles are preferably present in an amount of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the total ethylenically unsaturated monomers used in the polymer. Thus, the lower limit of the amount of seed particles can be 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4 or 2.5 parts by weight. The upper limit of the amount can be 10, 9, 8, 7, 6, 5.5, 5, 4.5, 4, 3.8, 3.6, 3.4, 3.3, 3.2, 3.1 or 3 parts by weight. One of ordinary skill in the art will understand that any range formed by any of the explicitly disclosed lower and upper limits is expressly encompassed herein.

[0084] The above-mentioned process for the preparation of pressure-sensitive adhesive dispersion polymers can be carried out in the presence or absence of one or more emulsifiers, in the presence or absence of one or more protective colloids and in the presence of one or more initiators at temperatures of 0 to 130° C., preferably 0 to 100° C., particularly preferably 20 to 95° C., very particularly preferably 40 to 90° C., including all values ​​and subvalues ​​therebetween, in particular 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120 and 125° C.

[0085] The initiator that can be used in carrying out the present invention can include water-soluble and / or oil-soluble initiators that are effective for polymerization purposes.Representative initiators are well known in the art, and include, for example, azo compounds (such as AIBN, AMBN, and cyanovaleric acid), inorganic peroxy compounds (such as hydrogen peroxide, sodium peroxydisulfate, potassium peroxydisulfate, and ammonium peroxydisulfate, peroxycarbonates, and peroxyborates), organic peroxy compounds (such as alkyl hydroperoxides, dialkyl peroxides, acyl hydroperoxides, and diacyl peroxides), and esters (such as tertiary butyl perbenzoate), as well as combinations of inorganic and organic initiators. Suitable initiators include 2,3-dimethyl-2,3-diphenylbutane, tert-butyl hydroperoxide, tert-amyl hydroperoxide, cumyl hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, isopropyl cumyl hydroperoxide, p-menthane hydroperoxide, 2,5-di(tert-butylperoxy)-2,5-dimethyl-3-hexyne, 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxanane, di(tert-butyl)peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, di(tert-butylperoxyisopropyl)benzene, tert-butylcumyl peroxide, di-(tert-amyl) -peroxide, dicumyl peroxide, butyl 4,4-di(tert-butylperoxy)valerate, tert-butylperoxybenzoate, 2,2-di(tert-butylperoxy)butane, tert-amyl peroxybenzoate, tert-butylperoxyacetate, tert-butylperoxy-(2-ethylhexyl)carbonate, tert-butylperoxyisopropylcarbonate, tert-butylperoxy-3,5,5-trimethyl-hexanoate, 1,1-di(tert-butylperoxy)cyclohexane, tert-amyl peroxyacetate, tert-amylperoxy-(2-ethylhexyl)carbonate, 1,1-di(tert-butylperoxy)-3,5,5-Trimethylcyclohexane, 1,1-di(tert-amylperoxy)cyclohexane, tert-butyl monoperoxy maleate, 1,1'-azodi(hexahydrobenzonitrile), tert-butyl peroxy isobutyrate, tert-butyl peroxy diethyl acetate, tert-butyl peroxy 2-ethylhexanoate, dibenzoyl peroxide, tert-amyl peroxy 2-ethylhexanoate, di(4 -methylbenzoyl) peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, ammonium peroxodisulfate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, 2,2'-azodi(2-methylbutyronitrile), 2,2'-azodi(isobutyronitrile), didecanoyl peroxide, potassium persulfate, dilauroyl peroxide, di(3,5,5-trimethylhexanoyl) peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, di(4-tert-butylcyclohexyl)peroxydicarbonate, diisopropyl peroxydicarbonate, tert-butyl peroxyneodecanoate, di-sec-butyl peroxydicarbonate, tert-amyl peroxyneodecanoate, cumyl peroxyneoheptanoate, di(3-methoxybutyl)peroxydicarbonate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, cumyl peroxyneodecanoate, diisobutyryl peroxide, and mixtures thereof. ,

[0086] The initiator may be used in an amount sufficient to initiate the polymerization reaction at the desired rate. Generally, an amount of initiator between 0.01 and 5 weight percent, preferably between 0.1 and 4 weight percent, based on the total weight of the monomers in the monomer mixture, is sufficient. The amount of initiator is most preferably between 0.01 and 2 weight percent, based on the total weight of the monomers in the monomer mixture. The amount of initiator includes all values ​​and subvalues ​​therebetween, particularly including 0.01, 0.1, 0.5, 1, 1.5, 2, 2.5, 3, 4 and 4.5 weight percent, based on the total weight of the monomers in the monomer mixture.

