JP2000328034A - Polyurethane / urea adhesive composition and coated product thereof - Google Patents

Abstract

(57) [Summary] [Problem] Since polyolefin film is non-polar, it has been extremely difficult to improve the adhesiveness to the film. Usually, chlorinated polyolefin, modified polyethylene or the like has been added, or the surface of the polyolefin film has been modified by corona discharge treatment, plasma treatment or the like. However, the tack was still insufficient. An object of the present invention is to provide a polyurethane / urea pressure-sensitive adhesive composition having sufficient adhesion and removability to a polyolefin film, and a coated article using the composition. A polyurethane / urea pressure-sensitive adhesive composition comprising a polyurethane / urea resin (A) obtained from a polyol, an organic polyisocyanate, and a chain extender.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane / urea pressure-sensitive adhesive composition having a urethane group and a urea group, which exhibits sufficient adhesion to non-polar films such as polyolefin films, and to a method for using the same. Related to coatings

[0002]

2. Description of the Related Art Conventionally used pressure-sensitive adhesives cannot provide a sufficient adhesive force as they are, particularly because they have a non-polar surface with respect to polyolefin films. Therefore, chlorinated polyolefin, modified polyethylene, etc. are usually added to the adhesive, or the surface of the polyolefin film is modified by corona discharge treatment, plasma treatment, solution treatment, etc. to improve the adhesiveness. Was.

[0003]

The coated materials such as tapes, labels, seals, films and sheets using the conventional pressure-sensitive adhesives have excellent adhesiveness to polar films, but are not suitable for non-polar films. On the other hand, adhesiveness and removability were not sufficient.

The present invention provides a polyurethane / urea pressure-sensitive adhesive composition exhibiting sufficient adhesiveness to a polyolefin film and having excellent removability, and a coated article using the pressure-sensitive adhesive composition. is there.

[0005]

Heretofore, conventionally, the adherend, such as polyolefin film, has often been modified by corona discharge treatment, plasma treatment, solution treatment, or the like. On such a modified surface, a hydrophilic group was formed on the surface to exhibit tackiness due to the interaction with the pressure-sensitive adhesive. However, the tackiness itself was low, and there was a problem in practical use.

In the present invention, it has been found that a polyurethane / urea pressure-sensitive adhesive having a urethane group and a urea group is provided on a polyolefin film having such a surface to further increase the tackiness and to achieve practical tackiness.

That is, the first invention relates to a polyurethane / urea pressure-sensitive adhesive composition comprising a polyurethane / urea resin (A) obtained from a polyol, an organic polyisocyanate, and a chain extender.

The second invention relates to the polyurethane / urea pressure-sensitive adhesive composition according to the first invention, wherein the polyurethane / urea resin (A) has a hydrazine residue.

The third invention relates to the polyurethane / urea pressure-sensitive adhesive composition according to the first invention, wherein the polyurethane / urea resin (A) is an aqueous resin.

The fourth invention is characterized in that a polyfunctional compound selected from the group consisting of a polyisocyanate, a polycarbodiimide and an epoxy compound is blended with the polyurethane / urea resin (A).
The present invention relates to a urea pressure-sensitive adhesive composition.

The fifth invention relates to a coated polyurethane / urea pressure-sensitive adhesive composition according to any one of the first to fourth inventions, characterized in that a polyolefin film or a sheet is used as an adherend.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The polyol used in the present invention includes:
Examples include polyester polyols and polyether polyols. Known polyester polyols are used as the polyester polyol.

Terephthalic acid, adipic acid,
Azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, trimellitic acid and the like are mentioned, and as glycol components ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, 1,6-hexane glycol, 3-methyl-1,5-methyl glycol Pentanediol, 3,3′-dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol,
1,4-butanediol, neopentyl glycol, butylethylpentanediol, and glycerin, trimethylolpropane, pentaerythritol, and the like as the polyol component.

In addition, polycaprolactone, poly (β-
And polyester polyols obtained by ring-opening polymerization of lactones such as methyl-γ-valerolactone) and polyvalerolactone.

The molecular weight of the polyester polyol can be used from a low molecular weight to a high molecular weight. Preferably, the polyester polyol having a molecular weight of 1,000 to 5,000 and having two or more functional groups is a polyol constituting the polyurethane / urea resin (A). It is preferable to use 1 to 50 mol% of them.

