JPH07216333A - Adhesive composition and paper tube made therewith - Google Patents

Abstract

PURPOSE:To obtain an adhesive composition which has high film modulus, good initial tack and water resistance, suffers less from the settlement of the constituent inorganic filler and therefore has uniform properties and good workability. CONSTITUTION:This composition is prepared by adding 1-30 pts.wt. inorganic filler to 100 pts.wt. vinyl acetate resin emulsion obtained by emulsion- copolymerizing a vinyl acetate monomer with a vinylsilane monomer.

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, woodworking, paper packaging, and the like, and a method for producing the same using the adhesive composition. Related to 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 , Those based on one kind or two or more kinds of starch, polyvinyl alcohol, vinyl acetate resin and the like are known.

Generally, a paper tube adhesive is required to have good initial adhesiveness, water resistance, and high pressure resistance of the manufactured paper tube. In particular, in order to improve the pressure resistance of the paper tube, it is necessary to increase the elastic modulus of the dry film of the adhesive (hereinafter referred to as "film elastic modulus"). No rate was obtained.

As one method for increasing the film elastic modulus of a paper tube adhesive, a method has been proposed in which 10 to 30 parts by weight of clay, which is an inorganic filler, is mixed with 100 parts by weight of a vinyl acetate emulsion (special feature). In the case of this method, although the film elastic modulus is improved, when the viscosity of the adhesive is low, clay, which is an inorganic filler, sediments with the passage of time, and the adhesive lacks uniformity and adheres. There are problems that the variation in performance becomes large and the workability becomes poor.

[0005]

As described above, the conventional adhesives do not have a high film elastic modulus, good initial adhesiveness and water resistance, and thus are sufficiently used for paper tubes and the like. It was unbearable.

In view of the above points, the present invention has a high film elastic modulus, good initial adhesiveness and water resistance, and has almost no sedimentation of the inorganic filler and a uniform property and good workability. An object is to provide an adhesive composition containing a vinyl acetate resin emulsion as a main component and a paper tube using the same.

[0007]

The adhesive composition of the present invention is a vinyl acetate resin emulsion 1 obtained by emulsion copolymerizing a vinyl acetate monomer and a vinylsilane monomer.
It is characterized in that the inorganic filler is contained in an amount of 1 to 30 parts by weight with respect to 00 parts by weight, whereby the above object is achieved.

Further, the paper tube of the present invention is characterized in that the strip-shaped paper piece is wound in a tubular shape, and the polymerized portion of the tubular paper piece wound in the tubular shape is adhered by the above-mentioned adhesive composition. .

The vinyl acetate resin emulsion, which is the main component of the adhesive composition of the present invention, comprises vinyl acetate as a main component having a solid content of about 40 to 60% obtained by emulsion copolymerization of vinyl acetate monomer and vinylsilane monomer. Is an emulsion.

The ratio of the vinyl acetate monomer and the vinyl silane monomer used for emulsion polymerization of the vinyl acetate resin emulsion is not particularly limited, but 0.01 to 1 vinyl silane monomer is added to 100 parts by weight of the vinyl acetate monomer. About parts by weight is preferable, and 0.0
About 5 to 0.2 parts by weight is more preferable.

If the amount of the vinylsilane monomer is less than 0.01 parts by weight with respect to 100 parts by weight of the vinyl acetate monomer, precipitation of the inorganic filler will increase and water resistance will decrease. On the other hand, when the amount of the vinylsilane monomer exceeds 1 part by weight, the stability during emulsion polymerization decreases.

Further, in the present invention, one or more ethylenically unsaturated monomers copolymerizable with vinyl acetate monomer and vinylsilane monomer other than vinyl acetate monomer and vinylsilane monomer are optionally copolymerized during emulsion polymerization of the above vinyl acetate resin emulsion. May be polymerized.

The above ethylenically unsaturated monomers include
(Meth) acrylic acid, methyl (meth) acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, ethylene glycol di (meth) acrylate, glycidyl (meth) acrylate, ethylene glycol mono (meth) acrylate, propylene glycol (meth) Acrylate etc. are mentioned.