[0087] The above inorganic and organic peroxy compounds may also be used alone or in combination with one or more suitable reducing agents, as is well known in the art. Examples of such reducing agents include sulfur dioxide, alkali metal disulfites, alkali metal and ammonium hydrogen sulfites, thiosulfates, dithionite and formaldehyde sulfoxylate, hydroxylamine hydrochloride, hydrazine sulfate, iron(II) sulfate, copper naphthenate, glucose, sulfonic acid compounds such as sodium methanesulfonate, amine compounds such as dimethylaniline, and ascorbic acid. The amount of reducing agent is preferably 0.03 to 10 parts by weight per part by weight of the polymerization initiator.

[0088] Suitable surfactants or emulsifiers for stabilizing the dispersed polymer include conventional surfactants for polymerization processes. Surfactants can be added to the aqueous phase and / or the monomer phase. The effective amount of surfactant in the seeded process is the amount selected to support colloidal stabilization of the particles, minimizing interparticle contact and preventing agglomeration. In the non-seeded process, the effective amount of surfactant is the amount selected to determine particle size.

[0089] Representative surfactants include, for example, saturated and ethylenically unsaturated sulfonic acids or their salts, such as unsaturated hydrocarbon sulfonic acids and their salts, such as vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, etc.; aromatic hydrocarbon acids and their salts, such as p-styrene sulfonic acid, isopropenyl benzene sulfonic acid, vinyloxybenzene sulfonic acid, etc.; sulfoalkyl esters of acrylic and methacrylic acid, such as sulfoethyl methacrylate and sulfopropyl methacrylate and their salts, and 2-acrylamido-2-methylpropane sulfonic acid and its salts; alkylated diphenyloxide disulfonates, sodium dodecylbenzene sulfonate, dihexyl or dioctyl esters of sodium sulfosuccinate, sodium alkyl esters of sulfonic acids, ethoxylated alkylphenols, and ethoxylated alcohols; and fatty alcohol sulfates and fatty alcohol (poly)ether sulfates.

[0090] The type and amount of surfactant typically depends on the number of particles, their size and their composition. Typically, surfactants are used in an amount of 0-20% by weight, preferably 0-10% by weight, more preferably 0-5% by weight, based on the total weight of monomers in the monomer mixture. The amount of surfactant includes all values ​​and subvalues ​​therebetween, including in particular 0, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 and 19% by weight, based on the total weight of monomers in the monomer composition. The polymerization can be carried out without surfactants.

[0091] Alternatively, instead of or in addition to the above surfactants, protective colloids can be used. As used herein, the term "protective colloid" generally refers to water-soluble polymeric compounds used to stabilize finely dispersed polymer particles. Protective colloids can surround the particles with a film, thus preventing them from approaching each other and thus agglomerating or coagulating, for example by spatial expansion. Suitable colloids include polyhydroxy compounds, such as polyvinyl alcohol, partially acetylated polyvinyl alcohol, casein, hydroxyethyl starch, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, polysaccharides and degraded polysaccharides, polyethylene glycol, polyvinylpyrrolidone, ethylene glycol-propylene glycol block copolymers, and gum arabic. Preferred protective colloids are carboxymethyl cellulose, hydroxyethyl cellulose and hydroxypropyl cellulose. Generally, these protective colloids are used in a content of 0-10, preferably 0-5, more preferably 0-3 parts by weight, based on the total weight of the monomers. The amount of protective colloid includes all values ​​and subvalues ​​therebetween, especially 1, 2, 3, 4, 5, 6, 7, 8 and 9 weight percent, based on the total weight of monomer.

[0092] Pressure-sensitive adhesive composition The present invention relates to the use of a pressure-sensitive adhesive dispersion polymer as described above or obtained by a process as described above for the manufacture of a pressure-sensitive adhesive.

[0093] The present invention further relates to a pressure sensitive adhesive composition comprising the above pressure sensitive adhesive dispersion polymer.

[0094] All variations regarding the compounds and their relative amounts used in preparing the pressure sensitive adhesive dispersion polymer of the present invention can be as described above.

[0095] According to the present invention, the pressure-sensitive adhesive composition may contain a tackifier resin in addition to the pressure-sensitive adhesive dispersion polymer of the present invention. The tackifier resin may be one or more selected from various known tackifier resins such as rosin-based resins, terpene resins, modified terpene resins, phenolic resins, petroleum-based resins, styrene-based resins, coumarone-indene resins, ketone-based resins, and combinations thereof.

