JPH06228527A - Hot-melt adhesive composition - Google Patents

Abstract

PURPOSE:To provide a composition which has a suitable melt viscosity and therefore can develop excellent adhesiveness while it retains good workability. CONSTITUTION:The composition comprises 100 pts.wt. base polymer, 10-300 pts.wt. tackifier and 1-100 pts.wt. modified polyolefin of an intrinsic viscosity of 0.01-0.6dl/g, prepared by grafting 1-60wt.% monomer represented by the formula (wherein R<1> is 1-5C alkyl; R<2>, R<3> and R<4> which may be the same or different from each other are each hydrogen or methyl; and n is 0 or a positive integer) onto a polyolefin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot melt adhesive composition, and more particularly, to a hot melt adhesive composition having an appropriate melt viscosity and capable of exhibiting excellent adhesive strength while maintaining good workability. It relates to an adhesive composition.

[0002]

2. Description of the Related Art As an adhesive agent which is applied to a label, craft tape, cloth tape, etc., to exert an adhesive effect by heating,
Well-known hot melt adhesives are based on polymers such as polyolefins, polyamides, polyesters, vinyl acetate copolymers, cellulose derivatives, polymethylmethacrylate, polyvinyl ethers and polyurethanes, to which tackifying resins are added. . Usually, this kind of hot melt adhesive contains a wax composed of a low molecular weight polyolefin in order to lower the melt viscosity to obtain good workability and to prevent the adhesive from causing a stringing phenomenon during the work. ing.

[0003]

However, many waxes, including the sazol wax often used for this purpose, have the problem that the adhesive strength is reduced when blended in a hot melt adhesive. However, in recent years, there has been a demand for hot-melt adhesives having a higher adhesive strength than conventional ones.

Therefore, an object of the present invention is to provide a hot melt adhesive composition having an appropriate melt viscosity and capable of exhibiting excellent adhesive strength while maintaining good workability.

[0005]

In order to solve the above-mentioned problems, the present invention comprises (A) 100 parts by weight of base polymer,
(B) 10 to 300 parts by weight of a tackifier, and (C) a polyolefin, with the general formula (I):

[Chemical 2] [In the formula, R ¹ is an alkyl group having 1 to 5 carbon atoms,
R ² , R ³ and R ⁴ may be the same or different,
A hydrogen atom or a methyl group, and n is 0 or a positive integer] 1 to 60% by weight of a monomer represented by graft copolymerization, and an intrinsic viscosity of 0.01 to 0.6 dl / g. The present invention provides a hot melt adhesive composition containing 1 to 100 parts by weight of a modified polyolefin.

The hot melt adhesive composition of the present invention (hereinafter referred to as "the composition of the present invention") will be described in detail below.

The base polymer (A) used in the composition of the present invention may be a polymer usually used in hot melt adhesives and is not particularly limited, and examples thereof include the following. 1) polyethylene 2) ethylene-vinyl acetate copolymer (EVA) 3) modified EVA such as saponified EVA and graft modified EVA
Polymer 4) Ethylene / (meth) ethyl acrylate (EEA)
An ethylene / (meth) acrylate copolymer such as 5) An ionomer resin obtained by partially neutralizing an ethylene / (meth) acrylic acid copolymer. Specific examples thereof include those marketed by Mitsui DuPont Polychemical Co., Ltd. under the trade name of Himilan. 6) Ethylene / propylene copolymer, ethylene / propylene / (meth) acrylic acid terpolymer 7) Polyamide: A reaction product of a dibasic acid and a diamine, for example, a fatty acid such as soybean oil, tung oil, or tall oil.
Reaction products of dimer acid, which is a monomer, and alkyldiamines such as ethylenediamine and diethylenetriamine, and nylons such as nylon 12, as specific examples of these, such as diamide (Daicel Chemical Industry), platinone (Toagosei Chemical Industry), Examples include those marketed under the trade name of Amilan (Toray) and the like. 8) Polyester: For example, those commercially available under the trade names of ester resins 200 and 300 (Toyobo), Vita 1200 and 300 (Goodyear) can be mentioned. 9) Propylene-based polymer: atactic polypropylene and the like can be mentioned. 10) Copolymer composed of vinyl aromatic compound and conjugated diene compound, and hydrogenated product thereof: specifically, styrene
Butadiene random copolymer, styrene / isoprene random copolymer, butadiene / polystyrene block copolymer, polystyrene / polyisoprene block copolymer, polystyrene / polyisoprene / polystyrene triblock copolymer, polystyrene / polybutadiene / polystyrene triblock Examples thereof include copolymers, poly (α-methylstyrene) / polybutadiene / poly (α-methylstyrene) triblock copolymers, and hydrogenated products thereof.

