Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J175/00—Adhesives based on polyureas or polyurethanes; Adhesives based on derivatives of such polymers
  • C09J175/04—Polyurethanes
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
  • C09J11/02—Non-macromolecular additives
  • C09J11/06—Non-macromolecular additives organic
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J7/00—Adhesives in the form of films or foils
  • C09J7/20—Adhesives in the form of films or foils characterised by their carriers

Definitions

• This invention relates to the adhesive composition from which the adhesive sheet excellent in oleic acid resistance is obtained.
• Adhesives are widely used in various fields such as manufacturing scenes of various products including electronic devices and automobiles, and medical products represented by surgical tape.
• Examples of the pressure-sensitive adhesive composition for improving the oleic acid resistance include, for example, 50 to 90% by mass of a (meth) acrylic acid alkyl ester having an alkyl group having 4 to 12 carbon atoms, and a carboxyl group-containing monomer 3 to 20 It contains 3 to 20% by mass of a hydroxyl group-containing monomer and 3 to 15% by mass of a (meth) acrylic acid alkyl ester having an alkyl group having 1 to 3 carbon atoms and has a weight average molecular weight of 700,000 to
• a pressure-sensitive adhesive composition containing 2 million, an acrylic copolymer having a hydroxyl group and a carboxyl group having a theoretical Tg of ⁇ 40 ° C. or less and a crosslinking agent is disclosed (see, for example, Patent Document 1) .)
• the problem to be solved by the present invention is to provide a pressure-sensitive adhesive composition capable of obtaining a pressure-sensitive adhesive sheet having excellent resistance to oleic acid with little decrease in adhesive strength even when contacted with oleic acid for a long time.
• the present invention is a reaction product of polycarbonate polyol (a1), polyisocyanate (a2) and chain extender (a3), and a urethane resin having a hydroxyl group having a weight average molecular weight in the range of 5,000 to 40,000 (A pressure-sensitive adhesive composition containing A), a crosslinking agent (B), and an organic solvent (C), and a pressure-sensitive adhesive sheet characterized by having a dry film thereof. .
• the pressure-sensitive adhesive composition of the present invention has good coatability, and the resulting pressure-sensitive adhesive sheet has a good initial adhesive force due to crosslinking, and there is little decrease in the adhesive strength even when contacted with oleic acid for a long time. Excellent oleic acid resistance.
• the pressure-sensitive adhesive composition of the present invention is a double-sided tape used for bonding a casing constituting a portable electronic terminal, a tablet personal computer, etc., a label for imparting designability to the surface of the casing, a waterproof tape, and a clothing It can be suitably used in various fields such as an adhesive tape.
• the pressure-sensitive adhesive composition of the present invention is a reaction product of polycarbonate polyol (a1), polyisocyanate (a2) and chain extender (a3), and has a weight average molecular weight in the range of 5,000 to 40,000.
• the urethane resin (A) having a hydroxyl group, a crosslinking agent (B), and an organic solvent (C) are contained as essential components.
• the polycarbonate polyol (a1) is an essential component for obtaining excellent oleic acid resistance. Unlike an ether structure or an ester structure, a carbonate structure hardly swells or decomposes even when contacted with oleic acid, and can suppress a decrease in adhesive strength.
• As said polycarbonate polyol (a1) what was obtained by making carbonate ester and / or phosgene react with the compound which has a 2 or more hydroxyl group by a well-known method can be used, for example.
• carbonate ester for example, methyl carbonate, dimethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate and the like can be used. These compounds may be used alone or in combination of two or more.
• Examples of the compound having two or more hydroxyl groups include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1, 3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10 -Decanediol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethylpropanoldiol, neopentyl glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, polyethylene glycol, polypropylene glycol, Polytetra Ji glycol, polyhexamethylene adipate
• the obtained polycarbonate polyol can be made into a liquid and the glass transition temperature of the urethane resin (A) can be lowered, so that excellent adhesive strength (particularly initial adhesive strength) can be obtained, and good adhesive strength and olein resistance can be obtained.
• adhesive strength particularly initial adhesive strength
• olein resistance good adhesive strength and olein resistance
• the number average molecular weight of the polycarbonate polyol (a1) is preferably in the range of 700 to 5,000, more preferably in the range of 800 to 3,000, from the viewpoint that adhesion strength and oleic acid resistance can be maintained at a high level. Preferably there is.
