JPH07292333A - Adhesive composition and paper tube using the same - Google Patents

Abstract

PURPOSE:To provide an adhesive composition which mainly comprises a vinyl acetate resin emulsion and has excellent water resistance and high initial adhesion, and a paper tube produced using this adhesive composition. CONSTITUTION:This adhesive composition is characterized by mainly comprising a vinyl acetate resin emulsion prepared by emulsion polymerization of 100 pts.wt. of vinyl acetate monomer and 110 pts.wt. of N-methylolacrylamide, and a paper (cardboard) tube is produced using the adhesive composition.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to an adhesive composition containing a vinyl acetate resin emulsion as a main component, which is used for paper tubes, paper packaging, woodworking, general purposes, etc., and the adhesive composition. The present invention relates to a paper tube made by using the paper tube.

[0002]

2. Description of the Related Art A paper tube is manufactured by winding a strip of paper on a metal core in a plurality of layers and adhering the polymerized portion of the strip of paper with an adhesive. The adhesive used in this case is , Based on one or more of aqueous solutions of starch, polyvinyl alcohol and the like, and vinyl acetate resin emulsions using polyvinyl alcohol as a protective colloid.

On the other hand, an adhesive for paper tubes is required to have an initial adhesive strength to withstand the restoring force of a strip-shaped paper piece wound around a metal core, and water resistance, adhesive strength, and pressure resistance after being made into a paper tube. There is.

However, since an adhesive composition containing a vinyl acetate resin emulsion as a main component generally has poor water resistance, in order to improve the water resistance of this adhesive composition, in order to improve the water resistance of polyvinyl alcohol, ammonium persulfate or the like is added in the presence of polyvinyl alcohol. Vinyl acetate resin emulsion obtained by emulsion polymerization of persulfate and divinyl compound, polyallyl ester, polyallyl ether, poly (meth) acrylate and other compounds having two or more ethylenically unsaturated hydrocarbon groups. An adhesive composition containing as a main component has been proposed (Japanese Patent Publication No.
No. 5-24476).

However, the adhesive composition proposed above is
Although the water resistance is improved, the initial adhesive strength is insufficient,
It is not practical as an adhesive for paper tubes.

In order to improve the initial adhesive strength of an adhesive composition containing a vinyl acetate resin emulsion as a main component,
A method for producing a vinyl acetate resin emulsion has been proposed in which polyvinyl alcohol having an average degree of polymerization of about 200 to 800 and having a low degree of polymerization is used as a protective colloid, and a surfactant and a plasticizer are used in combination to improve initial adhesive strength. (Japanese Patent Laid-Open No. 57-100107).

However, as described above, an adhesive composition containing polyvinyl alcohol having a low polymerization degree as a protective colloid and a vinyl acetate resin emulsion obtained by using a surfactant and a plasticizer together as a main component is Since the cohesive force of the dry film is weakened, there is a problem that the adhesive strength, water resistance, etc. of the produced paper tube are remarkably inferior, and it is not practical as an adhesive for paper tubes.

[0008]

In view of the above points, the present invention provides an adhesive composition containing a vinyl acetate resin emulsion as a main component, which has excellent water resistance and initial adhesive strength, and the adhesive composition. An object of the present invention is to provide a paper tube manufactured by using.

[0009]

The adhesive composition according to the invention of claim 1 (hereinafter referred to as "first invention") comprises 100 parts by weight of vinyl acetate monomer and 0.1 to 10 parts by weight of N-methylol acrylamide. And a vinyl acetate-based resin emulsion obtained by emulsion polymerization.

In a paper tube according to the invention of claim 2 (hereinafter referred to as "second invention"), a strip-shaped paper piece is wound in a tubular shape, and the overlapped portion of the tubular paper piece wound in the tubular shape is 1 is bonded by the adhesive composition according to the invention.

