JPH09263741A - Adhesive composition and paper tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive compsn. which has good initial adhesive properties and forms a film with a high elastic modulus and to provide a paper tube made using the same. SOLUTION: This compsn. comprises a vinyl acetate resin emulsion obtd. by the emulsion polymn. of vinyl acetate alone or together with another ethylenically unsatd. monomer. The polymn. is conducted in the presence of an aq. soln. selected from among aq. solns of poly (N-vinylacetamide), polyacrylic acid, its salt, polyvinylpyrrolidone, a copolymer of styrene and maleic anhydride a copolymer of styrene, maleic anhydride, and another ethylenically unsatd. monomer, and its salt. A paper tube is made by rolling a strip of paper into a tubular from by using the compsn. for bonding the parts of the strip laid one on top of another.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an adhesive composition having excellent initial adhesiveness and a high film elastic modulus, and a paper tube using the same.

[0002]

BACKGROUND OF THE INVENTION Adhesives are widely used in various fields such as paper tubes, woodworking, and paper packaging. An adhesive composition that constitutes such an adhesive is required to have high elasticity as well as strong adhesiveness and excellent workability.

The paper tube is constructed by winding a strip of paper around a metal core in a plurality of layers, and adhering the polymerized portion of the strip of paper with an adhesive. Therefore, the adhesive composition constituting the adhesive used therein is required to have excellent initial adhesiveness. In addition, the manufactured paper tube is required to have high pressure resistance. 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”).

[0004] As such an adhesive composition which has been conventionally used, one of starch aqueous solution, polyvinyl alcohol aqueous solution, vinyl acetate resin emulsion, etc. has been used.
There are types based on two or more species. However, these adhesive compositions cannot always obtain a sufficient film elastic modulus.

As an adhesive composition having an increased film elastic modulus,
Japanese Unexamined Patent Publication (Kokai) No. 1-234484 discloses a mixture of vinyl acetate emulsion with clay as an inorganic filler. However, this one improves the film elastic modulus, but when the viscosity of the adhesive composition is low,
Over time, clay settles and the components become non-uniform. Therefore, adhesion failure occurs and the workability deteriorates, so that it cannot be used as a paper tube adhesive.

[0006]

SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to provide an adhesive composition having a high film elastic modulus and good initial adhesiveness, and a paper tube using the same. .

[0007]

The adhesive composition of the present invention is a vinyl acetate-based composition obtained by emulsion-polymerizing a vinyl acetate monomer or the vinyl acetate monomer and another ethylenically unsaturated monomer. An adhesive composition comprising a resin emulsion, wherein the emulsion polymerization comprises an aqueous solution of poly (N-vinylacetamide) (a), an aqueous solution of polyacrylic acid or a salt thereof (b), an aqueous solution of polyvinylpyrrolidone (c), And one selected from the group consisting of a copolymer of styrene and maleic anhydride or a copolymer of styrene, maleic anhydride and another ethylenically unsaturated monomer, or an aqueous solution (d) of a salt thereof. It is characterized in that it was carried out in the presence of the aqueous solution.

The paper tube of the present invention is characterized by using the above-mentioned adhesive composition for adhering the polymerized portion of the strip-shaped paper piece. Hereinafter, the present invention will be described in detail.

The adhesive composition of the present invention comprises a vinyl acetate resin emulsion obtained by emulsion-polymerizing a vinyl acetate monomer or the above vinyl acetate monomer and another ethylenically unsaturated monomer.

The ethylenically unsaturated monomer is not particularly limited, and examples thereof include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate,
Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, ethylene glycol di (meth) acrylate, glycidyl (meth) acrylate and the like can be mentioned.

In the present invention, the emulsion polymerization is carried out with an aqueous solution of poly (N-vinylacetamide) (a), an aqueous solution of polyacrylic acid or a salt thereof (b), an aqueous solution of polyvinylpyrrolidone (c), and styrene. Presence of one aqueous solution selected from the group consisting of an aqueous solution (d) of a copolymer comprising maleic anhydride or a copolymer comprising styrene, maleic anhydride and another ethylenically unsaturated monomer, or a salt thereof. Do it below.

Content of poly (N-vinylacetamide) in the aqueous solution (a), content of polyacrylic acid or its salt in the aqueous solution (b), content of polyvinylpyrrolidone in the aqueous solution (c). The content of the copolymer composed of styrene and maleic anhydride or the copolymer composed of styrene, maleic anhydride and another ethylenically unsaturated monomer in the aqueous solution (d) or a salt thereof is
The amount of the vinyl acetate monomer and the ethylenically unsaturated monomer is preferably 5 to 50 parts by weight based on 100 parts by weight in total. If it is less than 5 parts by weight, the resulting adhesive composition cannot exhibit a sufficient film elastic modulus, and if it exceeds 50 parts by weight, the viscosity increases during the polymerization, and in extreme cases, gel. Turn into.