[0096] The term "rosin-based resin" refers to both rosin and rosin-derived resins. Examples of rosin include unmodified rosin (unprocessed rosin), such as gum rosin, wood rosin, or tall oil rosin, and modified rosin obtained from unmodified rosin by modification, such as hydrogenation, disproportionation, or polymerization. Suitable examples of rosin-derived resins include rosin esters, such as unmodified rosin esters, which are esters of unmodified rosin and alcohol, and modified rosin esters, which are esters of modified rosin and alcohol; unsaturated fatty acid modified rosin obtained by modifying rosin with unsaturated fatty acid; unsaturated fatty acid modified rosin esters obtained by modifying rosin esters with unsaturated fatty acid; rosin alcohols obtained by reducing carboxyl groups in rosin or in the above-mentioned various rosin derivatives (including rosin esters, unsaturated fatty acid modified rosins, and unsaturated fatty acid modified rosin esters); and metal salts of rosin or the above-mentioned various rosin derivatives. Suitable examples of terpene resins include terpenes (typically monoterpenes) such as α-pinene, β-pinene, d-limonene, l-limonene, and dipentene.Suitable examples of modified terpene resins include resins obtained by modifying terpene resins, such as styrene-modified terpene resins or hydrogenated terpene resins.Suitable examples of phenolic resins include terpene-phenolic resins, hydrogenated terpene-phenolic resins, alkylphenolic resins, and rosin-phenolic resins.

[0097] According to the present invention, the pressure-sensitive adhesive composition can include 2 to 80 parts by weight, preferably 5 to 60 parts by weight, more preferably 10 to 45 parts by weight of a tackifier resin, based on 100 parts by weight of the pressure-sensitive adhesive dispersion polymer of the present invention. Thus, the pressure-sensitive adhesive composition can include at least 2 parts by weight, for example at least 5 parts by weight, or at least 10 parts by weight, or at least 15 parts by weight of a tackifier resin, based on 100 parts by weight of the pressure-sensitive adhesive dispersion polymer of the present invention. The pressure-sensitive adhesive composition can include 80 parts by weight or less, for example 75 parts by weight or less, 60 parts by weight or less, 55 parts by weight or less, 50 parts by weight or less, 45 parts by weight or less, 40 parts by weight or less, 35 parts by weight or less of a tackifier resin, based on 100 parts by weight of the pressure-sensitive adhesive dispersion polymer of the present invention. One skilled in the art will understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein.

[0098] Preferably, the pressure-sensitive adhesive composition of the present invention may be free of any tackifying resin. The pressure-sensitive adhesive composition of the present invention may be substantially free of tackifying resin. As used herein, the term "substantially free" means that tackifying resin, if any, is present as an incidental impurity content, such as less than 0.04% by weight based on the total weight of the pressure-sensitive adhesive composition. According to the present invention, the pressure-sensitive adhesive composition of the present invention may be completely free of tackifying resin. As used herein, the term "completely free" means that no tackifying resin is present in the pressure-sensitive adhesive composition.

[0099] Surprisingly, it has been found that pressure sensitive adhesive compositions including the pressure sensitive adhesive dispersion polymers of the present invention provide good rebound resistance without the use of a tackifying resin.

[0100] The pressure-sensitive adhesive composition may further comprise a light stabilizer or anti-aging agent. The anti-aging agent may be a product based on a sterically hindered phenol, a phosphite, a thiosynergist, a sterically hindered amine or a UV absorber. The anti-aging agent may comprise a cresol derivative in which the aromatic ring is substituted by a thioalkyl chain at any two different positions, preferably ortho and meta to the OH group. Suitable examples of anti-aging agents include 4,6-bis(dodecylthiomethyl)-o-cresol, 4,6-bis(undecylthiomethyl)-o-cresol, 4,6-bis(decyl-thiomethyl)-o-cresol, 4,6-bis(nonylthiomethyl)-o-cresol or 4,6-bis(octylthiomethyl)-o-cresol. The pressure-sensitive adhesive composition of the present invention may comprise a light stabilizer or anti-aging agent in an amount ranging from 0.1 to 10% by weight, preferably from 0.2 to 5% by weight, more preferably from 0.5 to 3% by weight, based on the total solids content of the pressure-sensitive adhesive composition.

[0101] The pressure-sensitive adhesive composition may further include a rheological additive (thickener), an antifoaming agent, a degassing agent, a wetting agent, a flow control agent, and a combination thereof. The pressure-sensitive adhesive composition of the present invention may include a rheological additive (thickener), an antifoaming agent, a degassing agent, a wetting agent, a flow control agent, and a combination thereof in an amount ranging from 0.1 to 5% by weight based on the total solids content of the pressure-sensitive adhesive composition.

[0102] The pressure-sensitive adhesive composition may also include a filler, such as silicon dioxide, glass in the form of solid or hollow beads, microballoons, calcium carbonate, zinc oxide, titanium dioxide, aluminum oxide, aluminum hydroxide, and combinations thereof. According to the present invention, the pressure-sensitive adhesive composition of the present invention may include a filler in an amount ranging from 0.1 to 20% by weight, based on the total solids content of the pressure-sensitive adhesive composition.

