JPH06228529A - 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.% styrene monomer 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 or the like 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 provides 100 parts by weight of (A) base polymer,
(B) 10 to 300 parts by weight of a tackifier, and (C) an intrinsic viscosity of 0.01 to 0.6 dl / g obtained by graft-copolymerizing a styrene-based monomer with 1 to 60% by weight of a polyolefin.
To provide a hot melt adhesive composition containing 1 to 100 parts by weight of the 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 (SIS), polystyrene / polybutadiene / Polystyrene triblock copolymer (SB
S), poly (α-methylstyrene) / polybutadiene /
Poly (α-methylstyrene) triblock copolymer and hydrogenated products thereof, for example, polystyrene / polybutadiene / polystyrene triblock copolymer (SBS)
(SEBS), a hydrogenated product of polystyrene / polyisoprene / polystyrene triblock copolymer (SIS) (SEPS), and the like.

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. Further, among these (A) base polymers, a copolymer comprising a vinyl aromatic compound such as SBS, SEBS, SIS and SEPS and a conjugated diene or a hydrogenated product thereof is compatible with the (C) modified polyolefin. Is favorable, and a hot melt adhesive composition having excellent adhesive strength can be obtained, which is advantageous. Also, (A)
When the base polymer is an oxidized one, it has an excellent compatibility with the (C) modified polyolefin and is advantageous in that a hot melt adhesive composition having excellent adhesive strength can be obtained.

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 a styrene-based monomer with the polyolefin.

The polyolefin, which is the main material of the modified polyolefin (C), is a homopolymer of one type of α-olefin having 2 to 12 carbon atoms or a copolymer of two or more types thereof. 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, methylethylpentene-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.

Further, in the present invention, since the hot melt adhesive composition having an appropriate melt viscosity and exhibiting good workability can be obtained, the polyolefin has an intrinsic viscosity [η] of 0. 01-0.8 dl / g
Low molecular weight polyolefins in the range of are preferred.

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 composition of the present invention, (C) the polyolefin as the main material of the modified polyolefin,
Oxidized polyolefin obtained by oxidizing the above-mentioned polyolefin with an oxygen-containing gas may be used. The oxidized polyolefin preferably has an acid value of 0.1 to 100 KOHmg / g in order to improve workability and compatibility with polar polymers such as ethylene / vinyl acetate copolymer. Furthermore, the (C) modified polyolefin may be one obtained by modifying the polyolefin by graft copolymerization and then oxidizing it.

As a method for producing such an oxidized polyolefin, there can be mentioned a method in which a molten polyolefin is brought into contact with an oxygen-containing gas to cause a reaction.
(Japanese Patent Publication No. 48-37991) For example, it can be carried out by a method such as heating the polyolefin to a temperature above the softening point to melt it in an autoclave and bubbling an oxygen-containing gas while stirring.

Examples of the styrene-based monomer graft-copolymerized with these polyolefins include styrene and α
-Methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, 2,4-dimethylstyrene, 2,5-dimethylstyrene, o-chlorostyrene,
Examples thereof include p-chlorostyrene and m-chlorostyrene. These may be used alone or in combination of two or more.

In the present invention, the graft amount of the styrene-based monomer in the (C) modified polyolefin is compatible with the base polymer such as hydrogenated product (SEBS) of polystyrene / polybutadiene / polystyrene triblock copolymer. Is from 1 to 60% by weight, and particularly from 5 to 40% by weight, in that the hot melt adhesive composition having good workability, improved threading prevention property and good workability can be obtained. Is preferred.

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 according to a known method described in, for example, JP-A-58-65731. For example, a Henschel mixer,
In a mixer such as a blender, the polyolefin, the styrene-based monomer and the peroxide are put and mixed, and the resulting mixture is placed in a heating and melting device such as an extruder, and the temperature is not lower than the decomposition temperature of the peroxide and the polyolefin is Method for carrying out a graft copolymerization reaction at a temperature above the melting point of: the polyolefin is placed in a reactor and heated and melted at a temperature above the melting point and above the decomposition temperature of the peroxide used, and the styrene monomer and peroxide A method of carrying out a graft copolymerization reaction by sequentially dropping styrene: a styrene monomer and, if necessary, a peroxide impregnated with a polyolefin, and carrying out a graft copolymerization reaction by heating or irradiating with actinic rays. The method of making it etc. can be mentioned. 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 desired, the styrene-based monomer and the peroxide are successively added dropwise to a solution obtained by heating and dissolving the polyolefin in an organic solvent to carry out a graft copolymerization reaction, or a polyolefin. It is also possible to use a method in which the styrene-based monomer and the peroxide are successively added dropwise to an aqueous suspension obtained by dispersing the above in water to carry out a graft copolymerization reaction.