These polymers can be obtained as commercial products, and hydrogenated products are also commercially available. For example, Califlex TR-1101, TR-1107, TR-
4113 (manufactured by Shell Chemical Co., Ltd.), Kraton G-650
0, G-6521, G-1650, G-1652, G-
Examples thereof include those marketed under the trade names of 1657 (manufactured by Shell Chemical Co., Ltd.), sorbrene, hydrogenated sorbrene (manufactured by Philips). 11) Other polymers: vinyl acetate copolymer-based polymer, vinyl acetate-crotonic acid copolymer-based polymer, vinyl acetate-phthalic anhydride copolymer-based polymer, vinyl acetate-vinylpyrrolidone copolymer-based polymer, cellulose derivative-based polymer, polymethyl Methacrylate type polymers, polyvinyl ether type polymers, polyurethane type polymers, thermosetting resin type polymers, syndiotactic polypropylene, ethylene-propylene type polymers and the like can be mentioned.

In the composition of the present invention, these (A)
The base polymer may be used alone or in combination of two or more.

The tackifier, which is the component (B) of the composition of the present invention, is blended in order to adjust the viscosity of the (A) base polymer in the molten state and to improve the hot tack property and the wettability. is there. The (B) tackifier is not particularly limited as long as it is mixed with the (A) base polymer and improves the hot tack property and wettability of the (A) base polymer when heated. .

Specific examples of the tackifier (B) include aliphatic hydrogenated tackifiers, rosins, modified rosins or their esterified products, aliphatic petroleum resins, alicyclic petroleum resins, and aromatic petroleum oils. Examples of suitable tackifiers include resins, copolymerized petroleum resins of aliphatic and aromatic components, low molecular weight styrene resins, isoprene resins, alkylphenol resins, terpene resins, coumarone / indene resins.

In the composition of the present invention, these (B)
The tackifiers may be used alone or in combination of two or more.

These (B) tackifiers can be appropriately selected according to the (A) base polymer used. For example, when an ethylene-vinyl acetate copolymer (EVA) is used as the (A) base polymer,
It is preferable to use alicyclic petroleum resin and (modified) rosin.

The modified polyolefin which is the component (C) of the composition of the present invention is obtained by graft-copolymerizing the monomer represented by the general formula (I) with polyolefin.

The polyolefin which is the main material of the modified polyolefin (C) is a homopolymer consisting of one type of α-olefin having 2 to 12 carbon atoms or a copolymer consisting of two or more types. Examples of the α-olefin having 2 to 12 carbon atoms include ethylene, propylene, butene-1, pentene-1,2-methylbutene-1,3-methylbutene-1, hexene-1, -methylpentene-1,4-methylpentene-1,3. , 3-dimethylbutene-1, heptene-1, methylhexene-1, dimethylpentene-1, trimethylbutene-1, ethylpentene-1, octene-1, methylpentene-1, dimethylhexene-1, trimethylpentene-1, ethylhexene-1, methylethyl Pentene-1, diethylbutene-1, propylpentene-1, decene-1, methylnonene-1, dimethyloctene-1, trimethylheptene-1, ethyloctene-1, methylethylheptene-1, diethylhexene-1, dodecene-1, hexadodecene 1, and the like.

As the polyolefin, a low molecular weight polyolefin having an intrinsic viscosity [η] of 0.01 to 0.8 dl / g is preferable.

The production of these low molecular weight polyolefins can be carried out according to known methods. For example, a high pressure radical polymerization method, a production method by a medium / low pressure polymerization method performed in the presence of various transition metal catalysts such as a Ziegler catalyst,
Alternatively, there can be mentioned a thermal decomposition method in which a high molecular weight polyolefin is produced by a polymerization method and then the molecular weight of the high molecular weight polyolefin is reduced by thermal degradation or radical degradation using a peroxide.

