JPH05306380A - Hotmelt tacky agent composition and tacky tape, label or sheet coated therewith - Google Patents

Abstract

PURPOSE:To obtain a composition containing a copolymer comprising a specific acrylic acid ester, a specific polymerizable polymer and a water soluble monomer in a specific ratio as a main component, excellent in melt coating property, tackiness, heat resistance and water soluble property and useful for tacky tapes, labels, etc. CONSTITUTION:The composition contains (A) 100 pts.wt. (meth)acrylic acid ester having 4-18C alkyl group, (B) 3-50 pts.wt. polymerizable polymer expressed by the formula (R<1> is H or CH3; R<2> is nonpolymerizable polymer-like segment having 2000-50000 weight-average molecular weight and >=50 deg.C Tg and (C) 25-400 pts.wt. water soluble monomer such as N-vinylpyrrolidone having a nitrogen atom in the molecule as main components. Furthermore, this composition is applied to the surface of a support to provide the tacky tape, label and sheet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot-melt pressure-sensitive adhesive composition and a pressure-sensitive adhesive tape, label or sheet coated with the hot-melt pressure-sensitive adhesive composition. Excellent adhesiveness, heat resistance, excellent weather resistance, and further by having water solubility or water dispersibility, the adhesive remaining on the surface of the adherend when separated from the surface of the adherend is treated with water. It relates to a hot-melt adhesive composition that can be wiped off.

[0002]

2. Description of the Related Art Conventionally, a hot-melt pressure-sensitive adhesive composition applied on one side or both sides of a support by hot-melting or a solvent-based or water-based pressure-sensitive adhesive composition applied and dried, for sealing, for packaging, It is used for various purposes such as marking, surface protection, masking, office work, home use, and adhesion.

As a hot-melt pressure-sensitive adhesive composition suitable for such use, for example, Japanese Patent Application Laid-Open No. 59-75975 discloses a pressure-sensitive adhesive composition obtained by copolymerizing acrylic acid ester and methacrylate-terminated polystyrene. .. However, such an adhesive composition is lacking in water solubility or water dispersibility, and the adhesive remaining on the adherend when peeled cannot be easily wiped off with water, and the appearance of the adherend is It lacks practicality when it is a product that requires aesthetics.

In order to solve such a drawback, for example, in JP-A-1-182354, a styrene-conjugated diene block copolymer or a hydrogenated product thereof and vinyl alcohol having an average degree of polymerization of 20 to 300 are disclosed. A hot melt pressure sensitive adhesive composition containing a copolymer has been proposed. However, such an adhesive composition has poor weather resistance and has a drawback that it is limited to indoor use or short-term use.

Further, when the adhesive is peeled from the surface of the adherend, the adhesive remaining on the adherend can be wiped off with water.
For example, in JP-A-51-5337 and JP-A-51-6236, a resin in which a copolymer of an acrylic ester and a monomer such as an ethylenically unsaturated carboxylic acid is neutralized with aminopropanol is used as a main agent. The solvent-based pressure-sensitive adhesive composition is disclosed. In this case, it is intended to make the copolymer water-soluble by neutralizing it, but since it neutralizes the carboxylic acid in the copolymer, the water resistance and moisture resistance required for the pressure-sensitive adhesive are required. There was a drawback that it was damaged.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and has good hot melt coating property on a support and excellent adhesion to an adherend. ,
It also provides a hot melt pressure-sensitive adhesive composition having excellent heat resistance and weather resistance. Further, the present invention, when peeled from the adherend, the hot-melt pressure-sensitive adhesive composition which can wipe off the adhesive remaining on the surface of the adherend with water and does not impair the aesthetics of the adherend and the same An adhesive tape, label or sheet coated with is provided.