As the polyether polyol used in the present invention, a known polyether polyol is used. For example, propylene glycol, ethylene glycol, glycerin, using a low molecular weight polyol such as trimethylolpropane as an initiator, ethylene oxide, propylene oxide, butylene oxide, polyether polyol obtained by polymerizing an oxirane compound such as tetrahydrofuran, specifically Specifically, those having two or more functional groups, such as polypropylene glycol, polyethylene glycol, and polytetramethylene glycol, are used. The molecular weight of the polyether polyol can be used from a low molecular weight to a high molecular weight, but preferably the molecular weight is 1,
It is preferable to use a polyether polyol having a molecular weight of 2,000 to 5,000 and having two or more functional groups in an amount of 1 to 80 mol% in the polyol constituting the polyurethane / urea (A).

In the present invention, trifunctional or higher functional polyols can also be used. In that case, the molecular weight is preferably from 2,000 to 4,000. When the molecular weight is 2,000 or less, the reactivity becomes high, and gelation is easily caused. If the molecular weight is 4,000 or more, the reactivity of the polyol becomes poor, and the cohesive force of the urethane pressure-sensitive adhesive decreases. Further, if necessary, polyols having a small molecular weight such as ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerin, trimethylolpropane, and pentaerythritol may also be used. Can be used.

Examples of the organic polyisocyanate compound used in the present invention include known aromatic polyisocyanates, aliphatic polyisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates.

As aromatic polyisocyanates, 1,3
-Phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate,
2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4′-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,
Examples thereof include 3,5-triisocyanatebenzene, dianisidine diisocyanate, 4,4'-diphenylether diisocyanate, and 4,4 ', 4 "-triphenylmethane triisocyanate.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, Examples include 2,4,4-trimethylhexamethylene diisocyanate.

As the araliphatic polyisocyanates, ω, ω′-diisocyanate-1,3-dimethylbenzene, ω, ω′-diisocyanate-1,4-dimethylbenzene, ω, ω′-diisocyanate-1,4-diethylbenzene , 1,4-tetramethylxylylene diisocyanate, 1,3-tetramethyl xylylene diisocyanate, and the like.

As the alicyclic polyisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, methyl-2 , 4-cyclohexanediisocyanate, methyl-
2,6-cyclohexane diisocyanate, 4,4'-
Methylene bis (cyclohexyl isocyanate), 1,
4-bis (isocyanatomethyl) cyclohexane,
1,4-bis (isocyanatomethyl) cyclohexane and the like can be mentioned.

Further, in the present invention, a trimethylolpropane adduct of the above-mentioned polyisocyanate, a burette having reacted with water, a trimer having an isocyanurate ring, and the like can also be used in combination.

The polyisocyanate used in the present invention is preferably 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate).

In the present invention, a urea bond can be introduced by using an amine-based or hydrazide-based chain extender. As amine chain extenders, ethylenediamine, propylenediamine, hexamethylenediamine, diphenyldiamine,
There are polyamines such as isophoronediamine and xylylenediamine. If necessary, a monoamine can also be used as a reaction terminator.

The introduction of a hydrazide group into the polyurethane / urea resin can be achieved by using a chain extender having two hydrazide groups in the molecule or a reaction terminator having one hydrazide group. As the chain extender, malonic dihydrazide which is a dehydration condensate of dicarboxylic acid and hydrazine, succinic dihydrazide, glutaric dihydrazide, adipic dihydrazide, sebacic dihydrazide, maleic dihydrazide, fumaric dihydrazide,
Dicarboxylic acid dihydrazide such as itaconic acid dihydrazide;

Other aliphatic dihydrazide compounds include ethylene-1,2-dihydrazine and propylene-1,3.
-Dihydrazine, butylene-1,4-dihydrazine and the like.

Examples of the monohydrazine compound as a reaction terminator include alkylhydrazines such as monomethylhydrazine, 1,1-dimethylhydrazine, isopropylhydrazine, t-butylhydrazine, and aromatic benzylhydrazine.

As the catalyst used in the present invention, a known catalyst can be used. For example, tertiary amine compounds, organometallic compounds, and the like.