The emulsion polymerization method is not particularly limited, and for example, it can be carried out by a conventionally known method using a polymerization initiator such as hydrogen peroxide, potassium persulfate or ammonium persulfate. Moreover, you may use well-known polyvinyl alcohol, an emulsifier, etc. together if needed.

If desired, additives such as antifoaming agents, preservatives, plasticizers, fillers and pigments can be added to the adhesive composition of the present invention.

In the present invention, the above poly (N-vinylacetamide), which is a polymer having a relatively high elastic modulus, the above polyacrylic acid or a salt thereof, the above polyvinylpyrrolidone, or the above styrene and maleic anhydride or styrene, anhydrous Since emulsion polymerization is carried out in the presence of a copolymer of maleic acid and other ethylenically unsaturated monomers or a salt thereof, the film elastic modulus of the vinyl acetate resin emulsion obtained does not require addition of an inorganic filler. It will be high enough.

The paper tube of the present invention is a paper tube formed by winding a strip-shaped paper strip in a tubular shape, and the polymerized portion of the strip-shaped paper strip is adhered by the adhesive composition of the present invention.

[0017]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 In a reactor equipped with a stirrer, a thermometer, a reflux condenser and a dropping funnel, 65 parts by weight of water, poly (N-vinylacetamide) aqueous solution (GE-191, solid content concentration 20% by weight, Showa Denko). (Manufactured by K.K.) 75 parts by weight was charged and the temperature was raised to 70 ° C. Next, 8 parts by weight of vinyl acetate monomer, 0.2 parts by weight of acrylic acid, and a polymerization initiator (0.1 parts by weight of hydrogen peroxide and 0.2 parts by weight of tartaric acid) were added to carry out initial polymerization. Thereafter, 92 parts by weight of vinyl acetate monomer and acrylic acid of 0.
8 parts by weight and a polymerization initiator (0.4 parts by weight of hydrogen peroxide and 0.4 parts by weight of tartaric acid) were added dropwise, and the reaction temperature was 70 ° C.
After completion of the dropwise addition, the mixture was aged at 70 ° C. for 1 hour after completion of the dropping to obtain a vinyl acetate resin emulsion having a solid content concentration of 48% by weight.

An antifoaming agent and a preservative were further added to the obtained vinyl acetate resin emulsion to obtain an adhesive composition containing the vinyl acetate resin emulsion as a main component. The film elastic modulus and initial adhesiveness of the obtained adhesive composition were evaluated by the following methods. The results are shown in Table 1.

Evaluation method 1. Coating elastic modulus The obtained adhesive composition was applied onto a polyethylene plate, and 2
It was aged in an atmosphere of 0 ° C. × 65% RH for 3 days, and the obtained dry film having a thickness of 300 to 500 μm was punched out with a No. 1 dumbbell to prepare a test piece. The obtained test piece is 20 ° C.
After conditioning the humidity for 24 hours in an atmosphere of 65% RH, then at 20 ℃
The film elastic modulus (kg / cm ² ) was determined from the tensile strength and the elongation rate at an elongation rate of 10% in a 65% RH atmosphere using a tensile tester at a tensile rate of 10 mm / min.

2. Initial Adhesion Two sheets of base paper for class B paper tubes (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 the adhesive composition obtained on one side of the base paper was applied with an application area of 20 × 30 mm. After coating so as to obtain two pieces of base paper, the pieces were stuck together and pressed at a pressure of 70 g / cm ² for 5 seconds to prepare a large number of test pieces. Next, after depressurization, the obtained test piece was peeled by hand every 10 seconds, the broken state of the base paper at the peeled portion was observed, and the shortest time until the broken area ratio reached 100% was the initial adhesiveness ( Seconds).

Example 2 Poly (N-vinylacetamide) aqueous solution (GE-19
1. An adhesive composition was obtained and evaluated in the same manner as in Example 1 except that 150 parts by weight of solid content concentration 20% by weight, Showa Denko KK) and 60 parts by weight of water were used. The results are shown in Table 1. The solid content concentration of the obtained vinyl acetate resin emulsion was 42% by weight.

Example 3 Poly (N-vinylacetamide) aqueous solution (GE-19
1, a solid content concentration of 20% by weight, manufactured by Showa Denko KK, instead of an aqueous solution of sodium polyacrylate (Synacner A-8)
18, solid content concentration 40% by weight, manufactured by San Nopco) 3
An adhesive composition was obtained and evaluated in the same manner as in Example 1 except that 7.5 parts by weight and 100 parts by weight of water were used. The results are shown in Table 1. The solid content concentration of the obtained vinyl acetate resin emulsion was 48% by weight. The results are shown in Table 1.

