JPH0551566A - Acrylic pressure-sensitive adhesive composition and pressure-sensitive adhesive tape, label or sheet - Google Patents

Abstract

PURPOSE:To obtain an adhesive composition excellent in initial tack and long- term tack to a plasticized flexible vinyl chloride resin and in the productivity of a pressure-sensitive adhesive tape by mixing a specified acrylic resin with an aziridine compound and a specified melamine or benzoguanamine compound. CONSTITUTION:An acrylic pressure-sensitive adhesive composition comprising 100 pts.wt. acrylic resin, 0.01-1 pt.wt. aziridine compound having at least two aziridinyl groups or substituted aziridinyl groups in the molecule and 0.5-5 pts.wt. melamine etherified with an alcohol or a benzoguanamine compound etherified with an alcohol, wherein the acrylic resin mainly consists of a copolymer of an alkyl (meth)acrylate with a vinyl compound having a functional group reactive with the aziridine compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an acrylic pressure-sensitive adhesive composition and pressure-sensitive adhesive composition which are excellent in initial sticking property and sticking property over time to a soft vinyl chloride resin containing a plasticizer and are excellent in productivity. It relates to adhesive tapes, labels and the like.

[0002]

2. Description of the Related Art Conventionally, a soft vinyl chloride resin containing a plasticizer or a soft vinyl chloride containing a plasticizer has been used as a material for a pressure-sensitive adhesive tape using an acrylic pressure-sensitive adhesive composition. When a pressure-sensitive adhesive tape using an acrylic adhesive composition is attached to a resin-based product as an adherend, the plasticizer migrates from the soft vinyl chloride resin to the acrylic pressure-sensitive adhesive layer over time. However, this causes a problem that the adhesive performance of the acrylic pressure-sensitive adhesive is significantly reduced.

However, conventionally, as a measure for preventing the deterioration of the adhesive performance due to the passage of time of the plasticizer of the acrylic pressure sensitive adhesive, for example, as described in JP-A-53-94519, the acrylic adhesive is used. The agent contains a resol type phenolic resin, or the adhesive contains a tackifying resin in addition to the resole type phenolic resin as described in JP-A-58-109572.
As described in Japanese Patent No. 384, the acrylic pressure-sensitive adhesive may contain a crosslinkable monomer and a metal complex, or JP-A-63-2
As described in JP-A-30783, an acrylic pressure-sensitive adhesive may contain nitrification cotton, or an acrylic pressure-sensitive adhesive may be mixed with an alcohol-etherified melamine compound or an alcohol-etherified benzoguanamine compound. A method of advancing a crosslinking reaction at a temperature of 80 ° C. or higher during the production of pressure-sensitive adhesive tapes has been proposed.

[0004]

However, in any of the conventional cases as described above, the cross-linking reaction for giving tackiness takes a long time, so that the productivity is low when producing an adhesive tape or the like. There was a problem.

The present application is excellent in initial sticking property and sticking property with time to a soft vinyl chloride resin containing a plasticizer,
In addition, it is an object of the present invention to provide an acrylic pressure-sensitive adhesive composition and a pressure-sensitive adhesive tape, a label or a sheet which are excellent in productivity such as a pressure-sensitive adhesive tape.

[0006]

The invention according to claim 1 of the present application provides 100 parts by weight of an acrylic resin (a) and an aziridine compound (b) having two or more aziridinyl groups or substituted aziridinyl groups in one molecule. An acrylic pressure-sensitive adhesive composition containing 0.01 to 1 part by weight and 0.5 to 5 parts by weight of alcohol-etherified melamine or alcohol-etherified benzoguanamine compound (c). An acrylic pressure-sensitive adhesive composition in which the acrylic resin (a) is mainly a copolymer of (meth) acrylic acid alkyl ester and a vinyl compound having a functional group having a chemical bond with the aziridine compound (b). It is a thing.

The invention according to claim 2 of the present invention is a pressure-sensitive adhesive tape, label or sheet using the acrylic pressure-sensitive adhesive composition according to claim 1. As the acrylic resin (a) used in the present application, a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 12 carbon atoms and a vinyl compound having a functional group having a chemical bond with an aziridine compound are copolymerized. Obtained.

Examples of the (meth) acrylic acid alkyl ester include ethyl (meth) acrylate, n-butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate and lauryl. (Meth) acrylate or the like can be used.