[0007]

The hot-melt pressure-sensitive adhesive composition according to the present invention comprises (A) 100 parts by weight of a (meth) acrylic acid ester having an alkyl group with 4 to 18 carbon atoms (B) a general formula CH ₂ = CR ¹ —COOR ² (in the formula, R ¹ represents H or CH ₃ , and R ² represents a non-polymerizable polymeric segment having a weight average molecular weight of 2,000 to 50,000 and a Tg of 50 ° C. or higher). Polymerizable polymer 3-50
Parts by weight, (C) water-soluble monomer having a nitrogen atom in the molecule (c) 25 ~
400 parts by weight of a copolymer containing (A), (B) or (C) as a main component, or (c) of the above copolymer components in the molecule. Water-soluble monomer having hydroxyl group
(d) 60 to 400 parts by weight, or the general formula ^{_{CH 2 = CR 1 -COO- (R}} 3 -O) n -R 4 ··· (e) ( wherein, the R ¹ is H or CH _3, R ³ and R ⁴ are each a divalent or monovalent hydrocarbon group having 1 to 4 carbon atoms, and n is 1 to 40
Water-soluble monomer (e) 60 to 400 represented by
It is characterized in that it is replaced by parts by weight, whereby the above-mentioned problems can be achieved.

In the present invention, examples of the (meth) acrylic acid ester having an alkyl group having 4 to 18 carbon atoms include butyl (meth) acrylate, isobutyl (meth) acrylate, hexyl (meth) acrylate, and (meth) acrylate. ) 2-ethylhexyl acrylate, octyl (meth) acrylate,
Isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate and the like are used.

In the present invention, the general formula CH ₂ = CR ¹
-COOR ² (wherein R ¹ represents H or CH ₃ , R ² represents a non-polymerizable polymeric segment having a weight average molecular weight of 2,000 to 50,000 and Tg of 50 ° C. or higher) The polymerizable polymer is a so-called macromonomer, and has a polymerizable (meth) acryloyl group at one end and a non-polymerizable polymeric segment R ² at the other end. Tg is the glass transition temperature, which is said to be 50 ° C or higher,
The reason is that when Tg is less than 50 ° C., the heat resistance of the obtained pressure-sensitive adhesive composition becomes insufficient.

The weight average molecular weight of the non-polymerizable polymeric segment R ² is in the range of 2,000 to 50,000. The reason is that if the weight average molecular weight is less than 2,000, the heat resistance of the obtained pressure-sensitive adhesive composition becomes insufficient, and
If it is larger than 50,000, the reactivity of the polymerizable polymer is lowered.

As the non-polymerizable polymeric segment R ² , for example, polystyrene or its derivative, polymethyl methacrylate or its derivative is used. The amount of the polymerizable polymer used in the present invention is the same as the (meth)
It is 3 to 50 parts by weight, preferably 8 to 20 parts by weight, based on 100 parts by weight of the acrylic ester. The reason is that if the amount of the polymerizable polymer is less than 3 parts by weight, sufficient cohesive force cannot be obtained and the heat resistance of the pressure-sensitive adhesive is significantly reduced.
This is because if the amount is more than the amount by weight, it becomes difficult to secure a sufficient adhesive force.

In order to produce the polymerizable polymer in the present invention, the production method disclosed in, for example, US Pat. No. 3,786,116, US Pat. No. 3,842,059, JP-A-60-133007, etc. is applied. can do.

As the water-soluble monomer (c) having a nitrogen atom in its molecule in the present invention, for example, N-vinylpyrrolidone and its derivative, (meth) acrylic acid amide and its derivative and the like are used. As the water-soluble monomer having a hydroxyl group in the molecule (d), for example, (meth) glucosyl ethyl acrylate and the following general formula ^{_{CH 2 = CR 1 -COO- (Y}} -O) m -H ( wherein, R ¹ is H or CH ₃ , Y is a linear or branched alkylene group having 2 to 4 carbon atoms, and m is an integer of 1 to 50)
The (meth) acrylic acid ester represented by
Specific examples include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and tetraethylene glycol monoacrylate. Furthermore, the general formula CH
Examples of the water-soluble monomer (e) represented by ₂ = CR ¹ -COO- (R ³ -O) _n -R ⁴ include 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-butoxyethyl (meth) acrylate,
2-Methoxypropyl (meth) acrylic acid, etc., (meth) acrylic acid ester of triethylene glycol monomethyl ether, (meth) acrylic acid ester of triethylene glycol monoethyl ether, etc. may be mentioned.