Example 4 Sodium polyacrylate aqueous solution (Synakner A-81
No. 8, solid content concentration 40% by weight, manufactured by San Nopco) was 75 parts by weight and water was 134 parts by weight, and an adhesive composition was obtained and evaluated in the same manner as in Example 3. The results are shown in Table 1. The solid content concentration of the obtained vinyl acetate resin emulsion was 42% by weight.

Example 5 A reactor equipped with a stirrer, a thermometer, a reflux condenser and a dropping funnel was charged with 125 parts by weight of water and polyvinylpyrrolidone (K-3).
0, average molecular weight 40,000, manufactured by ISP Co.) 15 parts by weight were charged and the polyvinylpyrrolidone was dispersed in water by stirring. This dispersion was heated to 90 ° C. and kept at the same temperature for 1 hour to obtain an aqueous polyvinylpyrrolidone solution.

The obtained polyvinylpyrrolidone aqueous solution was added to 7
After cooling to 0 ° C., 8 parts by weight of vinyl acetate monomer, 0.2 parts by weight of acrylic acid, and a polymerization initiator (hydrogen peroxide 0.1
Parts by weight and tartaric acid (0.2 parts by weight) were added to carry out initial polymerization. Then, 92 parts by weight of vinyl acetate monomer, 0.8 parts by weight of acrylic acid, and a polymerization initiator (0.4 parts by weight of hydrogen peroxide and 0.4 parts by weight of tartaric acid) were added dropwise to polymerize at a reaction temperature of 70 ° C. After completion of the dropping, the mixture was aged at a temperature of 70 ° C. for 1 hour to obtain a vinyl acetate resin emulsion having a solid content concentration of 48% by weight.

An antifoaming agent and an antiseptic agent were further added to the obtained vinyl acetate resin emulsion to obtain an adhesive composition containing the vinyl acetate resin emulsion as a main component. The obtained adhesive composition was evaluated in the same manner as in Example 1. The results are shown in Table 1.

Example 6 Polyvinylpyrrolidone (K-30, average molecular weight 40,000, I
Polyvinylpyrrolidone (K-1) instead of SP
5, an average molecular weight of 10,000, manufactured by ISP) was 30 parts by weight and water was 175 parts by weight, and an adhesive composition was obtained and evaluated in the same manner as in Example 5. The results are shown in Table 1. The solid content concentration of the obtained vinyl acetate resin emulsion was 45% by weight.

Example 7 Polyvinylpyrrolidone (K-30, average molecular weight 40,000, I
Polyvinylpyrrolidone (K-6) instead of SP
0, average molecular weight 220,000, manufactured by ISP), 110 parts by weight,
An adhesive composition was obtained and evaluated in the same manner as in Example 5 except that the amount of water was 133 parts by weight. The results are shown in Table 1. The solid content concentration of the obtained vinyl acetate resin emulsion was 45% by weight.

Example 8 Polyvinylpyrrolidone (K-30, average molecular weight 40,000, I
Polyvinylpyrrolidone (K-9) instead of SP
0, average molecular weight 1.2 million, manufactured by ISP) was 6 parts by weight and water was 152 parts by weight, and an adhesive composition was obtained and evaluated in the same manner as in Example 5. The results are shown in Table 1.
The solid content concentration of the obtained vinyl acetate resin emulsion was 40% by weight.

Example 9 Poly (N-vinylacetamide) aqueous solution (GE-19
1. Solid content concentration 20% by weight, manufactured by Showa Denko KK. Instead of an aqueous solution of sodium salt of a copolymer consisting of styrene, maleic anhydride and methyl methacrylate (Caribbon B, solid content concentration 40% by weight, Sanyo Chemical Industries) 3)
An adhesive composition was obtained and evaluated in the same manner as in Example 1 except that 7.5 parts by weight and 100 parts by weight of water were used. The results are shown in Table 1. The solid content concentration of the obtained vinyl acetate resin emulsion was 48% by weight.

Example 10 An aqueous solution of sodium salt of a copolymer consisting of styrene, maleic anhydride and methyl methacrylate (Caribbon B, solid content concentration 40% by weight, manufactured by Sanyo Kasei Co., Ltd.) was used.
Example 9 except that the parts by weight and water were set to 134 parts by weight.
An adhesive composition was obtained and evaluated in the same manner as. Table 1 shows the results
It was shown to. The solid content concentration of the obtained vinyl acetate resin emulsion was 42% by weight.