[0103] The pressure-sensitive adhesive composition of the present invention is preferably aqueous. Non-aqueous solvents can be used in the pressure-sensitive adhesive composition of the present invention in small amounts, if necessary. The amount of non-aqueous solvent can be 3% by weight or less, preferably 2% by weight or less, more preferably 1.5% by weight or less, most preferably 1% by weight or less, especially 0.5% by weight or less, based on the solid content of the pressure-sensitive adhesive composition. Examples of suitable non-aqueous solvents include, but are not limited to, toluene, acetone, methyl ethyl ketone, cyclohexane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol methyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methyl ether, dimethylformamide, dimethyl sulfoxide, monohydric alcohols such as methanol and ethanol, and polyhydric alcohols. The pressure-sensitive adhesive composition is preferably free of non-aqueous solvents.

[0104] Pressure Sensitive Adhesive Sheets The present invention relates to the use of a pressure-sensitive adhesive composition as described above for the manufacture of a pressure-sensitive adhesive sheet.

[0105] The present invention further relates to a pressure-sensitive adhesive sheet comprising a support substrate coated on at least one surface with the above-mentioned pressure-sensitive adhesive composition. According to the present invention, the support substrate may additionally be coated with the pressure-sensitive adhesive composition of the present invention on the surface opposite to the surface of the support substrate coated with the pressure-sensitive adhesive composition.

[0106] The pressure-sensitive adhesive composition can be applied directly onto the support substrate and dried to form a pressure-sensitive adhesive layer. Alternatively, the pressure-sensitive adhesive composition can be applied onto a highly releasable surface, such as the surface of a release liner, the drug-treated backside of a support substrate, and dried to form a PSA layer on the surface, which pressure-sensitive adhesive layer can be transferred to the support substrate. The pressure-sensitive adhesive layer can be applied by any known method and commonly used coater, such as a gravure coater, reverse roll coater, kiss roll coater, dip roll coater, bar coater, knife coater, spray coater, curtain coater, etc. The pressure-sensitive adhesive layer of the present invention is typically formed continuously. Depending on the purpose and application, the pressure-sensitive adhesive layer can be formed in a regular or random pattern, such as dots, stripes, etc.

[0107] The pressure-sensitive adhesive composition is applied in an amount of 2 to 200 g / m2 relative to the surface area of ​​the support substrate. 2 , preferably 5 to 130 g / m 2 , more preferably 10 to 100 g / m 2 The coating weight can be applied to the surface of the support substrate at a coating weight in the range of at least 2 g / m2 based on the surface area of ​​the support substrate. 2 , e.g. at least 5 g / m 2 , or at least 10 g / m 2 , or at least 20 g / m 2 The coating weight can be up to 200 g / m2 based on the surface area of ​​the support substrate. 2 For example, 150 g / m 2 or less than 130g / m 2 or less than 120g / m 2 or less than 100g / m 2 A person of ordinary skill in the art would understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein.

[0108] According to the present invention, the support substrate can be a cloth, a polymer film, a foamed polymer film or paper. The thickness of the support substrate can be appropriately selected depending on the purpose. The support substrate typically has a thickness in the range of 2 to 1000 μm, for example, 10 to 500 μm, or 20 to 300 μm. Thus, the support substrate can have a thickness of at least 2 μm, for example, at least 5 μm, or at least 10 μm, or at least 20 μm, or at least 30 μm, or at least 50 μm. The support substrate can have a thickness of 1000 μm or less, for example, 500 μm or less, or 400 μm or less, or 300 μm or less, or 250 μm or less, or 200 μm or less, or 150 μm or less. A person skilled in the art will understand that any range between any of the explicitly disclosed lower and upper limits is disclosed herein. The surface to which the pressure-sensitive adhesive composition is applied to form the pressure-sensitive adhesive layer may be subjected to a surface treatment such as a primer coating or a corona discharge treatment.

[0109] The polymer film can be a polyolefin film, a polyester film, or a polyvinyl chloride film. The polyolefin sheet can contain a polyolefin, such as polyethylene or polypropylene or an ethylene-propylene copolymer, as a main component. The polyester film can contain a polyester, such as polyethylene terephthalate (PET) or polybutylene terephthalate, as a main component. The polyvinyl chloride film can contain polyvinyl chloride as a main component. The plastic film according to the present invention can be a non-stretched film or a stretched film, such as a uniaxially stretched film or a biaxially stretched film. According to the present invention, the plastic film can have a thickness in the range of 5 to 200 μm, for example 10 to 100 μm.