By copolymerizing these water-soluble monomers with the (meth) acrylic acid ester and the polymerizable polymer, the water-solubility or water-dispersibility of the pressure-sensitive adhesive composition according to the present invention is improved.

In the case of the water-soluble monomer (c) having a nitrogen atom in the molecule, the amount of these water-soluble monomers used is 25 to 4 with respect to 100 parts by weight of the (meth) acrylic acid ester.
00 parts by weight, preferably 40-200 parts by weight, (d) or
In the case of the water-soluble monomer (e), the amount is 60 to 400 parts by weight, preferably 90 to 300 parts by weight, based on 100 parts by weight of the (meth) acrylic acid ester. The reason is that when the amount of the water-soluble monomer used is less than the above range, the water-solubility or water dispersibility of the obtained pressure-sensitive adhesive composition decreases, and when it exceeds the above range, the melt viscosity of the obtained pressure-sensitive adhesive composition is increased. Is extremely high and the melt coatability is deteriorated. The decrease in melt coatability can be improved by blending a viscosity-reducing agent, but it is necessary to blend in a large amount and the heat resistance tends to be degraded.

In the present invention, (meth) acrylic acid esters in which the alkyl group has 3 or less carbon atoms, if necessary;
Isobornyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate; saturated fatty acid vinyls such as vinyl acetate and vinyl versatate;
Styrene monomers such as styrene and α-methylstyrene; acrylonitrile; (meth) acrylic acid, itaconic acid, maleic acid, crotonic acid, maleic anhydride, olefin sulfonic acid and the like may be copolymerized.

In order to copolymerize the (meth) acrylic acid ester with the polymerizable polymer, the water-soluble monomer, and optionally other copolymerizable monomer, a radical polymerization method is adopted. Suitable, for example, produced by solution polymerization, bulk polymerization. In this case, as the polymerization initiator, for example, a peroxide type compound or an azo type compound is used, but it may be polymerized by irradiation with light or radiation. Further, in order to adjust the molecular weight, an appropriate chain transfer agent such as lauryl mercaptan may be used.

In the pressure-sensitive adhesive composition of the present invention, the (meth) acrylic acid ester is copolymerized with the polymerizable polymer, the water-soluble monomer and, if necessary, other copolymerizable monomer. Although the obtained copolymer alone has good melt coatability and tackiness, a softening agent can be added in order to improve or adjust the melt coatability and tackiness to a more suitable one. The formulation of the softener is
It is particularly advantageous when the water-soluble monomer accounts for a large proportion of the copolymer.

Examples of the softening agent include polyalkylene ether glycol compounds and their derivatives, glycerin, diglycerin, triglycerin, polyglycerin and their derivatives, hydrophilic compounds such as urea derivatives such as ethylene urea; dioctyl phthalate, Phthalates such as dicyclohexyl phthalate, phosphates such as triphenyl phosphate, fatty acids such as dioctyl adipate,
A benzoate-based compound such as glyceroyltribenzoate, a plasticizer such as polyester, or a hydrophobic compound such as aromatic or chlorinated paraffin is used. The blending amount of the softening agent is 300 parts by weight or less, and preferably 200 parts by weight or less with respect to 100 parts by weight of the copolymer.

Further, in order to impart a wide range of melt coatability, tackiness, and water solubility to the pressure-sensitive adhesive composition of the present invention, rosin and its derivatives, phenol derivatives such as terpene phenols, coumarone-indene resin, if necessary. Tackifying resins such as petroleum-based resins and xylene resins; sorbit, mannitol, xylit, dulcitt, pentaerythritol, trimethylolpropane, trimethylolethane and its derivatives, polyvinyl alcohol, modified polyvinyl alcohol, polyvinyl ether, vinyl acetate-N −
Water-soluble auxiliaries such as vinylpyrrolidone resin; vinyl acetate resin and its derivatives, ethylene-vinyl acetate resin and its derivatives or saponified products thereof, thermoplastic resins such as ethylene-acrylic acid resin, ethylene-ethyl acrylate resin; styrene A thermoplastic rubber-like resin such as a butadiene block copolymer resin and its hydrogenated resin; a wax such as paraffin wax, microcrystalline wax, polyethylene oxide wax, etc. may be blended, and a hindered phenol-based resin -Based, amine-based antioxidants; fillers such as calcium carbonate, talc, and clay; titanium oxide, zinc oxide, phthalocyanine-based, anthraquinone-based dyes and pigments, etc. may be added.