• the number average molecular weight of the said polycarbonate polyol (a1) shows the value measured on condition of the following by the gel permeation chromatography (GPC) method.
• Measuring device High-speed GPC device (“HLC-8220GPC” manufactured by Tosoh Corporation) Column: The following columns manufactured by Tosoh Corporation were connected in series. "TSKgel G5000" (7.8 mm ID x 30 cm) x 1 "TSKgel G4000” (7.8 mm ID x 30 cm) x 1 "TSKgel G3000” (7.8 mm ID x 30 cm) x 1 “TSKgel G2000” (7.8 mm ID ⁇ 30 cm) ⁇ 1 detector: RI (differential refractometer) Column temperature: 40 ° C Eluent: Tetrahydrofuran (THF) Flow rate: 1.0 mL / min Injection amount: 100 ⁇ L (tetrahydrofuran solution with a sample concentration of 0.4 mass%) Standard sample: A calibration curve was prepared using the following standard polystyrene.
• the polycarbonate polyol (a1) may be used in combination with other polyols as necessary.
• polyether polyol for example, polyether polyol, polyester polyol, polybutadiene polyol, polycaprolactone polyol, acrylic polyol, dimer diol, polyisoprene polyol and the like can be used. These polyols may be used alone or in combination of two or more.
• polyisocyanate (a2) examples include aromatic polyisocyanates such as xylylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, and naphthalene diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, 4,4 ′.
• aromatic polyisocyanates such as xylylene diisocyanate, phenylene diisocyanate, diphenylmethane diisocyanate, toluene diisocyanate, and naphthalene diisocyanate
• hexamethylene diisocyanate lysine diisocyanate
• cyclohexane diisocyanate isophorone diisocyanate
• -Aliphatic or alicyclic polyisocyanates such as dicyclohexylmethane diisocyanate, diisocyanate methylcyclohexane, tetramethylxylylene diisocyanate and the like can be used.
• These polyisocyanates may be used alone or in combination of two or more.
• aromatic polyisocyanate from the viewpoint that swelling and decomposition hardly occur even when contacted with oleic acid, and oleic acid resistance can be further improved, and it is more preferable to use diphenylmethane diisocyanate and / or toluene diisocyanate. preferable.
• the chain extender is used for adjusting the adhesive force, and for example, one having a number average molecular weight in the range of 50 to 400 can be used.
• ethylene glycol, diethylene recall, triethylene glycol, propylene Aliphatic polyol compounds such as glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, saccharose, methylene glycol, glycerin, sorbitol; bisphenol A, 4,4′- Aromatic polyol compounds such as dihydroxydiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenylsulfone, hydrogenated bisphenol A, hydroquinone, etc .; water; ethylenediamine, 1,2-propanediamine, 1,6-hexame Range amine, piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,
• chain extenders may be used alone or in combination of two or more.
• an aliphatic polyol compound from the viewpoint of suppressing discoloration over time, and by using a relatively short chain extender as a hard segment, excellent cohesive force can be obtained, and adhesive strength can be further improved. Therefore, it is more preferable to use 1,4-butanediol and / or ethylene glycol.
• the urethane resin (A) is cross-linked with a cross-linking agent (B) described later, and has a hydroxyl group for obtaining a good initial adhesive force, preferably 2 or more, more preferably in the range of 2 to 4 It has a hydroxyl group.
• the polyol composition containing the said polycarbonate polyol (a1) with respect to the molar ratio of the isocyanate group which the said polyisocyanate (a2) has, and the said chain extender (a3) are, for example.
• the method of making it react so that the total molar ratio with the hydroxyl group and amino group which it has may become excess is mentioned.
• the polycarbonate polyol (a1) and the chain extender (a3) may be charged all at once or may be charged in two or more times while controlling the reaction.
• a molar ratio (NCO / OH + NH) of the total of the hydroxyl group and amino group of the polyol composition containing the polycarbonate polyol (a1) and the chain extender (a3) and the isocyanate group of the polyisocyanate (a2) Is preferably in the range of 0.3 to 0.99 from the viewpoint that the reaction can be easily controlled and a good initial adhesive force can be obtained by the crosslinking property with the crosslinking agent (B) described later. A range of 0.9 is more preferred.
• an alcohol solvent such as methanol or 1,3-butanediol may be added for the purpose of deactivating the remaining isocyanate groups.
• the weight average molecular weight of the urethane resin (A) obtained by the above method must be in the range of 5,000 to 40,000.