[0110] The fabric can be a nonwoven or woven material. The nonwoven or woven material of the present invention can be a single fiber material or a blend of various fiber materials. Suitable examples of nonwoven materials include nonwoven materials composed of natural fibers, including pulp, such as wood pulp, cotton, hemp, and combinations thereof; nonwoven materials composed of synthetic fibers, including polyester fibers, such as polyethylene terephthalate (PET) fibers, rayon fibers, vinylon fibers, acetate fibers, polyvinyl alcohol (PVA) fibers, polyamide fibers, polyolefin fibers, polyurethane fibers, and combinations thereof; and nonwoven materials composed of combinations thereof. According to the present invention, the fabric, preferably the nonwoven or woven material, can have a thickness in the range of 10 to 300 μm, for example, 20 to 250 μm, or 50 to 200 μm.

[0111] The foamed polymer film may be formed from a foam such as a polyurethane foam, a polyethylene foam, a polyacrylate foam or a polychloroprene foam. According to the present invention, the foamed polymer film may have a thickness in the range of 10 to 500 μm, for example, 20 to 300 μm.

[0112] According to the invention, the paper may have a thickness in the range of 20 to 200 μm, for example 30 to 150 μm.

[0113] The present invention further relates to the use of the pressure-sensitive adhesive sheet of the present invention for labeling articles and / or for stationery tapes and / or double-sided tapes. The articles to be labeled can be flat or curved articles, including packaging such as bottles and food packaging.

[0114] The invention will now be further described with reference to the following examples. EXAMPLES

[0115] In what follows, all parts and percentages are by weight unless otherwise stated.

[0116] Preparation of pressure sensitive adhesive dispersion polymer The pressure sensitive adhesive dispersion polymer was prepared by a free radical emulsion polymerization process combining an initial reactor charge with two reactant feeds: A double-walled 6 liter glass reactor equipped with a blade magnetic stirrer and connected to a cryostat allowing temperature control was charged with 800 g of deionized water and 40 g of polymethyl methacrylate seed dispersion with 20% solids and an average particle size of 30 nm.

[0117] 2.76 kg of reactants (according to Tables 1 and 2), 22.8 g of anionic surfactant (C 13 -C 15 A monomer pre-emulsion of 1.2 kg of alkylarylsulfonate and 1.2 kg of deionized water was prepared and treated with a dissolver disk for 5 minutes to obtain a homogeneous monomer emulsion. Additionally, an initiator solution was prepared by dissolving 8 g of sodium persulfate in 72 g of deionized water.

[0118] The initial charge was heated to 85° C. under stirring, after which the monomer pre-emulsion and initiator solution were continuously fed into the reactor over a period of 4 hours. The reaction temperature was kept constant at 85° C. The monomer inlet was finally flushed with 50 g of water. The batch was stirred for another 30 minutes and then cooled to 60° C. For post-activation, 2.5 g of a 5% solution of erythorbic acid was fed into the batch over 1 hour, and a first shot of 1.1 g of a 10% solution of tert-butyl hydroperoxide was added at the start of the erythorbic acid feed and a second shot 30 minutes later.

[0119] The batch was then cooled to ambient temperature (20-25°C), neutralized to pH 7.5 with 10% sodium hydroxide solution, sieved through a 100 μm filter cloth, and adjusted to a total solids content of 52%. The particle size of the sample dispersion was found to be 210-230 nm, as measured by a Mastersizer 2000 (commercially available from Malvern Panalytical, Great Britain).

[0120] The examples were characterized for their viscoelastic properties via dynamic mechanical analysis (DMA) with a dynamic mechanical analyzer MCR302e (all from Anton Paar, Austria) equipped with a Peltier temperature controlled lower plate (P-PTD200, diameter 56 mm) and a Peltier hood (H-PTD200) for good temperature control. Test specimens were made by diluting the dispersions to 40% solids, pouring a very large amount of the dispersion into a 30 mm diameter disc-shaped silicone mold and drying for 2 days at ambient conditions (20-25 °C), resulting in a film thickness of 0.6-0.8 mm. Film formation was completed by heating the dried samples in an oven at 80 °C for 5 h and reconditioning them for 24 h at standard climatic conditions (temperature 23 ± 1 °C, controlled relative humidity 50 ± 5%). Disks of 15 mm diameter were punched out of the sample films and placed between parallel plates with a 15 mm diameter top plate, carefully ensuring that complete contact was made between the sample and the plates. Temperature sweeps from -40 to 130 °C with a heating rate of 2 K / min were recorded under a constant normal force of 1 N, a constant angular frequency of 10 rad / s and a logarithmic deformation ramp of 0.02 to 2%.

[0121] The maximum value of loss angle tangens Delta (tan delta max) was evaluated as a measure of the dynamic glass transition temperature, and the tan delta value was read at 130° C. The tan delta max values ​​and the tan delta values ​​at 130° C. for Examples 1-7 are shown in Table 1, and for Examples 8-12 in Table 2.