Examples of the tertiary amine compound include triethylamine, triethylenediamine, 1,8-diazabicyclo (5,4,0) -undecene-7 (DBU) and the like.

Examples of the organometallic compound include a tin compound and a non-tin compound.

As the tin compound, dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide,
Dibutyltin dimaleate, dibutyltin dilaurate (D
BTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, tributyltin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, 2-ethylhexanoic acid Tin etc. are mentioned.

Examples of the non-tin compounds include titanium compounds such as dibutyl titanium dichloride, tetrabutyl titanate and butoxy titanium trichloride, and lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate and lead naphthenate. Iron, such as iron, 2-ethylhexanoate and iron acetylacetonate; cobalt, such as cobalt benzoate and cobalt 2-ethylhexanoate; zinc, such as zinc naphthenate and zinc 2-ethylhexanoate; zirconium naphthenate And the like.

The polyurethane / urea resin (A) can be produced based on a known method. A polyol and an organic polyisocyanate form a prepolymer with an NCO / OH ratio of 1.1 to 1.9, and an amine compound, a hydrazide compound,
Alternatively, it can be obtained by extending the chain by using both together.

As the solvent used for the synthesis, known solvents can be used. Examples include methyl ethyl ketone, ethyl acetate, toluene, xylene, acetone and the like. Ethyl acetate and toluene are particularly preferred from the viewpoint of the solubility of the polyurethane / urea resin (A) and the boiling point of the solvent.

The polyurethane / urea resin (A) of the present invention
Is preferably 100 ° C. or lower in the prepolymerization reaction, and 50 ° C. or lower in the chain extension reaction.

The polyurethane / urea resin (A) constituting the present invention can be used not only as an oily but also as an aqueous resin.

As the method, 1) a method of using a diol containing a carboxyl group as a diol component and neutralizing with a base, 2) a method of prepolymerizing with an alkyl dialkanolamine having a tertiary amino group, and a method of quaternizing; 3) a method of prepolymerizing with an alkyl dialkanolamine having a tertiary amino group, neutralizing with an acid to form an amine salt,
4) A method in which a polyol having high water solubility, for example, polyethylene glycol is used as a urethane component. As the pressure-sensitive adhesive, 1) and 4) are preferable.

In the present invention, a polyfunctional compound may be used. Examples of the polyfunctional compound include a polyisocyanate such as a trimethylolpropane adduct of an isocyanate compound, a burette that has been reacted with water, or a trimer having an isocyanurate ring; polycarbodiimide obtained by decarboxylation of isophorone diisocyanate and xylylene diisocyanate. Compound; an epoxy compound having two or more oxirane rings. These polyfunctional compounds are used in an amount of 1 to 20 parts based on 100 parts (parts by weight) of the polyurethane / urea resin (A). If it is 1 part or less, the cohesive strength decreases, and if it is 20 parts or more, the adhesive strength decreases. Preferably it is 2 to 10 parts.

The polyurethane / urea pressure-sensitive adhesive according to the present invention may contain, if necessary, a filler such as talc, calcium carbonate, and titanium oxide, a tackifier, a coloring agent, an ultraviolet absorber, an antioxidant, an antifoaming agent, and a light. An additive such as a stabilizer may be blended.

The polyurethane / urea pressure-sensitive adhesive composition according to the present invention is used by being applied to a substrate such as a plastic film, a plastic sheet, polyurethane, paper, or polyurethane foam. The coated product is suitably used as a tape, a label, a seal, a sheet, and the like. In particular, it shows good adhesiveness and removability to polyolefin films. As the polyolefin film, a polyolefin-based resin having a film thickness of 10 to 1000 μm obtained by molding into a film by various molding methods, for example, a T-die method, a calendar method, a casting method, an inflation method, or the like is used. Can be

Specific examples of the polyolefin resin include:
There are polyethylene, polypropylene, polybutene, and ethylene / propylene copolymer. Eventually, the film may be uniaxially or biaxially stretched in the stretching step. Corona treatment and plasma treatment improve the adhesion to polyolefins with polar groups introduced on the surface.

The synthesis examples of the polyurethane / urea resin and the polyurethane resin and acrylic resin used for comparison are described below.