• the weight average molecular weight of the urethane resin (A) is preferably in the range of 7,000 to 35,000 from the viewpoints of olein resistance and adhesive strength.
• the number average molecular weight of the urethane resin (A) is preferably in the range of 3,000 to 20,000 from the viewpoint of further improving the coating property, initial adhesive strength and oleic acid resistance. More preferably, it is in the range of 10,000 to 10,000.
• the weight average molecular weight and number average molecular weight of the said urethane resin (A) show the value obtained by measuring similarly to the number average molecular weight of the said polycarbonate polyol (a1).
• crosslinking agent (B) for example, a known polyisocyanate crosslinking agent, epoxy crosslinking agent, melamine crosslinking agent and the like can be used. These crosslinking agents may be used alone or in combination of two or more. Among these, it is preferable to use a polyisocyanate crosslinking agent from the viewpoint that it exhibits good crosslinkability with the hydroxyl group of the urethane resin (A), and further excellent initial adhesive force and oleic acid resistance can be obtained.
• polyisocyanate crosslinking agent examples include the same polyisocyanate as the polyisocyanate (a2); a compound obtained by reacting the polyisocyanate compound with a polyhydric alcohol such as trimethylolpropane and pentaerythritol; Isocyanurate compounds; burette compounds of the polyisocyanate compounds; adducts thereof; urethane diisocyanate compounds obtained by reacting the polyisocyanates and polyols, and the like can be used.
• These polyisocyanate crosslinking agents may be used alone or in combination of two or more.
• the amount of the crosslinking agent (B) used is in the range of 0.01 to 10 parts by mass with respect to 100 parts by mass of the urethane resin (A) in terms of obtaining good initial adhesive strength and oleic acid resistance.
• the range of 0.1 to 5 parts by mass is more preferable.
• organic solvent (C) examples include ester solvents such as ethyl acetate, methyl acetate, and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; and aliphatic hydrocarbons such as heptane, hexane, cyclohexane, and methylcyclohexane. Solvent; aromatic hydrocarbon solvents such as toluene, o-xylene, m-xylene, and p-xylene can be used. These organic solvents may be used alone or in combination of two or more.
• the amount of the organic solvent (C) used is preferably in the range of 20 to 80% by mass, more preferably in the range of 30 to 70% by mass in the pressure-sensitive adhesive composition, from the viewpoint of coating properties and drying properties. .
• the pressure-sensitive adhesive composition of the present invention contains the components (A) to (C) as essential components, but may further contain other additives as necessary.
• additives examples include rust preventives, thixotropic agents, dispersants, sensitizers, urethanization catalysts, polymerization inhibitors, leveling agents, tackifiers, foam stabilizers, and the like. These additives may be used alone or in combination of two or more.
• the method of manufacturing the adhesive sheet which has is mentioned.
• the substrate examples include polyesters such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polyolefin, polyacrylate, polyvinyl chloride, polyethylene, polypropylene ethylene vinyl alcohol, polyurethane, polyamide, and polyimide. Sheet or film; glass or the like can be used.
• the surface of these base materials may be subjected to mold release treatment, antistatic treatment, corona treatment and the like.
• the thickness of the substrate is determined according to the application for which the pressure-sensitive adhesive sheet is used, and is, for example, in the range of 10 to 100 ⁇ m.
• Examples of the method of applying the pressure-sensitive adhesive composition to the substrate include a method using an applicator, roll coater, gravure coater, reverse coater, spray coater, air knife coater, die coater, and the like.
• the thickness of the coated adhesive composition after drying is determined according to the use for which the adhesive sheet is used, and is, for example, in the range of 5 to 100 ⁇ m.
• Examples of the method of drying the pressure-sensitive adhesive composition after coating the pressure-sensitive adhesive composition on the substrate include a method of drying at 50 to 120 ° C. for 30 seconds to 10 minutes. Further, after the drying, further aging may be performed in the range of 30 ° C. to 50 ° C. in order to accelerate the curing reaction.
• the gel fraction when the dried film is immersed in toluene for 24 hours is preferably in the range of 10 to 60% by mass from the viewpoint of obtaining good adhesive strength (particularly initial adhesive strength). A range of ⁇ 50 mass% is more preferred.
• the initial adhesive strength of the adhesive tape is preferably in the range of 2 to 10 N / 5 mm, more preferably in the range of 2.5 to 8 N / 5 mm.