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 mixing ratio of the above-mentioned (A) base polymer, (B) tackifier and (C) modified polyolefin is (A) base polymer 100.
The proportion of 10 to 300 parts by weight of the (B) tackifier and 1 to 100 parts by weight of the (C) modified polyolefin with respect to parts by weight, where (A) the cohesive force of the base polymer and (B) the tackiness of the tackifier. The force and the function of the modified polyolefin (C) are exerted in a well-balanced manner, and since it has an appropriate melt viscosity, it is possible to develop an excellent adhesive force while maintaining good workability. Polymer 10
A 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 0 parts by weight.

Further, when an unmodified polyolefin, for example, Sazol wax (H-1: manufactured by Sazol Co.), which is added to an ordinary hot melt adhesive, is added to the composition of the present invention, the melt viscosity is lowered, Workability can be further improved.

The composition of the present invention may contain various components other than the above-mentioned (A) base polymer, (B) tackifier and (C) modified polyolefin, if necessary, 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.

[0031]

EXAMPLES Examples and comparative examples of the present invention will be given below.
The present invention will be described in more detail, but the present invention is not limited to these examples.

Example 1 <Synthesis of Modified Polyolefin> Unmodified Polyethylene (Mitsui Petrochemical Industry Co., Ltd., Mitsui High Wax 220M)
P: Intrinsic viscosity 0.13 dl / g, acid value: 1 KOHmg /
g) 600 g was charged into a 1.5 l glass reactor,
It was heated to 160 ° C. and melted. Next, while maintaining the temperature, 267 g of styrene and 14.8 g of di-tert-butyl peroxide were added dropwise over 3 hours. After the dropping is completed,
After reacting for another 1 hour, 10mm in the molten state
Degassing was carried out in Hg vacuum for 1 hour to remove volatile matter, and then cooling was performed to obtain a modified wax. The obtained modified wax had an intrinsic viscosity of 0.13 dl / g and a styrene graft amount of 28% by weight.
Hereinafter referred to as "W-1").

SEBS (G-1657: Shell Chemistry) 4
0 g, aliphatic petroleum resin (HILETS T-500X: Mitsui Petrochemical Industry Co., Ltd.) 40 g, and W-1 20 g obtained above were melt mixed at 180 ° C. to prepare a hot melt adhesive composition. . At this time, the melt viscosity of the hot melt adhesive composition was 68000 cp at 180 ° C. and 2
It was 35,000 cp at 00 ° C.

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 pasted together, and in a heat sealing machine, the upper bar temperature is 170 ° C. and the lower bar temperature is 70 ° C.
Heat-sealing was performed under the conditions of ° C and a pressure of 1 kg / cm ² for 2 seconds to prepare an adhesive piece in which an aluminum foil was bonded via a hot-melt adhesive layer. This adhesive piece is cut into a sample having a width of 25 mm to obtain a sample, and the tensile speed is 3 at a measurement temperature of 0 to 80 ° C.
A T-type peel test was performed at 00 mm / min to measure the adhesive strength. The results are shown in Tables 1 to 3.

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

(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.

[0038]

[0039]

[0040]

[0041]

The hot melt adhesive composition of the present invention comprises:
Since it has an appropriate melt viscosity, it can exhibit excellent adhesive strength while maintaining good workability.

Claims (1)

[Claims] 1. A base polymer of 100 parts by weight,
(B) 10 to 300 parts by weight of a tackifier, and (C) an intrinsic viscosity of 0.01 to 0.6 dl / g obtained by graft-copolymerizing a styrene-based monomer with 1 to 60% by weight of a polyolefin.
A hot melt adhesive composition containing 1 to 100 parts by weight of the modified polyolefin.