[0122] [Table 1]

[0123] [Table 2]

[0124] The repulsion resistance of these examples was measured as follows. The dispersions of Examples 1 to 12 were applied to a 350 μm-thick biaxially oriented PET film Mylar (trademark) A (manufactured by DuPont Teijin Films, Luxembourg) at a concentration of 40 g / m after drying in an oven at 80° C. for 10 minutes. 2 The film was stretched using a doctor blade so that a coating weight of 100 mm was obtained. The self-adhesive sheet was cut into pieces 25 mm wide and 100 mm long. The pieces were conditioned for 24 hours in a climatic chamber with a temperature of 23±1° C. and a controlled relative humidity of 50±5%. A piece of pipe made of rigid PVC with an outside diameter of 110 mm, which served as a curved substrate according to DIN EN1401-1, was kept in the same environment for 24 hours. Before applying the samples, the outer surface of the pipe was carefully cleaned by wiping it with a cloth moistened with acetone.

[0125] The rectangular specimen was placed on the PVC pipe with the long side oriented perpendicular to the axis of the pipe to achieve maximum bending. Care was taken to ensure complete contact of the adhesive with the pipe surface, and air entrapment was carefully avoided using a plastic squeegee. Immediately after placing the specimen, a rubber-coated roller weighing 2 kg was used to press firmly against the pipe surface and move slowly back and forth three times. One of the two short ends of the specimen was further fixed with duct tape (Tesa™ Extrapower, Tesa SE, Germany) overlapping the specimen edge by 5 mm, allowing peeling only from the opposite short end.

[0126] The pipe pieces were then placed in an oven heated to 40°C and after 72 hours the behaviour of the samples was assessed in terms of peel distance from the pipe in millimeters (mm) and failure mode (presence or absence of adhesive residue observed under the peeled area), which indicated whether the cohesive properties of the pressure sensitive adhesive sample were fairly strong or weak.

[0127] The evaluation was performed as shown in Tables 3 and 4.

[0128] [Table 3]

[0129] [Table 4]

[0130] The repulsion resistance of Examples 1 to 7 is shown in Table 5, and that of Examples 8 to 12 is shown in Table 6.

[0131] [Table 5]

[0132] [Table 6]

Claims

1. Pressure-sensitive adhesive dispersion polymer obtained by emulsion polymerization of monomer mixtures: However, the preset mixture is (a) One or more (meth)acrylic monomers, each yielding a homopolymer having a glass transition temperature (Tg) of -40°C or lower, in an amount of 60 to 95% by weight. (b) One or more ethylenically unsaturated monomers that yield homopolymers having a Tg of 15°C or higher, in an amount of 5 to 40% by weight. (c) 0.1 to 5% by weight of one or more ethylenically unsaturated monomers having acidic functional groups and / or hydroxyl functional groups. (d) 0 to 0.5% by weight of one or more monomers having at least two ethylenically unsaturated groups, and (e) Containing 0.01 to 0.50% by weight of a chain transfer agent, Here, monomers (a) to (d) are different from each other, and the weight percentage is based on the total amount of monomers in the monomer mixture. The pressure-sensitive adhesive dispersion polymer has a maximum tan delta value within the temperature range of -25°C to -15°C, and a tan delta value of 0.33 to 0.60 at 130°C. The tan-delta is measured by dynamic mechanical analysis (DMA) using a parallel plate tool at an angular frequency of 10 rad / s.

2. The pressure-sensitive adhesive dispersion polymer according to claim 1, wherein the tan delta value of the pressure-sensitive adhesive dispersion polymer at 130°C is 0.34 to 0.

55.

3. (a) One or more (meth)acrylic monomers individually yield homopolymers having glass transition temperatures (Tg) in the range of -65°C to -40°C, and / or (a) One or more (meth)acrylic monomers are selected from 2-ethylhexyl acrylate, n-butyl acrylate, 3-methylbutyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, propyl acrylate, propylheptyl acrylate, heptadecyl acrylate, decyl methacrylate, dodecyl methacrylate, isodecyl methacrylate, octyl methacrylate, lauryl methacrylate, 2-methoxyethyl acrylate, 3-methoxypropyl acrylate, 3-ethoxypropyl acrylate, 3-methoxybutyl acrylate, hydroxybutyl acrylate, hydroxyethyl caprolactone acrylate, and combinations thereof. The pressure-sensitive adhesive dispersion polymer according to claim 1 or 2.

4. The monomer mixture is (a) One or more (meth)acrylic monomers, and / or, that yield 65 to 95% by weight of homopolymers having a glass transition temperature (Tg) of -40°C or lower. (b) A mixture comprising 5 to 35% by weight of one or more ethylenically unsaturated monomers that yield homopolymers having a Tg of 15°C or higher, Pressure-sensitive adhesive dispersion polymer according to claim 1 or 2: Here, weight percentage is based on the total amount of monomers in the monomer mixture.