As the vinyl compound having a functional group having a chemical bond with the aziridine compound, a carboxyl group-containing monomer such as acrylic acid, methacrylic acid, itaconic acid, fumaric acid or maleic acid is used as an essential component.
The content ratio thereof is preferably 0.5 to 10% by weight based on the whole monomers constituting the acrylic resin.

If desired, monomers such as acrylamide, vinylpyrrolidone and 2-hydroxy (meth) acrylate may be contained. The aziridine compound (b) used in the present application is a compound having two or more aziridinyl groups or substituted aziridinyl groups represented by the following general formula in one molecule.

[0011]

[Chemical 1]

Specific examples of the aziridine compound (b) include N, N'-hexamethylene-1,6-bis (1-aziridinecarboxamide), trimethylolpropane-tri-β-aziridinylpropio. And bisisophthaloyl-1- (2-methylaziridine) and the like, and two or more of them may be used in combination.

The content ratio of the aziridine compound is 0.01 to 1 part by weight based on 100 parts by weight of the acrylic resin. When the amount is less than 0.01 parts by weight, the gel fraction does not increase, the cohesive force of the adhesive is small, and when the adhesive is attached to the soft vinyl chloride resin, the adhesive fixability decreases with the migration of the plasticizer. On the contrary, if it is more than 1 part by weight,
The gel fraction of the pressure-sensitive adhesive layer becomes too high and the adhesive strength is reduced.

Here, the gel fraction refers to the crosslinking of the pressure sensitive adhesive.
An index showing the degree of pressure sensitive adhesive W ₀g is a large excess of tet
Soak in Lahydrofuran for 24 hours at 20 ℃
Solubilized in tetrahydrofuran,
The insoluble portion recovered by filtration with a wire mesh at 3
Dry for hours, its weight W₁To measure. Gel fraction is W ₁
/ W₀× 100% is displayed.

The alcohol etherified melamine compound (c) used in the present application is a compound represented by the following general formula.

[0016]

[Chemical 2]

Specific examples of the melamine compound aerylated with alcohol include methylated melamine, butylated melamine and the like. The benzoguanamine compound (c) etherified with alcohol used in the present application is a compound represented by the following general formula.

[0018]

[Chemical 3]

Specific examples of the benzoguanamine compound etherified with alcohol include butylated benzoguanamine. The content of the melamine compound etherified with alcohol or the benzoguanamine compound etherified with alcohol is the same as that of acrylic resin 1
It is used in the range of 0.5 to 5 parts by weight with respect to 00 parts by weight, and particularly preferably in the range of 1 to 3 parts by weight. If it is less than 0.5 parts by weight, the above effect cannot be expected. On the contrary, if it exceeds 5 parts by weight, the resin becomes too hard and the adhesive strength is rather lowered.

The copolymer used in the present invention preferably has a weight average molecular weight of 200,000 to 1,000,000. When it is less than 200,000, the cohesive force of the obtained pressure-sensitive adhesive tends to be weak, and conversely 100.
If it exceeds 10,000, the viscosity becomes too high,
This is because the productivity of the pressure sensitive adhesive tape, label or sheet tends to decrease.

The copolymer used in the present invention has a glass transition temperature (1 by viscoelasticity spectrometer).
The tan δ peak value in the measured spectrum at 0 Hz) is preferably in the range of 0 to -25 ° C. If it exceeds 0 ° C, the initial adhesive force tends to be small, and conversely, if it is less than -25 ° C, the aging cohesive force when the plasticizer from the soft vinyl chloride resin migrates decreases. This is because there is a tendency. The control of the glass transition temperature of the copolymer is determined by the type and amount of the (meth) acrylic acid alkyl ester, the vinyl compound having a functional group, and other vinyl compounds added as necessary.

In the present invention, known additives such as tackifying resins such as petroleum resin, terpene resin, rosin resin, coumarone indene resin and phenol resin, various stabilizers and fillers may be blended.

[0023]

Since the acrylic pressure-sensitive adhesive composition of the present invention contains a specific amount of the aziridine compound, it is possible to promote the crosslinking reaction of the acrylic resin in a short time to impart tackiness. When the pressure-sensitive adhesive tape or the like of the present invention using a product is produced, the productivity is excellent.