In the present invention, the monomer to be graft-copolymerized with the polyolefin is represented by the general formula (I). In this general formula (I), R ¹ is an alkyl group having 1 to 5 carbon atoms, for example, a methyl group, an ethyl group, a propyl group, a butyl group, an i-butyl group, a t-butyl group, a pentyl group, i -Pentyl group, neo-pentyl group, t-pentyl group and the like can be mentioned. Of these, a methyl group and an ethyl group are preferable. Also,
R ² , R ³ and R ⁴ may be the same or different,
It is a hydrogen atom or a methyl group, and n is 0 or a positive integer.

Specific examples of the monomer represented by the general formula (I) include vinyl acetate and vinyl propionate. Among these, vinyl acetate is particularly preferable because it has high reactivity, is easily available, and is advantageous in terms of cost.

In the present invention, the grafting amount of the (C) modified polyolefin has good compatibility with polar polymers such as ethylene-vinyl acetate copolymer (EVA), and also improves the stringing prevention property. From the viewpoint of obtaining a hot melt adhesive having good workability, 1 to 60% by weight is preferable, and 5 to 40% by weight is particularly preferable.

Further, the (C) modified polyolefin is excellent in that the obtained hot-melt adhesive composition has a melt viscosity exhibiting good workability and the hot-melt adhesive composition has an appropriate cohesive force. The intrinsic viscosity is from 0.01 to 0.6 dl / g, preferably from 0.05 to 0.5 dl / g, from the viewpoint of obtaining adhesive strength.

The modified polyolefin can be produced, for example, according to a known method. For example, the polyolefin, the monomer represented by the general formula (I) and the peroxide are put in a mixer such as a Henschel mixer or a blender, mixed, and the resulting mixture is heated and melted by an extruder or the like. In order to carry out the graft copolymerization reaction at a temperature above the decomposition temperature of the peroxide and above the melting point of the polyolefin, put the polyolefin in a reactor and heat at a temperature above the melting point and above the decomposition temperature of the peroxide used. Method of melting and successively dropping the monomer and peroxide to carry out a graft copolymerization reaction: polyolefin is impregnated with a monomer and, if necessary, a peroxide, and heated or irradiated with actinic rays. And a method of carrying out a graft copolymerization reaction. In these methods, the peroxide is not always necessary, and the graft copolymerization reaction can be performed even in the absence of the peroxide.

If necessary, the monomer and peroxide represented by the general formula (I) are successively added dropwise to a solution obtained by heating and dissolving a polyolefin in an organic solvent to carry out a graft copolymerization reaction. Or a method of carrying out a graft copolymerization reaction by successively dripping the monomer represented by the general formula (I) and a peroxide into an aqueous suspension obtained by dispersing a polyolefin in water. Can also be used.

In the composition of the present invention, the modified polyolefin (C) may be used alone or in combination of two or more.

In the composition of the present invention, the blending ratio of the (A) base polymer, (B) tackifier and (C) modified polyolefin is such that (B) tackiness agent is added to 100 parts by weight of (A) base polymer. It is a ratio of 10 to 300 parts by weight of the imparting agent and 1 to 100 parts by weight of the (C) modified polyolefin, and the cohesive force of the (A) base polymer, the adhesive force of the (B) tackifier and the function of the (C) modified polyolefin. The (A) base polymer 100 has a good balance and is capable of exhibiting excellent adhesive strength while maintaining good workability because it has an appropriate melt viscosity.
The ratio of 50 to 200 parts by weight of the tackifier (B) and 20 to 80 parts by weight of the modified polyolefin (C) is preferable with respect to parts by weight.

When the composition of the present invention is blended with an unmodified polyolefin, for example, Sazol wax (H-1 manufactured by Sazol Co.) which is blended in a usual hot melt adhesive, the melt viscosity is lowered, Workability can be further improved.

The composition of the present invention may contain various additives other than the above-mentioned (A) base polymer, (B) tackifier and (C) modified polyolefin, as required, within a range not impairing the object of the present invention. Agents such as softeners, stabilizers,
Fillers, antioxidants and the like can be added.