5. (b) One or more ethylenically unsaturated monomers individually yield homopolymers having glass transition temperatures (Tg) in the range of 15°C to 150°C, and / or (b) One or more ethylenically unsaturated monomers are selected from acrylonitrile, 3,3,5-trimethylcyclohexyl acrylate, cyclohexyl acrylate, isobornyl acrylate, octadecyl acrylate, tert-butyl acrylate, 2-phenylethyl methacrylate, benzyl methacrylate, n-butyl methacrylate, cyclohexyl methacrylate, ethyl methacrylate, glycidyl methacrylate, hexadecyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, isopropyl methacrylate, methyl methacrylate, neopentyl methacrylate, octadecyl methacrylate, propyl methacrylate, tert-butyl methacrylate, styrene, methoxystyrene, 2-methylstyrene, 3-methylstyrene, 4-ethylstyrene, 4-isopropylstyrene, 4-methoxy-2-methylstyrene, 4-methoxystyrene, 4-methylstyrene, 2-chlorostyrene, 4-bromostyrene, 4-chlorostyrene, 4-fluorostyrene, and combinations thereof. The pressure-sensitive adhesive dispersion polymer according to claim 1 or 2.

6. (c) One or more ethylenically unsaturated monomers having an acidic functional group are selected from ethylenically unsaturated carboxylic acid monomers, ethylenically unsaturated sulfonic acid monomers, and ethylenically unsaturated phosphorus-containing acid monomers. One or more ethylenically unsaturated monomers having a hydroxyl functional group are selected from allyl alcohol, vinyl alcohol, N-methylolacrylamide, 1-penten-3-ol, hydroxyalkyl esters of ethylenically unsaturated acids, and combinations thereof, One or more ethylenically unsaturated monomers having an acidic functional group and a hydroxyl functional group are selected from 3-allyloxy-2-hydroxy-1-propanesulfonic acid, and / or The monomer mixture is (c) comprising 0.2 to 4% by weight of one or more ethylenically unsaturated monomers having acidic functional groups and / or hydroxyl functional groups, Pressure-sensitive adhesive dispersion polymer according to claim 1 or 2: Here, weight percentage is based on the total amount of monomers in the monomer mixture.

7. (d) One or more monomers having at least two ethylenically unsaturated groups are selected from diallyl phthalate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, 1,2-ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and / or combinations thereof. The monomer mixture is (d) A mixture comprising 0 to 0.4% by weight of one or more monomers having at least two ethylenically unsaturated groups, Pressure-sensitive adhesive dispersion polymer according to claim 1 or 2: Here, weight percentage is based on the total amount of monomers in the monomer mixture.

8. (e) The chain transfer agent is selected from n-dodecyl mercaptan, carbon tetrachloride, carbon tetrabromide, bromotrichloromethane, 4-methylbenzenethiol, isooctyl 3-mercaptopropionate, tert-nonyl mercaptan, 4,4'-thiobisbenzenethiol, tert-dodecyl mercaptan, α-methylstyrene dimer, thioglycolic acid, 2-ethylhexyl thioglycolate, butyl 3-mercaptopropionate, 1,8-dimercapto-3,6-dioxaoctane, and / or combinations thereof. The monomer mixture is (e) Containing 0.01 to 0.40% by weight of a chain transfer agent, Pressure-sensitive adhesive dispersion polymer according to claim 1 or 2: Here, weight percentage is based on the total amount of monomers in the monomer mixture.

9. A method for producing a pressure-sensitive adhesive dispersion polymer, A method for producing a dispersed polymer, comprising emulsion polymerization of a monomer mixture: Here, the monomer mixture is (a) One or more (meth)acrylic monomers, each yielding a homopolymer having a glass transition temperature (Tg) of -40°C or lower, in an amount of 60 to 95% by weight. (b) One or more ethylenically unsaturated monomers that yield homopolymers having a Tg of 15°C or higher, in an amount of 5 to 40% by weight. (c) 0.1 to 5% by weight of one or more ethylenically unsaturated monomers having acidic functional groups and / or hydroxyl functional groups. (d) 0 to 0.5% by weight of one or more monomers having at least two ethylenically unsaturated groups, and (e) Containing 0.01 to 0.50% by weight of a chain transfer agent, Monomers (a) to (d) are distinct from each other, and the weight percentage is based on the total amount of monomers in the monomer mixture. The dispersion polymer has a maximum tan delta value in the temperature range of -25°C to -15°C, and the tan delta value at 130°C is 0.33 to 0.

60. The tan-delta is measured by dynamic mechanical analysis (DMA) using a parallel plate tool at an angular frequency of 10 rad / s.