The method for producing the vinyl acetate resin emulsion, which is the main component of the adhesive composition of the present invention, is not a special method. For example, an aqueous solution of polyvinyl alcohol or an aqueous solution of carboxymethyl cellulose is used as a protective colloid, and persulfate is used. Using vinyl acetate monomer and vinylsilane monomer or vinyl acetate monomer, vinylsilane monomer and one or more of the above ethylenically unsaturated monomers as a polymerization catalyst using a salt, a peroxide, etc. at a temperature of about 60 to 80 ° C. for 1 to 4 hours. It can be obtained by emulsion polymerization.

In the adhesive composition of the present invention, the type of the inorganic filler contained in the vinyl acetate resin emulsion is not particularly limited, and is generally calcium carbonate, clay, talc, calcium oxide, titanium oxide or the like. Inorganic fillers are preferably used.

In the present invention, the blending amount of the above-mentioned inorganic filler with respect to 100 parts by weight of the vinyl acetate resin emulsion must be in the range of 1 to 30 parts by weight. 10
More preferably, it is in the range of 25 parts by weight.

If the blending amount of the inorganic filler is less than 1 part by weight with respect to 100 parts by weight of the vinyl acetate resin emulsion, the film elastic modulus of the obtained adhesive composition is not improved, and conversely 3
When it exceeds 0 parts by weight, the initial adhesiveness of the obtained adhesive composition is lowered and the precipitation of the inorganic filler is increased.

The method of blending the inorganic filler with the vinyl acetate resin emulsion is not particularly limited,
A predetermined amount of an inorganic filler may be directly mixed and dispersed in the vinyl acetate resin emulsion, or a slurry liquid in which the inorganic filler is dispersed in water is prepared in advance, and the slurry liquid and the vinyl acetate resin emulsion are prepared. However, the latter method is more preferable in consideration of easiness of mixing and uniformity.

If desired, the adhesive composition of the present invention may contain additives such as tackifying resins, plasticizers, defoamers, preservatives and pigments.

[0020]

The adhesive composition of the present invention contains 1 to 30 parts by weight of an inorganic filler based on 100 parts by weight of a vinyl acetate resin emulsion obtained by emulsion-copolymerizing a vinyl acetate monomer and a vinylsilane monomer. Vinyl silane, which is contained and copolymerized with vinyl acetate monomer, exerts a coupling effect that binds both the vinyl acetate resin, which is the main component, and the inorganic filler, and prevents the inorganic filler from settling. The agent composition becomes more uniform, and high film elastic modulus, excellent initial adhesion, water resistance and the like can be obtained.

[0021]

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) Preparation of Adhesive Composition A reaction vessel equipped with a stirrer, a reflux condenser, a thermometer and a dropping funnel was charged with 115 parts of water and polyvinyl alcohol (saponification degree: 9).
10 parts of 6 mol% and a polymerization degree of 1700) were charged and stirred to disperse polyvinyl alcohol in water. This dispersion was heated to 90 ° C. and kept at the same temperature for 1 hour to dissolve polyvinyl alcohol. Next, this aqueous solution of polyvinyl alcohol was cooled to 75 ° C., 10 parts of vinyl acetate monomer and 0.01 part of vinyl silane monomer, 0.06 part of hydrogen peroxide as a polymerization initiator and 0.04 part of tartaric acid were added to the initial solution. Polymerization was carried out. Next, 90 parts of vinyl acetate monomer and 0.09 part of vinyl silane monomer, 0.24 part of hydrogen peroxide and 0.16 of tartaric acid were added dropwise over 3 hours to carry out emulsion polymerization, followed by aging at 80 ° C. for 1 hour and cooling. As a result, a vinyl acetate resin emulsion having a solid content of 47% and a viscosity at 20 ° C. of 7,000 cps was obtained. Calcium carbonate "Brivianto 1500" (manufactured by Shiraishi Industry Co., Ltd.) as a filler for 100 parts of the obtained vinyl acetate resin emulsion.
5 parts, 3 parts of plasticizer "PHP" (manufactured by Yokkaichi Gosei Co., Ltd.) and 22 parts of water were added and mixed to obtain an adhesive composition having a solid content of 42% and a viscosity of 850 cps at 20 ° C.

( 2) Evaluation The film elastic modulus, initial adhesion, water resistance and sedimentation of the inorganic filler 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.

