JPH05320603A - Hot-melt adhesive composition and paper product - Google Patents

Abstract

PURPOSE:To obtain an adhesive compsn. which hardly causes phase separation upon melting and has low structural viscosity and improved melt stability and coatability by melt mixing a specific polyvinyl alcohol resin with a tackifying resin. CONSTITUTION:This compsn. is prepd. by melt mixing 100 pts.wt. polyvinyl alcohol resin having an average degree of polymn. of 50-600 and a degree of saponification of 20-80mol% with 150 pts.wt. or lower terpene phenol-based or ketone-based tackifying resin having an acid value of 50 or lower and the mean number of hydroxyl groups per molecule of 1.5 or higher. The compsn. is applied to one surface of a substrate tape or adhered to form an adhesive layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyvinyl alcohol (hereinafter abbreviated as PVA) water-soluble or water-dispersible hot melt adhesive composition, and a paper product having an adhesive layer formed by the adhesive composition. For more details regarding
A hot-melt adhesive composition suitable for applications such as bookbinding, packaging, bag making, paper tube, heat-sensitive tape or label, rewetting tape or label, and an adhesive layer that can be recycled as waste paper It relates to a formed paper product.

[0002]

2. Description of the Prior Art PVA is adhesive by itself,
A tackifying resin or the like is blended for wider control of adhesiveness and control of heat and humidity resistance. At this time, when a compounding agent having poor compatibility with PVA is used, phase separation or structural viscosity occurs during melting of the adhesive composition, which impairs melt stability and coatability of the adhesive. Therefore, compounding agents other than PVA are P
It is important that the compatibility with VA is excellent.

However, in the past, Japanese Patent Laid-Open No. 51-89538 has been proposed.
JP-A No. 51-97650 and JP-A No. 51-97650 disclose that the average degree of polymerization is 100 to 1000 and the degree of saponification is 60 to 90 mol%.
To the PVA, and a softening point of 60~150 ℃ C ₄ ~C ₆ petroleum resin, aromatic petroleum resin and (or) hot melt adhesives formulated with hydrogenated products thereof have been proposed.

[0004]

However, these hot melt adhesives include PVA, C _{4 to} C ₆ petroleum-based resins having a softening point of 60 to 150 ° C. as a compounding agent, aromatic petroleum-based resins and ( Or) There is a problem that the compatibility with the hydrogenated product is still insufficient and the adhesiveness and the like are not sufficiently improved.

The present invention solves the above-mentioned conventional problems, is excellent in compatibility, is excellent in melt stability and the like, and is a water-soluble or water-dispersible hot melt adhesive composition, and is sufficiently soluble in water. It does not cause problems such as clogging of the wire of papermaking in the used paper collection process, such as paper products with a conventional hot melt adhesive layer that does not disperse or disperse, and can be recycled as used paper. With the aim of providing a paper product having an adhesive layer that can be formed, as a result of various experiments, a tackifying resin having a specific acid value, and
Terpene phenol-based tackifying resins having a specific average number of hydroxyl groups per molecule and ketone-based tackifying resins have excellent compatibility with PVA-based resins, and by blending them, melt stability, coating properties, water A hot-melt adhesive composition with excellent dispersibility, etc., and an adhesive layer that does not cause adhesive problems in recycled paper products and does not leave adhesive fragments in recycled paper products. It has been completed with the knowledge that the paper products that have been made can be obtained.

[0006]

According to the invention of claim 1 of the present application, a tackifying resin having an acid value of 50 or more is blended with a PVA resin having an average degree of polymerization of 50 to 600 and a degree of saponification of 20 to 80 mol%. It is a hot-melt adhesive composition containing a main component.

According to the invention of claim 2 of the present application, the average degree of polymerization is 50.
-600, a PVA resin having a saponification degree of 20 to 80 mol% and a hot melt adhesive containing a terpene phenol tackifying resin having an average number of hydroxyl groups per molecule of 1.5 or more as a main component It is a composition.

According to the invention of claim 3 of the present application, the average degree of polymerization is 50.
It is a hot-melt adhesive composition containing as a main component a mixture of a PVA resin having a saponification degree of 20 to 80 mol% and a ketone tackifying resin.