Synthesis Example 1 Polyester polyol P-2 was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel.
010 (bifunctional polyester polyol, OH value 56,
249 g of hexamethylene diisocyanate (manufactured by Sumitomo Bayer KK), 300 g of toluene, and 0.04 of iron 2-ethylhexanoate as a catalyst
g, the temperature is gradually raised to 90 ° C., and the reaction is carried out for 3 hours. Next, the mixture was cooled to 30 ° C., 17 g of isophoronediamine (manufactured by Huls Japan KK) was added, and the mixture was aged at the same temperature for 1 hour. The reaction solution is transparent and has a solid content of 50%.
%, MN (number average molecular weight) of 11,000, and MW (weight average molecular weight) of 35,000.

Synthesis Example 2 Polyether polyol PP was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet, a thermometer, and a dropping funnel.
2000 (bifunctional polyether polyol, OH value 5
6, Sanyo Chemical Co., Ltd.) 240 g, isophorone diisocyanate (Huls Japan K.K.) 43 g,
300 g of toluene and 0.04 g of iron 2-ethylhexanoate as a catalyst are charged, and the temperature is gradually raised to 90 ° C. to carry out a reaction for 3 hours. Next, the mixture was cooled to 30 ° C., 17 g of isophoronediamine was added, and the mixture was aged at the same temperature for 1 hour. This reaction solution is transparent and has a solid content of 50%, MN (number average molecular weight).
9,500 and MW (weight average molecular weight) of 33,000.

Synthesis Example 3 Polyether polyol PP was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet, a thermometer, and a dropping funnel.
2000 (bifunctional polyether polyol, OH value 5
6, Sanyo Chemical Co., Ltd.) 240 g, isophorone diisocyanate (Huls Japan K.K.) 43 g,
300 g of toluene and 0.04 g of iron 2-ethylhexanoate as a catalyst are charged, and the temperature is gradually raised to 90 ° C. to carry out a reaction for 3 hours. Next, the mixture was cooled to 30 ° C., 17 g of adipic dihydrazide was added, and the mixture was aged at the same temperature for 1 hour. This reaction solution was transparent and had a solid content of 50%, MN (number average molecular weight) of 12,000, and MW (weight average molecular weight) of 40,00.
It was 0.

Synthesis Example 4 Polyether polyol PP was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel.
2000 (bifunctional polyether polyol, OH value 5
6, Sanyo Chemical Co., Ltd.) 135 g, PEG2000
(OH value 56, manufactured by NOF CORPORATION) 18 g, dimethylolbutanoic acid (Mitsubishi Chemical Corporation) 26 g, isophorone diisocyanate (manufactured by Huls Japan K.K.) 9
1 g, 300 g of ethyl acetate, and 0.05 g of iron 2-ethylhexanoate were charged as a catalyst, and the temperature was gradually raised to 90 ° C. to carry out a reaction for 3 hours. Next, it cooled to 30 degreeC, added 30 g of isophorone diamines, and aged at the same temperature for 1 hour. Next, 12 g of ammonia water and 330 g of distilled water were added to remove the solvent. This reaction solution is transparent and has a solid content of 48.
%, MN (number average molecular weight) of 11,000, and MW (weight average molecular weight) of 34,000.

Synthesis Example 5 Polyester polyol P-2 was placed in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel.
010 (bifunctional polyester polyol, OH value 56,
275 g of isophorone diisocyanate (manufactured by Huls Japan KK), 300 g of toluene, 0.02 g of iron 2-ethylhexanoate as a catalyst
4 g is charged, the temperature is gradually raised to 90 ° C., and the reaction is carried out for 3 hours. This reaction solution was transparent and had a solid content of 50%, MN (number average molecular weight) of 11,000, MW (weight average molecular weight) of 37,
000.

Synthesis Example 6 135 g of butyl acrylate, 150 g of 2-ethylhexyl acrylate, 15 g of 2-hydroxyethyl acrylate, 300 g of ethyl acetate and 300 g of benzoyl peroxide were placed in a four-necked flask equipped with a stirrer, a nitrogen inlet tube, a thermometer and a dropping funnel. The solution consisting of 0.7 g was put into a reactor equipped with a reflux condenser and reacted at about 80 ° C. for 4 hours under a nitrogen gas stream. This solution was colorless and transparent, had a solid content of 50%, MN (number average molecular weight) of 113,000, and MW (weight average molecular weight) of 44.
It was 0000.