Coating elastic modulus An adhesive composition was applied onto a polyethylene plate, and the temperature was 20 ° C.-6.
300 obtained by curing for 3 days in an atmosphere of 5% RH
A dry film having a thickness of ˜500 μm was punched out with a No. 1 dumbbell to prepare a test piece. Then, this test piece is 20 ° C.-65%
After conditioning the humidity for 24 hours in an RH atmosphere, it was set in a tensile tester and pulled at a pulling speed of 10 mm / min.
% Tensile strength and elongation, the film elastic modulus (kg / c
m ² ) was calculated.

Initial adhesiveness Two pieces of Class B paper tube base paper (manufactured by Okayama Paper Co., Ltd.) cut into a width of 20 mm and a length of 40 mm were used as test pieces, and one surface of one of the test pieces was coated with the adhesive composition with an area of 20 mm × Immediately after coating with 30 mm and a coating amount of 30 g / m ² , one surface of the other test piece was bonded to this coated surface so that the bonding area was 20 mm × 30 mm, and the bonded portion was 70 g / c.
A large number of adhesion test pieces were prepared by pressing for 5 seconds with a pressure of m ² . Then, the adhesive test piece is peeled by hand every 10 seconds after depressurization, and the broken state of the base paper at the peeled portion is observed, and the initial adhesiveness (second) is taken with the shortest time until the broken area ratio reaches 100%.
And

Two sheets of Class B paper tube base paper (manufactured by Okayama Paper Co., Ltd.) cut into a water-resistant width of 25 mm and a length of 120 mm were used as test pieces, and one surface of one test piece was coated with the adhesive composition on an area of 25 mm × 50 mm. After coating with a coating amount of 80 g / m ² , one surface of the other test piece was bonded so that the bonding area was 25 mm × 50 mm, and the bonded portion was clamped at a pressure of 1 kg / 25 mm ² for 60 seconds. , An adhesive test piece was prepared by curing for 24 hours in an atmosphere of 20 ° C.-65% RH. Then, one of the adhesion test pieces was bent in a 180 degree angle peeling direction, a weight of 100 g was hung at the lower end and vertically suspended in warm water of 60 ° C., and the water resistance was measured with the shortest time until the bonded portion peeled off and dropped. Sex (time).

Sedimentability of Inorganic Filler 65 g of the adhesive composition was placed in a test tube having a diameter of 20 mm and a depth of 400 mm, and the amount of sedimentation of the inorganic filler after standing still in an atmosphere of 20 ° C.-65% RH for 1 week (G) was measured to determine the sedimentation rate (%) with respect to the total amount of the inorganic filler in the adhesive composition.

(Examples 2-3, Comparative Examples 1-3)

Five types of adhesive compositions having the compositions shown in Table 1 were prepared in the same manner as in Example 1.

Table 1 shows the results of evaluation of the film elastic modulus, the initial adhesion, the water resistance and the sedimentation of the inorganic filler of the obtained five kinds of adhesive compositions in the same manner as in Example 1. It was

[0031]

[Table 1]

As shown in Table 1, the adhesive compositions of Examples 1 to 3 according to the present invention have a high film elastic modulus, good initial adhesion and water resistance, and a low sedimentation rate of the inorganic filler. In contrast, the adhesive composition of Comparative Example 1 has a low film elastic modulus, and the adhesive composition of Comparative Example 2 has poor water resistance and a high sedimentation rate of the inorganic filler. In addition, the adhesive composition of Comparative Example 3 has poor water resistance, lacks practicality, and has a high sedimentation rate of the inorganic filler.

[0033]

As described above, the adhesive composition according to the present invention has a high film elastic modulus, good initial adhesiveness and water resistance, and almost no sedimentation of the inorganic filler. It is preferably used for paper, paper packaging and the like. Further, the paper tube manufactured using this is excellent in pressure resistance and water resistance.

Claims (2)

[Claims] 1. An inorganic filler is contained in an amount of 1 to 30 relative to 100 parts by weight of a vinyl acetate resin emulsion obtained by emulsion copolymerizing a vinyl acetate monomer and a vinylsilane monomer.
An adhesive composition characterized by being contained in a range of parts by weight. 2. A paper tube, wherein a strip-shaped paper strip is wound in a tubular shape, and the polymerized portion of the tubular strip-shaped paper strip is adhered by the adhesive composition according to claim 1.