The vinyl acetate resin emulsion, which is the main component of the adhesive composition according to the first aspect of the present invention, has 0.1 to 10 parts by weight of N-methylolacrylamide copolymerized with 100 parts by weight of vinyl acetate monomer. Water resistance is greatly improved and excellent initial adhesive strength is retained.

In the above vinyl acetate resin emulsion, the amount of N-methylol acrylamide must be 0.1 to 10 parts by weight based on 100 parts by weight of vinyl acetate monomer.

If the amount of N-methylolacrylamide is less than 0.1 parts by weight per 100 parts by weight of vinyl acetate monomer, the water resistance of the resulting adhesive composition will not be improved,
On the other hand, if it exceeds 10 parts by weight, the viscosity rapidly increases during emulsion polymerization or a large amount of aggregates are generated, and a preferable vinyl acetate resin emulsion cannot be obtained.

In the vinyl acetate resin emulsion according to the first aspect of the present invention, a vinyl acetate monomer and an ethylenically unsaturated monomer other than N-methylolacrylamide are copolymerized, if necessary, within a range that does not impair the object of the present invention. May be.

The type of the ethylenically unsaturated monomer is not particularly limited, but it is (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl acrylate, 2-ethylhexyl acrylate, ethylene. Glycol mono (meth) acrylate, ethylene glycol di (meth) acrylate,
Propylene glycol (meth) acrylate, glycidyl (meth) acrylate, etc. are mentioned, and these 1 type (s) or 2 or more types are used suitably. The term "(meth) acrylic" used herein means "acrylic" or "methacrylic".

The amount of the ethylenically unsaturated monomer is not particularly limited, but the amount of the ethylenically unsaturated monomer is 0.
It is preferably in the range of 1 to 10 parts by weight.

The vinyl acetate resin emulsion in the first invention is not based on a special polymerization method, but an aqueous solution of a water-soluble polymer such as polyvinyl alcohol,
Alternatively, using a mixed aqueous solution of a water-soluble polymer and a surfactant as a protective colloid, hydrogen peroxide, ammonium persulfate, potassium persulfate, persulfate such as sodium persulfate,
It can be obtained by emulsion polymerization according to a conventional method using one or more reducing agents such as tartaric acid, formic acid and oxalic acid as a polymerization catalyst.

Polyvinyl alcohol is most commonly used as the protective colloid, and the average degree of polymerization of the polyvinyl alcohol is not particularly limited, but it is preferably 1000 to 2500, and particularly 1500. More preferably, it is 2,000. When the average degree of polymerization of polyvinyl alcohol is less than 1000, the dry film strength of the vinyl acetate-based resin emulsion obtained becomes weak. On the contrary, when it exceeds 2500, the viscosity of the vinyl acetate-based resin emulsion obtained becomes too high and the initial Adhesive strength and coating workability are reduced.

The saponification degree of the polyvinyl alcohol is not particularly limited, but is preferably 80 to 99 mol%, and more preferably 94 to 98 mol%. The degree of saponification of polyvinyl alcohol is 80
If it is less than mol%, the water resistance of the obtained vinyl acetate resin emulsion will be lowered, and conversely, if it exceeds 99 mol%,
The stability during emulsion polymerization becomes poor.

The amount of the polyvinyl alcohol is not particularly limited, but vinyl acetate monomer, N
-Polyvinyl alcohol is preferably 0.1 to 30 parts by weight, and more preferably 1 to 20 parts by weight, based on 100 parts by weight of the total amount of methylol acrylamide and the ethylenically unsaturated monomer. When the amount of polyvinyl alcohol used is less than 0.1 parts by weight based on 100 parts by weight of the total amount of monomers, initial polymerization is difficult to occur, and when it exceeds 30 parts by weight, the viscosity of the resulting vinyl acetate resin emulsion is It becomes too high, and the initial adhesive strength and coating workability deteriorate.

The amount of the polymerization catalyst used is not particularly limited, but is preferably 0.01 to 2 parts by weight with respect to 100 parts by weight of the total amount of the monomers.