Further, since it contains a specific amount of an alcohol-etherified melamine compound or an alcohol-etherified benzoguanamine compound, a pressure-sensitive adhesive tape having an acrylic pressure-sensitive adhesive layer formed thereon is a plasticizer. When attached to a soft vinyl chloride resin containing
Self-crosslinking of the melamine compound etherified with alcohol or the etherified benzoguanamine compound with alcohol over time and the crosslinking with the acrylic resin proceed to prevent the softening of the pressure-sensitive adhesive layer accompanying the plasticizer migration,
It is presumed that it is excellent in sticking property with time to a soft vinyl chloride resin.

Since the pressure-sensitive adhesive tape, label or sheet of the present invention uses the above acrylic pressure-sensitive adhesive composition, it is excellent in initial sticking property and sticking property with time on soft vinyl chloride resin. Is.

[0026]

EXAMPLES Examples of the present invention will be described below. Example 1 (1) Preparation of acrylic resin liquid 75 parts by weight of n-butyl acrylate, 20 parts by weight of ethyl acrylate, 5 parts by weight of acrylic acid, 0.03 part by weight of n-dodecyl mercaptan, 60 parts by weight of ethyl acetate were placed in a cooling pipe. Place in a separable flask equipped with and heat to 1
Blow nitrogen gas for 0 minutes, add 0.024 parts by weight of benzoyl peroxide in 3 portions under reflux of ethyl acetate, and add dropwise.
After reacting for a time, 0.036 parts by weight was further added dropwise and aged for 2 hours. The acrylic resin liquid thus obtained had a solid content of 59.5% and a weight average molecular weight of 60.
10,000, and the glass transition temperature was -15 ° C. In addition, n-dodecyl mercaptan was blended in order to adjust the molecular weight.

(2) Production of Pressure-Sensitive Adhesive Tape The above acrylic resin liquid was mixed with N, as an aziridine compound.
N'-hexamethylene-1,6-bis (1-aziridinecarboxamide) (manufactured by Mutual Pharmaceutical Co., Ltd .: trade name "HD
U ") 0.05 parts by weight and 1 part by weight of butylated melamine as a melamine compound are mixed, and the resulting acrylic pressure-sensitive adhesive liquid is applied to a polyester film having a thickness of 38 μm and pressure-sensitive adhesion after drying. The pressure-sensitive adhesive tape was manufactured by applying the agent layer to a thickness of 25 μm and then drying at 80 ° C. for 3 minutes.

(3) Physical Property Test A test piece was prepared from this pressure-sensitive adhesive tape, and the following physical property test was conducted. The results are shown in Table 1.

SP Adhesiveness According to JIS Z0237, a test piece was attached to SUS-304 with a width of 15 mm, and the 180 ° peel strength after standing at 23 ° C. for 20 minutes was measured. Pulling speed is 300m
It was set to m / min.

Holding power According to JIS Z0237, a test piece is attached to SUS-304 with a size of 20 × 20 mm, and 40 ° C. and 80 ° C.
Put in a constant temperature bath of 1 and apply a load of 1 kg. The tape deviation (or drop time) after 1 hour was measured.

Peeling force with time against soft vinyl chloride resin To 100 parts by weight of vinyl chloride resin having a degree of polymerization of 1100, 50 parts by weight of dioctyl phthalate as a plasticizer, 15 parts by weight of calcium bicarbonate as a filler, and various other stabilizers are mixed. The test piece was attached to a plate made of soft vinyl chloride resin having a thickness of 5 mm with a width of 15 mm, allowed to stand at 80 ° C. for 2 weeks, then returned to room temperature, and the 180 ° C. peel strength was measured.

Retention force with time against soft vinyl chloride resin A test piece was attached to a plate made of the same soft vinyl chloride resin as above, and after two weeks at 80 ° C, the shear retention force was measured at 40 ° C. Adhesive area is 20 × 20mm, load is 50
It was carried out under the condition of 0 g.

Example 2 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that butylated melamine as a melamine compound was used in an amount of 3 parts by weight, and its physical properties were measured. The results are shown in Table 1.

Example 3 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that HDU as an aziridine compound was 0.02 part by weight and methylated melamine as a melamine compound was 3 parts by weight. The physical properties were measured. The results are shown in Table 1.

Example 4 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that HDU as an aziridine compound was changed to 0.08 part by weight, and its physical properties were measured. The results are shown in Table 1.

Example 5 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that 1 part by weight of butylated benzoguanamine as a benzoguanamine compound was mixed in place of the melamine compound, and its physical properties were measured. The results are shown in Table 1.