The invention according to claim 4 of the present application is a paper product having an adhesive layer formed of the hot-melt adhesive composition according to claim 1, claim 2 or claim 3.

In the present invention, the PVA resin is
An average degree of polymerization of 50 to 600, preferably 70 to 400, and a degree of saponification of 20 to 80 mol%, preferably 40 to 70 mol% are used.

When the average degree of polymerization of the PVA-based resin is less than 50, the adhesive strength is lowered, and when the saponification degree is less than 20 mol%, the water solubility or water dispersibility of the adhesive composition is lowered. On the other hand, when the average degree of polymerization exceeds 600 or the degree of saponification exceeds 80 mol%, the melt viscosity of the adhesive composition becomes extremely high, which makes coating difficult. If a large amount of a plasticizer for PVA is added, the viscosity can be lowered, but the cohesive force at high temperature and high humidity is significantly reduced.

Examples of the PVA-based resin include, in addition to PVA, PVA-based resins modified with organic acids such as carboxylic acids and sulfonic acids, saturated fatty acids such as vinyl versatate, and the like. PVA or modified PVA-based resins include Several types may be mixed and PVA and modified PVA-based resin may be used at the same time.

The tackifying resin used in the invention of claim 1 of the present application has an acid value of 50 or more. Specifically, it is a rosin-modified maleic acid resin and its modified product, or a rosin-modified special synthetic resin. , Rosin phenol resin and its modified products are used.

When the acid value is less than 50, the compatibility with the PVA type resin becomes poor. The preferable range of the mixing ratio is P
It is 150 parts by weight or less based on 100 parts by weight of the VA resin. Moreover, you may mix | blend other tackifying resin in the range compatible with PVA-type resin as needed.

The tackifying resin used in the second aspect of the present invention has an average number of hydroxyl groups per molecule of 1.5.
One or more terpene phenol-based tackifying resins, for example, reaction products of α-pinene, β-pinene and the like with phenols such as phenol and bisphenol. The average number of hydroxyl groups per molecule of the terpene phenol-based tackifying resin can be calculated from the blending ratio of the reaction resin components blended to obtain the reaction product.

When the average number of hydroxyl groups per molecule is less than 1.5, the compatibility with PVA-based resin becomes poor. The suitable range of the blending ratio is 150 parts by weight or less with respect to 100 parts by weight of the PVA-based resin. Also, if necessary,
Other tackifying resins may be blended within the range of compatibility.

The ketone-based tackifying resin used in the invention of claim 3 of the present application is, for example, a reaction product of a ketone such as cyclohexanone and formaldehyde. The suitable range of the blending ratio is 150 parts by weight or less with respect to 100 parts by weight of the PVA-based resin. If necessary, another tackifying resin may be added within the range of compatibility.

Other tackifying resins include, for example:
Rosin and its derivative, polymerized rosin resin and its derivative, disproportionated rosin resin and its derivative, polyterpene resin, alkylphenol resin, coumarone-indene resin, xylene resin, aliphatic hydrocarbon resin and its hydrogenated product, alicyclic carbonization Examples thereof include hydrogen resins, aromatic hydrocarbon resins and hydrogenated products thereof, styrene resins, vinyltoluene-α-methylstyrene copolymers, alkylphenol resins and the like.

The hot melt adhesive composition of the present invention comprises
In order to broadly improve various physical properties such as flexibility, blocking resistance, coatability, heat resistance, thermal stability when melted, water solubility, and water dispersibility, a plasticizer for PVA and If necessary, an organic or inorganic substance that is usually used as a component of a hot melt adhesive composition, for example, a thermoplastic resin, a wax, an antioxidant, a filler, a dye / pigment or the like may be added.