The adhesive composition according to the first invention contains a tackifying resin, a surfactant, a plasticizer, a filler, a pigment, a dye, an antifoaming agent, an antiseptic, and an organic compound as long as the object of the present invention is not impaired. If desired, various additives such as a solvent may be contained.

Needless to say, the adhesive composition according to the first invention can be used not only for paper tubes but also for paper packaging, woodworking, general use and the like.

[0024]

The adhesive composition according to the first aspect of the present invention comprises a vinyl acetate resin emulsion in which 0.1 to 10 parts by weight of N-methylolacrylamide is copolymerized with 100 parts by weight of vinyl acetate monomer as a main component. , With excellent water resistance and initial adhesion.

Since the paper tube according to the second aspect of the invention is manufactured by using the adhesive composition obtained according to the first aspect of the invention, it has excellent water resistance, adhesive strength and pressure resistance.

[0026]

EXAMPLES In order to explain the present invention in more detail, examples will be given below. In addition, "part" in an Example means a "weight part."

(Example 1)

(1) Weight of vinyl acetate resin emulsion
A reaction vessel equipped with a combined stirrer, a reflux condenser, a thermometer and a dropping funnel was charged with 125 parts of water and 11 parts of polyvinyl alcohol (average degree of polymerization 1700, degree of saponification 96 mol%) and stirred at 95 ° C. for 1 hour. An aqueous solution of polyvinyl alcohol was obtained by heating. Next, this aqueous solution was cooled to 70 ° C., and 8 parts of vinyl acetate monomer, 0.24 part of N-methylolacrylamide and a polymerization catalyst (hydrogen peroxide of 0.1%) were added thereto.
Parts and 0.2 parts of tartaric acid) to carry out initial polymerization. Then, 92 parts of vinyl acetate monomer, 2.76 parts of N-methylol acrylamide and a polymerization catalyst (0.4 parts of hydrogen peroxide and 0.4 parts of tartaric acid) were added dropwise and emulsion polymerization was carried out at 70 ° C., and then 70 ° C. Aged for 1 hour at 47% solids
To obtain a vinyl acetate resin emulsion. In the above, N-methylolacrylamide used was dissolved in the same amount of water.

(2) Preparation of Adhesive Composition Solid content of the obtained vinyl acetate resin emulsion is 100
To 15 parts by weight, 15 parts of dibutyl phthalate (DBP) was added and mixed to obtain an adhesive composition.

(3) Evaluation The various properties of the obtained adhesive composition were evaluated by the following methods and the results are shown in Table 1. The evaluation was carried out in an atmosphere of 20 ° C.-65% RH unless otherwise specified.

Initial adhesive strength (shear adhesive strength) Two sheets of class B paper tube base paper (manufactured by Okayama Paper Co., Ltd.) cut into 25 mm × 50 mm were used as test pieces, and the obtained adhesive composition was applied to one surface of one of the test pieces. Immediately after applying a coating area of 25 mm x 25 mm and a coating amount of 0.05 g / (25 mm) ² .
Adhesive area of the other test piece is 25 mm
The pieces were alternately laminated to each other so as to have a size of 25 mm, and the bonded portions were clamped with a pressure of 1 kg / (25 mm) ² to prepare an adhesion test piece. The tensile shear strength of each adhesive test piece after 20 seconds and 40 seconds of pressing time was measured at a tensile speed of 10 mm / min using a Tensilon tester to determine the shear adhesive strength (kg / (25 mm) ² ). .