10. The manufacturing method according to claim 9, wherein the tan delta value of the dispersed polymer at 130°C is 0.34 to 0.

55.

11. (a) One or more (meth)acrylic monomers individually yield homopolymers having a glass transition temperature (Tg) in the range of -65°C to -40°C, and / or (a) One or more (meth)acrylic monomers are selected from 2-ethylhexyl acrylate, n-butyl acrylate, 3-methylbutyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, nonyl acrylate, propyl acrylate, propylheptyl acrylate, heptadecyl acrylate, decyl methacrylate, dodecyl methacrylate, isodecyl methacrylate, octyl methacrylate, lauryl methacrylate, 2-methoxyethyl acrylate, 3-methoxypropyl acrylate, 3-ethoxypropyl acrylate, 3-methoxybutyl acrylate, hydroxybutyl acrylate, hydroxyethyl caprolactone acrylate, and / or combinations thereof, and / or (b) One or more ethylenically unsaturated monomers individually yield homopolymers having glass transition temperatures (Tg) in the range of 15°C to 150°C, and / or (b) One or more ethylenically unsaturated monomers are selected from acrylonitrile, 3,3,5-trimethylcyclohexyl acrylate, cyclohexyl acrylate, isobornyl acrylate, octadecyl acrylate, tert-butyl acrylate, 2-phenylethyl methacrylate, benzyl methacrylate, n-butyl methacrylate, cyclohexyl methacrylate, ethyl methacrylate, glycidyl methacrylate, hexadecyl methacrylate, isobornyl methacrylate, isobutyl methacrylate, isopropyl methacrylate, methyl methacrylate, neopentyl methacrylate, octadecyl methacrylate, propyl methacrylate, tert-butyl methacrylate, styrene, methoxystyrene, 2-methylstyrene, 3-methylstyrene, 4-ethylstyrene, 4-isopropylstyrene, 4-methoxy-2-methylstyrene, 4-methoxystyrene, 4-methylstyrene, 2-chlorostyrene, 4-bromostyrene, 4-chlorostyrene, 4-fluorostyrene, and combinations thereof. The manufacturing method according to claim 9 or 10.

12. (c) One or more ethylenically unsaturated monomers having an acidic functional group are selected from ethylenically unsaturated carboxylic acid monomers, ethylenically unsaturated sulfonic acid monomers, and ethylenically unsaturated phosphorus-containing acid monomers. One or more ethylenically unsaturated monomers having a hydroxyl functional group are selected from allyl alcohol, vinyl alcohol, N-methylolacrylamide, 1-penten-3-ol, hydroxyalkyl esters of ethylenically unsaturated acids, and combinations thereof, One or more ethylenically unsaturated monomers having an acidic functional group and a hydroxyl functional group are selected from 3-allyloxy-2-hydroxy-1-propanesulfonic acid, and / or (d) One or more monomers having at least two ethylenically unsaturated groups are selected from diallyl phthalate, allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, 1,2-ethylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, and / or combinations thereof. (e) The chain transfer agent is selected from n-dodecyl mercaptan, carbon tetrachloride, carbon tetrabromide, bromotrichloromethane, 4-methylbenzenethiol, isooctyl 3-mercaptopropionate, tert-nonyl mercaptan, 4,4'-thiobisbenzenethiol, tert-dodecyl mercaptan, α-methylstyrene dimer, thioglycolic acid, 2-ethylhexyl thioglycolate, butyl 3-mercaptopropionate, 1,8-dimercapto-3,6-dioxaoctane, and combinations thereof. The manufacturing method according to claim 9 or 10.

13. Use of a pressure-sensitive adhesive dispersion polymer according to claim 1 or 2, or a pressure-sensitive adhesive dispersion polymer obtained by the manufacturing method according to claim 9 or 10, for the production of a pressure-sensitive adhesive.

14. A pressure-sensitive adhesive composition comprising a pressure-sensitive adhesive dispersion polymer according to claim 1 or 2, or a pressure-sensitive adhesive dispersion polymer obtained by a manufacturing method according to claim 9 or 10.

15. Use of the pressure-sensitive adhesive composition according to claim 14 for the manufacture of a pressure-sensitive adhesive sheet.

16. A pressure-sensitive adhesive sheet comprising a support substrate having one surface coated with the pressure-sensitive adhesive composition according to claim 14.

17. Use of the pressure-sensitive adhesive sheet according to claim 16 for labeling articles and / or for stationery tape and / or double-sided tape.

18. Use of a dispersed polymer having a maximum tan delta value in the temperature range of -25°C to -15°C and a tan delta value of 0.33 to 0.60 at 130°C for the manufacture of pressure-sensitive adhesives: Here, the tan-delta is measured by dynamic mechanical analysis (DMA) using a parallel plate tool at an angular frequency of 10 rad / s.