The pressure-sensitive adhesive composition according to the present invention is applied to a support to give a pressure-sensitive adhesive tape, label or sheet. As the coating method, a roll, a die, a hot melt applicator such as a nozzle may be directly applied to a support such as a tape, a label, or a sheet, or may be applied to the support by transfer. It may be applied on one side or both sides. The coating may be applied to the entire surface of the support or may be applied partially. The coating thickness varies depending on the use, but is preferably 10 to 200 μm. Examples of the material for the support include synthetic resin films such as polyethylene terephthalate, cellophane film, art paper, paper such as high-quality paper, cloth or non-woven fabric made of natural fibers or synthetic fibers,
Foam such as polyurethane and polyethylene is used.

[0022]

The adhesive composition according to the present invention comprises 3 to 50 parts by weight of the polymerizable polymer and 100 parts by weight of the (meth) acrylic acid ester, and the water-soluble monomer (c) having a nitrogen atom in the molecule. ) 25 to 400 parts by weight, or 60 to 400 parts by weight of a water-soluble monomer (d) having a hydroxyl group in the molecule,
Alternatively, the water-soluble monomer represented by the general formula (e) (e) 60 ~
Since it contains a copolymer obtained by copolymerizing 400 parts by weight, it exhibits an appropriate viscosity by heat melting and has excellent melt coatability.

The (meth) acrylic acid ester is excellent in adhesiveness and weather resistance, and since the polymerizable polymer is a copolymerization component, it has excellent cohesive force and heat resistance. .. Furthermore, since the water-soluble monomer is used as a copolymerization component, the water solubility or water dispersibility of the pressure-sensitive adhesive composition is improved.

Since the pressure-sensitive adhesive tape, label or sheet of the present invention has the above-mentioned pressure-sensitive adhesive composition applied to form a pressure-sensitive adhesive layer, it has excellent adhesiveness to an adherend and When peeled off, the adhesive remaining on the surface of the adherend can be wiped off with water, and the aesthetic appearance of the adherend is not impaired.

[0025]

EXAMPLES In order to explain the present invention in more detail, examples will be described below. In the examples, "parts" means "parts by weight". (Example 1) 2-ethylhexyl acrylate 100 was placed in a separable flask equipped with a reflux condenser, a thermometer, and a stirrer.
Parts, polystyrene having one end methacrylated (manufactured by Sartomer Co., trade name: Macromer 13K-PSMA, weight average molecular weight 13,000, Tg 100 ° C.) 10 parts, N-vinylpyrrolidone 60 parts, and lauryl mercaptan 0.1 part, After 85 parts of ethyl acetate and 85 parts of ethyl alcohol were added and uniformly mixed and dissolved, the temperature was raised, and 0.01 parts of azobisisobutyronitrile was dropped every hour while refluxing ethyl acetate and ethyl alcohol. Radical polymerization for 6 hours
A solution containing a copolymer having a weight average molecular weight of 10,000 was obtained.

In the copolymer solution thus obtained, 40 parts of dioctyl phthalate, 10 parts of sorbit, 30 parts of pentaerythritol ester of disproportionated rosin (softening point: 115 ° C.), anti-aging agent (Ciba Geigy, trade name: IRGA) Knox
1010) 1 part was uniformly blended, and the solvent was volatilized by heating to obtain a pressure-sensitive adhesive composition.

This composition was melted at 160 ° C., and a die coater (Acumeter Laboratory Co., USA, trade name: Accumeter LH-1 type) was used to form an adhesive on a polyethylene terephthalate film having a thickness of 50 μm. A hot melt adhesive sheet was obtained by applying the composition so that the layer thickness was 25 μm.