As the plasticizer for PVA, one having good compatibility with the PVA resin is used. Examples of such plasticizers include glycerin, polyglycerin (dimer or more), trimethylolethane, trimethylolpropane, pentaerythritol, ethylene glycol, propanediol, butanediol, hexanediol,
Polyethylene glycol, 3-methylpentane-1,
Polyhydric alcohols such as 3,5 triol, xylit, xylol, arabite, adnit, mannitol, sorbit, and dulcit, or higher fatty acid esters thereof, and addition products thereof with ethylene oxide or propylene oxide, ethylene urea, etc. Examples thereof include urea derivatives. In addition, phthalate such as dioctyl phthalate and dicyclohexyl phthalate, benzoate such as glyceroyl tribenzoate and neopentyl glycol dibenzoate, phosphorus such as triphenyl phosphite, fatty acid such as dioctyl sebacate and dioctyl adipate, polyester etc. Plasticizers are used.

Examples of the thermoplastic resin include polyethylene, polypropylene, ethylene-propylene copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer and its derivatives, ethylene-acrylic acid copolymer, ethylene-methacrylic acid. Copolymer, ethylene-acrylic acid ester copolymer, ethylene-vinyl acetate-organic acid copolymer and its derivatives, ethylene-propylene-organic acid copolymer and its derivatives, polyester, polyurethane, polyamide, butyl rubber, styrene- A butadiene block copolymer and its partially hydrogenated product, a styrene-isoprene block copolymer and its partially hydrogenated product, etc. are used.

As the wax, for example, paraffin wax, microcrystalline wax, low molecular weight polyethylene wax, oxidized polyethylene wax and the like are used.

As the antioxidant, for example, phenol-based, amine-based, phosphorus-based, phosphoric acid-based antioxidants and the like are used.

As the filler, for example, calcium carbonate, clay, talc, mica powder, barium sulfate, zinc oxide, magnesium oxide, hydrous silicic acid, silicic acid anhydride and the like are used.

As the dye / pigment, for example, titanium oxide, ultramarine blue, and phthalocyanine dyes are preferable. These optional additional components may be used alone or in combination of two or more.

The hot melt adhesive composition of the present invention is prepared by a conventional method as described below. That is, the above components are blended in a predetermined blending ratio, and the blend is melt-mixed to form a uniform mixed composition to obtain a hot melt adhesive composition.

In the invention of claim 4 of the present application, forming an adhesive layer means, for example, laminating an adhesive layer on at least one surface of a base material such as a tape, or providing an adhesive layer on the surface of an adherend. Say.

The paper product on which the adhesive layer of the hot melt adhesive composition is formed is, for example, a book bound by using the hot melt adhesive composition, a paper bag on which the adhesive layer is formed, or a bag-making product. The used paper bag, the manufactured box, the manufactured paper tube, the heat-sensitive tape or label provided with the adhesive layer, the rewetting tape or the label product are used.

The production of these paper products is carried out by a conventional method, and the coating method is, for example, roll, die,
Generally, a hot-melt coater such as a nozzle or a lip is used.

[0030]

The hot melt adhesive composition according to the present invention comprises:
PVA resin having an average degree of polymerization of 50 to 600 and saponification degree of 20 to 80 mol%, a tackifying resin having an acid value of 50 or more, and a terpene phenol tackifying resin having an average number of hydroxyl groups of 1.5 or more per molecule. , Or a ketone-based tackifying resin, the compatibility with the PVA-based resin is excellent, and the resulting adhesive composition has little phase separation and structural viscosity at the time of melting and impairs melt stability and coatability. Without this, a book, a paper bag, a paper tube, a heat-sensitive tape or label, a rewetting tape, a label product, or the like can be easily manufactured.

[0031]

EXAMPLES Examples of the present invention will be described below. Examples 1 to 32, Comparative Examples 1 to 16 Each component was blended at the blending composition and blending ratio as shown in Tables 1 to 5, and the blended mixture was melt-mixed at 170 ° C. to form a uniform mixed composition. None, Examples 1-3, respectively
2. Hot melt adhesive compositions of Comparative Examples 1 to 16 were obtained. Performance tests were performed on the hot melt adhesive compositions obtained in Examples 1 to 32 and Comparative Examples 1 to 16 by the following method. The results are also shown in Tables 1 to 5.

Performance Test Method Each hot melt adhesive composition was placed in a compatible 200 ml transparent bottle, which was melted at a temperature of 180 ° C., and the appearance of the melt was visually observed. Thus, the compatibility was examined. In addition,
The evaluation criteria are as follows. ○: transparent, ×: opaque.