[0050]

EXAMPLES Examples and comparative examples will be described below.

Table 1 shows the composition of the polyurethane pressure-sensitive adhesive.

Table 2 shows the results of the OPP adhesiveness, adhesive strength, and holding power test.

Table 3 shows the results of the ball tack test and the removability test.

The test items are as follows.

Coating method: The above-mentioned pressure-sensitive adhesive solution is applied to release paper so that a dry coating film becomes 25 μm, dried at 100 ° C. for 2 minutes, and a coated material is prepared using a PET sheet. After aging at room temperature for one week, physical properties were measured.

OPP Adhesion: The adhesive sheet was adhered to the OPP film by finger pressure, peeled off, and the adhesion was evaluated. Adhesion was fairly strong, か な り was sticky, 僅 か was slight, and × was not.

Adhesive force: Adhesive sheet was adhered to a stainless steel plate (SUS304) having a thickness of 2 mm at 23 ° C. and 65% RH, roll-pressed in accordance with JIS, and after 20 minutes, peel strength was measured with a shopper type peel tester. (180 degree peel, pulling speed 300 mm / min) was measured. Holding force: A 2 mm thick stainless steel plate (SU
S304) and bonded together as an area of 25 mm x 25 mm,
Roll pressure bonding is performed according to JIS, and after standing at 40 ° C. for 20 minutes, a load of 1 kg is applied.
The shift after 0 minutes was measured.

Ball tack: J. It was measured under the conditions of 23 ° C. and 65% RH by the Dow rolling ball method.

Peelability: A pressure sensitive adhesive sheet was formed on a stainless steel plate (SU
S304) After adhering to a glass plate, 40 ° C., 65% R
It was left under the condition of H, cooled to 23 ° C. and 65% RH, then peeled off, and the adhesive residue was visually evaluated. After peeling, ◎ indicates no adhesive transfer to the adherend, ○ indicates extremely slight transfer, △ indicates partial transfer, and X indicates complete transfer.

[0060]

[Table 1]

The composition is as follows: polyurethane / urea resin (A)
4 g of the polyfunctional compound was added to 100 g. V-04: Carbodiimide compound (manufactured by Nisshinbo Co., Ltd.), Takenate D-160N: hexamethylene diisocyanate trimethylolpropane adduct (manufactured by Takeda Pharmaceutical Co., Ltd.)

[0062]

[Table 2]

[0063]

[Table 3]

Substrate: PET (polyethylene terephthalate) film thickness: 25 μN C. : Non-creep * S. D. : Slip down From the above results, the polyurethane / urea pressure-sensitive adhesive composition according to the present invention has good adhesion to polyolefin film and excellent removability. In particular, it can be seen that those using a hydrazide compound are excellent in polyolefin adhesiveness.

[0065]

The polyurethane / urea pressure-sensitive adhesive composition of the present invention exhibits good adhesion and removability to polyolefin films. Further, a coated product having less adhesive residue than an acrylic pressure-sensitive adhesive can be obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J004 AA14 AB01 AB05 CA03 CA04 CA06 CC02 GA01 4J040 EF061 EF111 EF131 EF151 EF291 EF301 EF311 EF321 GA22 HA126 JA02 JA03 JA08 JB02 JB09 KA23 LA06 MA09 MA10 MA11 MB03 PA42

Claims (5)

[Claims] 1. A polyurethane / urea pressure-sensitive adhesive composition comprising a polyurethane / urea resin (A) obtained from a polyol, an organic polyisocyanate and a chain extender. 2. The polyurethane / urea pressure-sensitive adhesive composition according to claim 1, wherein the polyurethane / urea resin (A) has a hydrazine residue. 3. The polyurethane / urea pressure-sensitive adhesive composition according to claim 1, wherein the polyurethane / urea resin (A) is an aqueous resin. 4. The polyurethane / urea pressure-sensitive adhesive composition according to claim 1, wherein a polyfunctional compound selected from the group consisting of polyisocyanate, polycarbodiimide and epoxy compound is blended with the polyurethane / urea resin (A). . 5. The coated polyurethane / urea pressure-sensitive adhesive composition according to claim 1, wherein the polyolefin film or sheet is used as an adherend.