Example 6 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that 3 parts by weight of butylated benzoguanamine as a benzoguanamine compound was mixed in place of the melamine compound, and its physical properties were measured. The results are shown in Table 1.

Example 7 1 part by weight of methylated melamine as a melamine compound was added,
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that 1 part by weight of methylated melamine as the melamine compound and 1 part by weight of butylated benzoguanamine as the benzoguanamine compound were used, and the physical properties were measured. The results are shown in Table 1.

Comparative Example 1 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that HDU as an aziridine compound was 0 and butylated melamine as a melamine compound was 3 parts by weight, and its physical properties were measured. did. The results are shown in Table 2.

Comparative Example 2 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that HDU as an aziridine compound was 2 parts by weight and methylated melamine as a melamine compound was 3 parts by weight. It was measured. The results are shown in Table 2.

Comparative Example 3 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that the butylated melamine as the melamine compound was set to 0, and the physical properties were measured. The results are shown in Table 2.

Comparative Example 4 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that 10 parts by weight of butylated melamine as a melamine compound was used, and its physical properties were measured. The results are shown in Table 2.

Comparative Example 5 The pressure-sensitive adhesive tape of Comparative Example 1 was dried and aged at 80 ° C. for 3 days, and the physical properties were measured. The results are shown in Table 2.

Comparative Example 6 Except that HDU as an aziridine compound was set to 0 and 3 parts by weight of butylated benzoguanamine as a benzoguanamine compound was mixed instead of the melamine compound.
A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 and its physical properties were measured. The results are shown in Table 2.

Comparative Example 7 Pressure-sensitive adhesion was performed in the same manner as in Example 1 except that HDU as an aziridine compound was 2 parts by weight and 3 parts by weight of butylated benzoguanamine as a benzoguanamine compound was mixed instead of the melamine compound. A tape was manufactured and the physical properties were measured. The results are shown in Table 2.

Comparative Example 8 A pressure-sensitive adhesive tape was produced in the same manner as in Example 1 except that 10 parts by weight of butylated benzoguanamine as a benzoguanamine compound was mixed in place of the melamine compound, and its physical properties were measured. The results are shown in Table 2.

Comparative Example 9 The pressure-sensitive adhesive tape of Comparative Example 6 was dried and aged at 80 ° C. for 3 days, and the physical properties were measured. The results are shown in Table 2.

[0048]

[Table 1]

[0049]

[Table 2]

As is clear from Tables 1 and 2, in the case of the examples of the present invention, the SP adhesive strength and the holding power showing the initial sticking property are both high, and the plasticizer against the soft vinyl chloride resin is used. It has excellent peeling power and holding power against soft vinyl chloride resin, which shows adhesiveness with time when it is transferred. On the other hand, in the case of Comparative Example, as in Comparative Example 5 or Comparative Example 9, except that the tape was aged for 3 days at 80 ° C., which requires a complicated manufacturing process, initial sticking property or soft vinyl chloride resin was used. At least one of the time-dependent stickiness is inferior.

[0051]

[Effect] Since the acrylic pressure-sensitive adhesive composition of the present invention has the above-mentioned constitution, it is excellent in initial sticking property and sticking property over time to a soft vinyl chloride resin containing a plasticizer, and Excellent productivity as affixed labels, tapes, sheets, foams, etc.

Since the pressure-sensitive adhesive tape, label or sheet of the present invention has the above-mentioned constitution, it is excellent in initial sticking property and sticking property with time to a soft vinyl chloride resin.

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location C09J 7/02 JKK 6770-4J

Claims (2)

[Claims] 1. Acrylic resin (a) 100 parts by weight and 1
0.01 to 1 part by weight of an aziridine compound (b) having two or more aziridinyl groups or substituted aziridinyl groups in the molecule, melamine etherified with alcohol or benzoguanamine compound (c) 0.5 etherified with alcohol. An acrylic pressure-sensitive adhesive composition containing 5 to 5 parts by weight, wherein the acrylic resin (a) is a functional group having a chemical bond mainly with a (meth) acrylic acid alkyl ester and an aziridine compound (b). An acrylic pressure-sensitive adhesive composition comprising a copolymer with a vinyl compound having a group. 2. A pressure-sensitive adhesive tape, label or sheet comprising the acrylic pressure-sensitive adhesive composition according to claim 1.