Adhesiveness 1 Each hot melt adhesive composition was melted at 180 ° C., and the hot melt adhesive melted with a glass rod was applied to a 50 mm wide K liner corrugated board in a linear form of about 3 mm, and immediately thereafter another A K-liner cardboard with a width of 50 mm was attached. After left at room temperature for 1 day, it is peeled off by hand and the adhesion state is observed. In addition,
The evaluation criteria are as follows. ○ Paper breakage ratio: 50% or more, △: Paper breakage ratio 25 to less than 50%,
X: Paper breakage rate is less than 25%.

Adhesiveness 2 On 200 μm thick art paper, each hot melt adhesive melted at a temperature of 180 ° C. is applied to a thickness of 200 μm, and immediately thereafter, fine paper of size 50 mm × 50 mm is set in a book shape. One end of the above-mentioned product was adhered to the adhesive layer to prepare a mini book. Using this mini book as a test piece, it was aged at a temperature of 20 ° C for 7 days, and at the same temperature, two paper sheets of 100 were used.
The strength when pulled at a speed of mm / min was measured.

Adhesiveness 3 Each hot melt adhesive composition was melted at 160 ° C., and a kraft paper (100 g basis weight was used) using a die coater (Acumeter LH-1 manufactured by US Accumer Laboratory Co., Ltd.). / M ² ) and the thickness of the adhesive layer is 3
A tape was prepared by coating so as to have a thickness of 0 μm. This tape is heat-sealed at a temperature of 100 ° C and a pressure of 2 kg / c.
After adhering on a K-liner cardboard under the condition of m ² for 1 minute, it is left at room temperature for 1 day and then peeled by hand to observe the adhesion state. The evaluation criteria are as follows. ◯: Paper breakage rate of 50% or more, Δ: Paper breakage rate of 25 to less than 50%,
X: Paper breakage rate is less than 25%.

High-temperature and high-humidity resistance K liner corrugated board having a width of 50 mm is coated with each hot-melt adhesive in a line shape of about 3 mm, and immediately after that, K of the same width is applied.
A liner ball was overlaid and adhered to the above cardboard. The obtained adhesive cardboard was used as a test piece, and after curing for 7 days at a temperature of 40 ° C. and a humidity of 80% RH, a static load of 200 g was applied to one of the cardboards of the test piece under the same conditions. The time until it peeled off from the cardboard and fell was measured. Thus, the quality of the high temperature and high humidity resistance of the adhesive was examined.

A small piece of 20 mm × 20 mm × 1 mm was prepared from a water-soluble adhesive, and this piece was used as a test piece and immersed in warm water at a temperature of 30 ° C.
The mixture was stirred for 60 minutes and the dissolved state of the adhesive was visually observed. Thus, the water solubility of the adhesive was examined. In addition,
The evaluation criteria are as follows. ◯: Fine dispersion, ×: Adhesive remains in a lump.

Each component in the composition column in Tables 1 to 5 is as follows. PVA1 : average degree of polymerization 150, degree of saponification 50 mol%. PVA2 : average degree of polymerization 250, degree of saponification 60 mol%. PVA3 : vinyl versatate modified PVA, modification amount 4
% By weight, average degree of polymerization 100, degree of saponification 55 mol%. PVA4 : average degree of polymerization 150, degree of saponification 10 mol%. PVA5 : average degree of polymerization 700, degree of saponification 65 mol%. PVA6 : average degree of polymerization 150, degree of saponification 95 mol%.

Rosin-modified maleic acid resin 1 : manufactured by Arakawa Chemical Co., Ltd .: trade name "Marquide No. 32", acid value about 130. Rosin-modified maleic acid resin 2 : manufactured by Harima Chemicals: trade name "Harimac FX25", acid value: about 160. Rosin-modified maleic acid resin 3 : manufactured by Arakawa Chemical Co., Ltd .: trade name "Marquide No. 1", acid value about 20. Rosin-modified maleic acid resin 4 : manufactured by Harima Chemicals: trade name "Harimac 145P", acid value: about 25.