• the measuring method of the initial adhesive force of the said adhesive tape is described in the Example mentioned later.
• the pressure-sensitive adhesive composition of the present invention has good coatability, and the resulting pressure-sensitive adhesive sheet has a good initial adhesive force due to crosslinking, and the adhesive strength is reduced even when contacted with oleic acid for a long time. Is excellent in oleic acid resistance.
• the pressure-sensitive adhesive composition of the present invention comprises a double-sided tape used for bonding a casing constituting a portable electronic terminal, a tablet personal computer, etc., a label for imparting designability to the surface of the casing, a waterproof tape, a medical use It can be suitably used in various fields such as an adhesive tape.
• a urethane resin (A-2) having 2,850 mPa ⁇ s and a weight average molecular weight of 8,200 was obtained.
• Example 1 1.2 parts by mass of an isocyanurate compound of hexamethylene diisocyanate (hereinafter abbreviated as “HDI nurate”) with respect to 100 parts by mass of the urethane resin (A-1) obtained in Synthesis Example 1. 1 part by mass (“T-81E” manufactured by DIC Corporation) was added to obtain an adhesive composition.
• the pressure-sensitive adhesive composition was applied to the surface of a 38 ⁇ m-thick polyethylene terephthalate (PET) film that had been release-treated on the surface so that the film thickness after drying was 20 ⁇ m, and further at 100 ° C. for 2 minutes. The film was dried at 120 degrees for 1 minute to obtain a dry film. Then, the said dry film was bonded on both surfaces of 12-micrometer-thick PET film, and the adhesive sheet was obtained by making it age at 40 degreeC for 3 days.
• PET polyethylene terephthalate
• Example 2 A pressure-sensitive adhesive sheet was obtained in the same manner as in Example 1 except that the types / and / or amounts of the urethane resin (A) and the crosslinking agent (B) used were changed as shown in Table 1.
• a urethane resin (A′-1) having 1,360 mPa ⁇ s and a weight average molecular weight of 4,000 was obtained.
• a urethane resin (A′-2) having a weight average molecular weight of 42,100 mPa ⁇ s and 60,000 was obtained.
• the 180 degree peel strength was measured in an atmosphere of 23 ° C. and 50% humidity in accordance with JIS K6848-1974, and the adhesive strength after the oleic acid resistance test ( N / 10 mm).
• the oleic acid resistance was evaluated by the difference between the initial adhesive strength and the adhesive strength after the oleic acid resistance test.
• D-101 hexamethylene diisocyanate-based bifunctional polyurethane diisocyanate
• Duranate D-101 manufactured by Asahi Kasei Chemicals Corporation
• the pressure-sensitive adhesive sheet obtained from the pressure-sensitive adhesive composition of the present invention showed little decrease in adhesion even after being immersed in oleic acid for 2 days.
• Comparative Example 1 is an embodiment in which the weight average molecular weight of the urethane resin (A) is below the range specified in the present invention, but the adhesive was dissolved in oleic acid, and the adhesive sheet was peeled off from the adherend. Further, due to the low viscosity, repelling occurred during film coating, and it was difficult to obtain a uniform dry film.
• Comparative Example 2 is an embodiment in which the weight average molecular weight of the urethane resin (A) exceeds the range specified in the present invention, but a uniform dry film having a high viscosity was not obtained.
• Comparative Example 3 is an embodiment using polyether polyol instead of polycarbonate polyol (a1), but the adhesive was dissolved in oleic acid, and the adhesive sheet was peeled off from the adherend.
• Comparative Example 4 is an embodiment in which the cross-linking agent (B) is not used, but the adhesive was dissolved in oleic acid and swelled and decomposed after being immersed in oleic acid for 2 days.
• Comparative Examples 5 to 7 all use an acrylic resin-based pressure-sensitive adhesive composition, but after being immersed in oleic acid for 2 days, they were swollen and decomposed.

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• Polyurethanes Or Polyureas (AREA)
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• 2015
  • 2015-09-29 WO PCT/JP2015/077473 patent/WO2016063685A1/ja active Application Filing
  • 2015-09-29 CN CN201580056798.4A patent/CN107075336B/zh active Active
  • 2015-09-29 KR KR1020177013344A patent/KR102335832B1/ko active IP Right Grant
  • 2015-09-29 JP JP2016504827A patent/JP5935962B1/ja active Active
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