Initial adhesive strength (material breaking time) Two sheets of the same class B paper tube base paper cut to 20 mm × 40 mm were used as test pieces, and one surface of one of the test pieces was coated with the above adhesive composition on an area of 20 mm × 30mm, coating amount 40g
/ M ² and was applied so that, immediately bonded to the coated surface to the other test piece adhesive area becomes 20 mm × 30 mm, the bonding portions 70 g / cm ²
A large number of adhesion test pieces were prepared by pressing under the pressure of 5 seconds. Next, the adhesive test piece was peeled off by hand every 10 seconds after depressurization, and the fracture area ratio of the adhesive portion of the base paper for class B paper tube was 100%.
The shortest time (seconds) to reach was measured.

Water resistance (falling time) Two sheets of the same base paper for a class B paper tube cut to 25 mm × 50 mm were used as test pieces, and one surface of one test piece was coated with the above adhesive composition on an area of 25 mm × 25 mm, Coating amount 0.0
5 g / (25 mm) ² is applied, and one surface of the other test piece is alternately attached to this application surface so that the adhesive area is 25 mm × 25 mm, and 1 kg of this attached portion is applied.
/ (25mm) ^{2 After} pressure bonding for 60 seconds, 20 ℃
An adhesion test piece was prepared by curing for 8 hours in an atmosphere of −65% RH. At the lower end of one of the adhesion test pieces, 10
The weight (0 g) was suspended and vertically suspended in warm water of 60 ° C., and the time (minute) until the adhesive portion peeled off and dropped was obtained.

(Examples 2 to 5)

In the polymerization of the vinyl acetate resin emulsion, four kinds of vinyl acetate resin emulsions were obtained in the same manner as in Example 1 with the monomer compositions shown in Table 1. Using the four types of vinyl acetate resin emulsion obtained,
Four kinds of adhesive compositions were obtained in the same manner as in Example 1.

Various performances of the obtained four kinds of adhesive compositions were evaluated in the same manner as in Example 1 and the results are shown in Table 1.

(Comparative Example 1)

In the polymerization of the vinyl acetate-based resin emulsion, as shown in Table 1, the vinyl acetate-based resin emulsion was prepared in the same manner as in Example 1 except that the monomer composition was 100 parts of vinyl acetate monomer and N-methylolacrylamide was not used. A resin emulsion was obtained. An adhesive composition was obtained in the same manner as in Example 1 using the obtained vinyl acetate resin emulsion.

Various properties of the obtained adhesive composition were evaluated in the same manner as in Example 1 and the results are shown in Table 1.

(Comparative Examples 2-5)

In the polymerization of the vinyl acetate resin emulsion, four kinds of vinyl acetate resin emulsions were obtained with the monomer composition shown in Table 1 in the same manner as in Example 1. Using the four types of vinyl acetate resin emulsion obtained,
Four kinds of adhesive compositions were obtained in the same manner as in Example 1.

Various performances of the obtained four kinds of adhesive compositions were evaluated in the same manner as in Example 1 and the results are shown in Table 1.

(Comparative Example 6)

In the polymerization of the vinyl acetate resin emulsion, as shown in Table 1, the monomer composition was changed to 100 parts of vinyl acetate monomer and 1 part of N-methylol acrylamide.
Emulsion polymerization was carried out in the same manner as in Example 1 except that the amount was changed to 3 parts. However, since a large amount of aggregates were generated during emulsion polymerization, emulsion polymerization could be interrupted halfway to obtain a vinyl acetate resin emulsion. I could not do it.

[0045]

[Table 1]

[0046]

As described above, the adhesive composition according to the first invention has excellent water resistance and initial adhesive strength. or,
The paper tube according to the second aspect of the invention produced by using this has excellent water resistance, adhesive strength, pressure resistance and the like.

Claims (2)

[Claims] 1. 100 parts by weight of vinyl acetate monomer and N-
An adhesive composition comprising a vinyl acetate resin emulsion obtained by emulsion polymerization of 0.1 to 10 parts by weight of methylol acrylamide as a main component. 2. A paper tube characterized in that a strip-shaped paper piece is wound in a tubular shape, and a polymerized portion of the tubular paper piece wound in a tubular shape is adhered by the adhesive composition according to claim 1.