Performance test of this hot melt adhesive sheet
The following measurement method was used. Melt coatability : Adhesion during production of hot melt adhesive sheet
Dispersibility of Agent Composition and Polyethylene Terephthalate Film
Visually check the state of adhesion on the rum.Adhesive force : Stainless steel plate according to JIS Z 0237
Adhesiveness to is measured by peeling at 180 degrees.Holding power : According to JIS Z 0237, the area of 25mm × 25mm
Put the melted adhesive sheet on the stainless steel plate
Then, apply a load (weight) of 1 kg in an oven at 40 ° C
Measures the time until it falls.Water soluble : Apply water to the adhesive layer of the hot melt adhesive sheet.
Wipe with gauze soaked, the number of times the adhesive layer is completely gone
Measure.

The column of copolymer composition of Example 1 in Table 1 shows the parts by weight of each component used in obtaining the copolymer according to the present invention. In addition, in the column of blending components of Example 1 in Table 1, the blending ratio of each component of the pressure-sensitive adhesive composition containing this copolymer is shown in parts by weight. Further, the measurement results of the performance test are shown in the column of performance evaluation of Example 1 in Table 1.

(Examples 2 to 7) By applying the same method as described in Example 1 and using the components shown in the column of copolymerization composition of Examples 2 to 7 in Table 1, copolymers A solution was obtained. Then, a method similar to that described in Example 1 was applied to obtain a pressure-sensitive adhesive composition containing the components shown in the compounding ingredients column of Examples 2 to 7 in Table 1. In addition, polyethylene glycol having an average molecular weight of 600 was blended, and styrene-based petroleum resin having a softening point of 100 ° C. was blended. Using the pressure-sensitive adhesive composition thus obtained, the same method as in Example 1 was applied to obtain a hot-melt pressure-sensitive adhesive sheet. The measurement results of the performance test of this hot melt adhesive sheet are shown in Examples 2 to 7 in Table 1.
It is shown in the column of performance evaluation.

(Comparative Examples 1 to 5) By applying the same method as described in Example 1 and using each component shown in the column of copolymer composition of Comparative Examples 1 to 5 in Table 1, copolymers A solution was obtained. Then, the same method as described in Example 1 was applied to obtain a pressure-sensitive adhesive composition including each component shown in the column of compounding ingredients of Comparative Examples 1 to 5 in Table 1. Using the pressure-sensitive adhesive composition thus obtained,
A hot melt adhesive sheet was obtained by applying the same method as in Example 1. The measurement results of the performance test of this hot melt adhesive sheet are shown in the column of performance evaluation of Comparative Examples 1 to 5 in Table 1.

[0032]

[Table 1]

(Examples 8 to 16) The same method as described in Example 1 was applied except that the ratio of the polymerization solvent was changed, and the results are shown in the column of copolymer composition of Examples 8 to 16 in Table 2. A copolymer solution was obtained using each component. Then, a method similar to that described in Example 1 was applied to obtain a pressure-sensitive adhesive composition containing each component shown in the column of blended components of Examples 8 to 16 in Table 2. As the polyethylene glycol, one having an average molecular weight of 600 was blended, and as the rosin ester resin, pentaerythritol ester of disproportionated rosin having a softening point of 115 ° C. was blended. Using the pressure-sensitive adhesive composition thus obtained, Example 1
A hot melt pressure-sensitive adhesive sheet was obtained by applying the same method as described above. The measurement results of the performance test of this hot melt adhesive sheet are shown in the column of performance evaluation of Examples 8 to 16 in Table 2.

(Comparative Examples 6 to 10) Similar to Examples 8 to 16,
Each component shown in the column of the copolymer composition of Comparative Examples 6 to 10 in Table 2 was used to obtain a copolymer solution, and then an adhesive consisting of each component shown in the column of the blended components of Comparative Examples 6 to 10 in Table 2. An agent composition was obtained. Using the pressure-sensitive adhesive composition thus obtained, Example 1
A hot melt pressure-sensitive adhesive sheet was obtained by applying the same method as described above. The measurement results of the performance test of this hot melt adhesive sheet are shown in the column of performance evaluation of Comparative Examples 6 to 10 in Table 2.