Comparative Example 1 Poly (N-vinylacetamide) aqueous solution (GE-19
1. Adhesive composition was obtained and evaluated in the same manner as in Example 1 except that 15 parts by weight of solid content concentration 20% by weight, Showa Denko KK) and 112 parts by weight of water were used. The results are shown in Table 1. The solid content concentration of the obtained vinyl acetate resin emulsion was 48% by weight.

Comparative Example 2 Poly (N-vinylacetamide) aqueous solution (GE-19
Polymerization was performed in the same manner as in Example 1 except that the solid content concentration was 20% by weight and Showa Denko KK) was 300 parts by weight. However, the viscosity of the system became extremely high during the polymerization, and the polymerization was abandoned. did.

Comparative Example 3 Sodium polyacrylate aqueous solution (Synakner A-81
8, solid concentration 40% by weight, San Nopco) 7.5
Example 3 except that the weight part and water were 108 parts by weight.
An adhesive composition was obtained and evaluated in the same manner as. Table 1 shows the results
It was shown to. The solid content concentration of the obtained vinyl acetate resin emulsion was 48% by weight.

Comparative Example 4 Sodium polyacrylate aqueous solution (Synakner A-81
8, solid content concentration 40% by weight, manufactured by San Nopco) 150
Example 3 except that the weight part and the water were 152 parts by weight.
Polymerization was carried out in the same manner as above, but the viscosity of the system became extremely high during the polymerization, and the polymerization was abandoned.

Comparative Example 5 Polyvinylpyrrolidone (K-30, average molecular weight 40,000, I
An adhesive composition was obtained and evaluated in the same manner as in Example 5 except that 3 parts by weight of SP) and 101 parts by weight of water were used. The results are shown in Table 1. The solid content concentration of the obtained vinyl acetate resin emulsion was 48% by weight.

Comparative Example 6 Polyvinylpyrrolidone (K-30, average molecular weight 40,000, I
Polymerization was carried out in the same manner as in Example 5 except that 60 parts by weight of SP) and 287 parts by weight of water (solid content concentration was set to 40% by weight) were used. Became extremely high, and the polymerization was abandoned.

Comparative Example 7 An aqueous solution of sodium salt of a copolymer consisting of styrene, maleic anhydride and methyl methacrylate (Caribbon B, solid content concentration 40% by weight, manufactured by Sanyo Chemical Industry Co., Ltd.) was used.
An adhesive composition was obtained and evaluated in the same manner as in Example 9 except that 5 parts by weight and 108 parts by weight of water were used. The results are shown in Table 1. The solid content concentration of the obtained vinyl acetate resin emulsion was 48% by weight.

Comparative Example 8 An aqueous solution of sodium salt of a copolymer consisting of styrene, maleic anhydride and methyl methacrylate (Caribbon B, solid content concentration 40% by weight, manufactured by Sanyo Chemical Industry Co., Ltd.) was used.
Polymerization was performed in the same manner as in Example 9 except that 0 part by weight and 152 parts by weight of water were used, but the viscosity of the system became extremely high during the polymerization, and the polymerization was abandoned.

Comparative Example 9 Poly (N-vinylacetamide) aqueous solution (GE-19
1. Adhesive composition in the same manner as in Example 1 except that an aqueous solution of polyvinyl alcohol (saponification degree: 96 mol%, polymerization degree: 1700) was used in place of the solid content concentration of 20% by weight, manufactured by Showa Denko KK Obtained and evaluated. The results are shown in Table 1. The solid content concentration of the obtained vinyl acetate resin emulsion was 48% by weight.

[0042]

[Table 1]

[0043]

Since the adhesive composition of the present invention has the above-mentioned constitution, it has a high film elastic modulus and is excellent in workability and initial adhesiveness, and is suitable for paper tubes, woodworking, paper packaging, etc. Can be preferably used in various fields. Further, the paper tube obtained by using the adhesive composition of the present invention has excellent pressure resistance.

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Claims (2)

[Claims] 1. A vinyl acetate monomer, or the vinyl acetate monomer and another ethylenically unsaturated monomer,
An adhesive composition comprising a vinyl acetate-based resin emulsion obtained by emulsion polymerization, wherein the emulsion polymerization comprises an aqueous solution of poly (N-vinylacetamide) (a),
An aqueous solution (b) of polyacrylic acid or a salt thereof, an aqueous solution (c) of polyvinylpyrrolidone, and a copolymer of styrene and maleic anhydride or styrene, maleic anhydride and another ethylenically unsaturated monomer. An adhesive composition characterized by being prepared in the presence of one aqueous solution selected from the group consisting of an aqueous solution (d) of a copolymer or a salt thereof. 2. A paper tube formed by winding a strip-shaped paper strip in a tubular shape, wherein the polymerized portion of the strip-shaped paper strip is adhered by the adhesive composition according to claim 1.