The composition of the present invention is prepared by adding the above-mentioned (A) base polymer, (B) tackifier and (C) modified polyolefin and, if necessary, the above-mentioned various components.
It is supplied to a mixer such as Brabender at a predetermined mixing ratio, heated and melt-mixed, and then it is formed into a desired shape, for example, granular,
It can be performed by molding into flakes, rods, or the like.

The composition of the present invention is prepared by heating and melting this composition,
The hot melt adhesive layer can be formed by applying it to an object to be coated such as cloth, kraft paper, aluminum foil, polyester film, etc. by a usual method, and then used.

[0030]

EXAMPLES Examples will be described below, but the present invention is not limited to the examples.

Example 1 <Synthesis of Modified Polyolefin> Unmodified Polyethylene (Mitsui Petrochemical Industry Co., Ltd., Mitsui High Wax 200P:
600 g of an intrinsic viscosity of 0.13 dl / g was charged in a 1.5 l glass reactor and heated to 160 ° C. to melt it. Next, while maintaining the temperature, 267 g of vinyl acetate and 14.8 g of di-tert-butyl peroxide were added dropwise over 3 hours. After completion of the dropping, the reaction was continued for another 1 hour, and in the molten state, deaeration treatment was performed in a vacuum of 10 mmHg for 1 hour to remove volatile components, followed by cooling to obtain a modified wax. The intrinsic viscosity of the obtained modified wax is 0.
The amount of grafted vinyl acetate was 13 dl / g and 28% by weight. (This modified wax is hereinafter referred to as "W-1")

Ethylene-vinyl acetate copolymer (EVA #
220: Mitsui DuPont Polychemical Co., Ltd.) 40 g, aliphatic petroleum resin (HILETS T-500X: Mitsui Petrochemical Industry Co., Ltd.) 40 g, and W-12 obtained above.
0 g was melt mixed at 180 ° C. to prepare a hot melt adhesive composition. The melt viscosity of this hot melt adhesive composition is 6800 cp at 160 ° C. and 3900 c at 180 ° C.
It was p.

This hot melt adhesive composition was applied on one side of an aluminum foil (thickness: 50 μm) to a thickness of 15 μm. Next, the coated surfaces are stuck together, and the upper bar 170
The sheet was heat-sealed under the conditions of a temperature of 70 ° C., a lower bar temperature of 70 ° C. and a pressure of 1 kg / cm ^{2 for} pressure bonding for 2 seconds to prepare an adhesive piece in which an aluminum foil was attached via a hot melt adhesive layer. This adhesive piece was cut into a width of 25 mm to prepare a sample, and a T-type peel test was performed at a tensile speed of 300 mm / min at a measurement temperature of 0 to 80 ° C. to measure the adhesive strength. The results are shown in Tables 1 to 3.

(Examples 2 and 3) Instead of W-1, W-
A hot melt adhesive composition having a compounding ratio shown in Table 1 was prepared in the same manner as in Example 1 except that a mixture prepared by mixing 1 / sazol wax was used. And the adhesive strength was measured. The results are shown in Table 1
3 shows.

(Comparative Example 1) A hot melt adhesive composition was prepared in the same manner as in Example 1 except that only sazol wax was used in place of W-1, and further the same as in Example 1. Melt viscosity and adhesive strength were measured. The results are shown in Tables 1 to 3.

(Comparative Example 2) Instead of W-1, Example 1 was used.
The unmodified polyethylene used in 1. was mixed to prepare a hot melt adhesive composition, and the melt viscosity and the adhesive strength were measured in the same manner as in Example 1. The results are shown in Tables 1 to 3.

[0037]

[0038]

[0039]

[0040]

The hot melt composition of the present invention has an appropriate melt viscosity, so that good workability is maintained,
It can exhibit excellent adhesive strength.

Claims (1)

[Claims] 1. A base polymer (A) 100 parts by weight,
(B) 10 to 300 parts by weight of a tackifier, and (C) a polyolefin, with the general formula (I): [In the formula, R ¹ is an alkyl group having 1 to 5 carbon atoms,
R ² , R ³ and R ⁴ may be the same or different,
A hydrogen atom or a methyl group, and n is 0 or a positive integer] 1 to 60% by weight of a monomer represented by graft copolymerization, and an intrinsic viscosity of 0.01 to 0.6 dl / g. A hot melt adhesive composition comprising 1 to 100 parts by weight of a modified polyolefin.