[0035]

[Table 2]

(Examples 17 to 26) A method similar to that described in Example 1 was applied except that the ratio of the polymerization solvent was changed, and the results are shown in the column of copolymer composition of Examples 17 to 26 in Table 3. A copolymer solution was obtained using each component. Then, the same method as described in Example 1 was applied to obtain a pressure-sensitive adhesive composition composed of the components shown in the compounding ingredients column of Examples 17 to 26 in Table 3. As the polyethylene glycol, one having an average molecular weight of 2000 was blended, and as the rosin ester resin, pentaerythritol ester of disproportionated rosin having a softening point of 115 ° C. was blended. Using the pressure-sensitive adhesive composition thus obtained, Example 1
A hot melt pressure-sensitive adhesive sheet was obtained by applying the same method as described above. The measurement results of the performance test of this hot melt adhesive sheet are shown in the column of performance evaluation of Examples 17 to 26 in Table 3.

The moisture resistance was evaluated as follows. Moisture resistance : Adhesive sheet in an atmosphere of 40 ° C x 80% RH 7
After curing for a day, according to JIS Z 0237, apply it to a stainless steel plate with an area of 25 mm × 25 mm, apply a load (weight) of 1 kg in a test tank of 40 ° C × 80% RH, and measure the drop time of the weight.

Comparative Examples 11 to 15 Similar to Examples 17 to 26,
Each component shown in the column of copolymerization composition of Comparative Examples 11 to 15 in Table 3 was used to obtain a copolymer solution, and then an adhesive consisting of each component shown in the column of compounding components of Comparative Examples 11 to 15 in Table 3. An agent composition was obtained. Using the pressure-sensitive adhesive composition thus obtained, Example 1
A hot melt pressure-sensitive adhesive sheet was obtained by applying the same method as described above. The measurement results of the performance test of this hot melt adhesive sheet are shown in the column of performance evaluation of Comparative Examples 11 to 15 in Table 3.

[0039]

[Table 3]

As shown in these results, the pressure-sensitive adhesive composition according to the present invention has good melt coatability, excellent adhesion and holding power, has water solubility, and is easy to wipe off the pressure-sensitive adhesive layer. It was

[0041]

The hot-melt pressure-sensitive adhesive composition according to the present invention has a good hot-melt coating property on a support such as a tape, a label or a sheet. Therefore, a hot-melt applicator such as a roll, a die or a nozzle is used. It can be applied easily.

The pressure-sensitive adhesive tape, label or sheet according to the present invention has excellent adhesiveness to an adherend, and also has excellent heat resistance and weather resistance. Further, by having water solubility or water dispersibility, the adhesive remaining on the surface of the adherend when peeled from the surface of the adherend can be wiped off with water, which may impair the aesthetic appearance of the surface of the adherend. There will be nothing.

Claims (4)

[Claims] 1. (A) 100 parts by weight of a (meth) acrylic ester having an alkyl group with 4 to 18 carbon atoms, (B) a general formula CH ₂ ═CR ¹ —COOR ² (wherein R ¹ is H or CH ₃ and R ² are non-polymerizable polymeric segments having a weight average molecular weight of 2,000 to 50,000 and a Tg of 50 ° C. or higher)
Parts by weight, (C) water-soluble monomer having a nitrogen atom in the molecule
(c) A hot melt pressure-sensitive adhesive composition containing 25 to 400 parts by weight of a copolymer comprising (A), (B) and (C) as a main component. 2. A hot-melt pressure-sensitive adhesive composition, wherein the water-soluble monomer (c) of claim 1 is replaced with 60 to 400 parts by weight of a water-soluble monomer (d) having a hydroxyl group in the molecule. 3. The water-soluble monomer (c) according to claim 1 having the general formula CH ₂ ═CR ¹ —COO— (R ³ —O) _n —R ⁴ ... (e) (wherein R ¹ is H or CH ₃ , R ³ and R ⁴ are each a divalent or monovalent hydrocarbon group having 1 to 4 carbon atoms, and n is 1 to 40.
Water-soluble monomer (e) 60 to 400 represented by
A hot-melt pressure-sensitive adhesive composition, characterized in that it is replaced by parts by weight. 4. A pressure-sensitive adhesive tape, label or sheet obtained by applying the pressure-sensitive adhesive composition according to claim 1 on one side or both sides of a support.