Rosin-modified special synthetic resin : manufactured by Harima Kasei Co., Ltd .: trade name "Harimac 2723", acid value: about 170.

Rosin-modified phenol resin 1 : manufactured by Harima Kasei: trade name "Hariphenol P1", acid value: about 150. Rosin-modified phenolic resin 2 : manufactured by Harima Chemicals: trade name "Hariphenol PS230", acid value about 25.

Petroleum resin : manufactured by Mitsui Petrochemical Co., Ltd .: trade name "FTR6100", acid value 0.1 or less. Disproportionated rosin ester resin : manufactured by Arakawa Chemical Co., Ltd .: trade name "Super Ester A75", acid value 10 or less. Modified ethylene-vinyl acetate copolymer : manufactured by Takeda Pharmaceutical Co., Ltd .: trade name "Dumilan D219". Ethylene-vinyl acetate copolymer : Mitsui-DuPont Polychemical Co., Ltd .: trade name "Eva Flex 210". Polyethylene glycol : molecular weight 600.

Terpene Phenolic Resin 1 : Yasuhara Chemical Co .: Trade Name "Mighty Ace G125", 1
1.7 hydroxyl groups per molecule, softening point about 125 ° C. Terpene phenolic resin 2 : Yasuhara Chemical Co., Ltd .:
Product name "Mighty Ace G150", 1.7 hydroxyl groups per molecule, softening point about 150 ° C. Terpene Phenolic Resin 3 : Yasuhara Chemical Co .:
Product name "YS Polystar T-115", 1.2 hydroxyl groups per molecule, softening point of about 115 ° C. Terpene Phenolic Resin 4 : Yasuhara Chemical Co .:
Product name "YS Polystar T-145", 1.2 hydroxyl groups per molecule, softening point of about 145 ° C.

Ketone-based resin 1 : manufactured by Hitachi Chemical Co., Ltd .: trade name "Hirac 110H". Ketone resin 2 : Made by Hitachi Chemical: Product name "Hirac 9
01 ”.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

[0048]

[Table 4]

[0049]

[Table 5]

As can be seen from Tables 1 to 6, the hot melt adhesive compositions of the examples are superior in compatibility and the like as those of the comparative examples and sufficiently satisfy the performance as the hot melt adhesive composition. I understand.

[0051]

The hot melt adhesive composition of the present invention comprises:
Since each has the above-mentioned constitution, it is excellent in compatibility with PVA-based resin, and the resulting adhesive composition has little phase separation at the time of melting and structural viscosity and impairs melt stability and coatability. Therefore, it is possible to easily manufacture a book, a paper bag, a paper tube, a heat-sensitive tape or label, a rewetting tape or a label product.

Since the paper product of the present invention has the above-mentioned constitution, it has an adhesive performance as a backing material for bookbinding, a seal or box for corrugated cardboard or a carton, a heat-sensitive tape or label, a rewetting tape or a label product. Is excellent, and when these are recovered as used paper after use, no troubles due to the adhesive occur in the used paper recycling process, and no adhesive piece remains in the recycled paper product,
Therefore, the problem that the regenerated product has spots due to heating due to the residual hot melt adhesive does not occur.

Claims (4)

[Claims] 1. An average degree of polymerization of 50 to 600 and a degree of saponification of 20.
~ 80 mol% polyvinyl alcohol resin, acid value 5
A hot-melt adhesive composition, characterized in that a main component is one containing 0 or more tackifying resin. 2. An average degree of polymerization of 50 to 600 and a degree of saponification of 20.
A hot-melt adhesive composition characterized in that a main component is a mixture of ˜80 mol% polyvinyl alcohol resin with a terpene phenolic tackifying resin having an average number of hydroxyl groups per molecule of 1.5 or more. object. 3. An average degree of polymerization of 50 to 600 and a degree of saponification of 20.
A hot-melt adhesive composition comprising a mixture of ˜80 mol% polyvinyl alcohol resin and a ketone tackifying resin as a main component. 4. A paper product having an adhesive layer formed from the hot melt adhesive composition according to claim 1, claim 2 or claim 3.