JP2001114968A - Composition for high-frequency welding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for high-frequency welding which has such characteristics as to generate heat by a high frequency and which, when used for forming a layer of it or a layer of a blend containing it on at least a part of the surface of a polyolefin substrate, makes the substrate high-frequency- weldable to various members in a short time. SOLUTION: This composition comprises (A) a homopolymer of (a) a polymerizable monomer having a tertiary carbon atom and a double bond or (B) a copolymer of monomer (a) and another free-radically polymerizable compound, (C) a thermoplastic hydrogenated styrenic elastomer, and (D) a hydrogenated petroleum resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency fusing composition having the property of generating heat by high frequency and capable of fusing a polyolefin resin or the like.

[0002]

2. Description of the Related Art In recent years, as environmental problems have risen, polyolefin resins have attracted attention as non-polyvinyl chloride materials.
In particular, it is used in various fields such as food packaging, agriculture, medical care, industrial materials, stationery, and miscellaneous goods.

However, unlike poly (vinyl chloride), polyolefin resin does not have a polar group in its molecule, so that it has been difficult to perform fusion using high frequency or microwave. Thus, for example, JP-A-6-182876 discloses a method of imparting high-frequency fusing property to a polyolefin resin by blending and / or applying a radio wave absorber such as ferrite to the polyolefin resin. Further, Japanese Patent Application Laid-Open No. 9-263657 discloses that a thermoplastic resin composition comprising a compound having a hydroxyl group is used for high frequency welding.

[0004] However, the method of blending and / or coating ferrite has a problem that the high-frequency fusion property is insufficient and that the molded product is colored. In addition, when a thermoplastic resin composition having a hydroxyl group is used, the thermoplastic resin composition generates heat by high frequency, but the fusion is insufficient due to a difference in polarity with the polyolefin resin. There was a problem.

Japanese Patent Application Laid-Open No. Hei 10-147675 discloses a method of using an olefin thermoplastic elastomer for high frequency sealing, which is obtained by mixing a polypropylene resin and a hydrogenated styrene elastomer resin. However, this olefin-based thermoplastic elastomer for high-frequency sealing has a problem that heat generation by high frequency is small, and it takes time for fusion.

[0006]

SUMMARY OF THE INVENTION In view of the above, the present invention has the property of generating heat by high frequency, and by forming a layer of these compositions on the entire surface or a part of the surface of a polyolefin-based substrate. It is another object of the present invention to provide a high-frequency welding composition which enables high-frequency welding of a polyolefin-based member to various members in a short time.

[0007]

According to the present invention, there is provided a homopolymer A of a polymerizable monomer (a) having a tertiary carbon and an unsaturated double bond, or the polymerizable monomer (a). And a hydrogenated styrene-based thermoplastic elastomer C, and a hydrogenated petroleum-based resin D. Hereinafter, the present invention will be described in detail.

The high-frequency welding composition of the present invention comprises a homopolymer A having a tertiary carbon and an unsaturated double bond, or the above-mentioned polymerizable monomer (a) and another radical polymerizable compound. Contains copolymer B.

The polymerizable monomer (a) having a tertiary carbon and an unsaturated double bond is not particularly limited, and examples thereof include tert-butyl (meth) acrylate and tert-butyl (meth) acrylate.
-Butylphenyl methacrylate, N-tert-butyl (meth) acrylamide, tert-butylaminoethyl methacrylate and the like. Of these, tert-butyl (meth) acrylate is preferred.

The other radically polymerizable compounds include:
There is no particular limitation as long as it is copolymerizable with the polymerizable monomer (a). For example, methyl (meth) acrylate,
Ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, sec
-Butyl (meth) acrylate, cyclohexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isononyl (meth) acrylate, lauryl (meth) acrylate, dimethylaminomethyl (Meth) acrylate compounds such as (meth) acrylate, dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, and diethylaminoethyl (meth) acrylate; aromatic vinyls such as α-methylstyrene, vinyltoluene, and styrene Compounds; Vinyl ether compounds such as methyl vinyl ether, ethyl vinyl ether and isobutyl vinyl ether; Nitrogen-containing vinyl compounds such as N-vinylpyrrolidone and acryloylmorpholine And vinyl acetate.
These other radically polymerizable compounds may be used alone or in combination of two or more.

The method for obtaining the homopolymer A or the copolymer B is not particularly limited, and examples thereof include known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. Among these, solution polymerization performed in a solvent such as toluene or ethyl acetate is preferred.

The high frequency welding composition contains a hydrogenated styrene-based thermoplastic elastomer C. The hydrogenated styrene-based thermoplastic elastomer C is not particularly limited, and examples thereof include styrene / ethylene / butylene / styrene block copolymer, styrene / ethylene / butylene block copolymer, and styrene / ethylene / propylene / styrene block copolymer. And a styrene / ethylene / propylene block copolymer. These hydrogenated styrene-based thermoplastic elastomers may be used alone or in combination of two or more.

The high frequency welding composition contains a hydrogenated petroleum resin D. The hydrogenated petroleum resin D is not particularly limited, and examples thereof include Alcon P-115 and Alcon P
-125, Archon P-series such as Archon P-140 (manufactured by Arakawa Chemical Co.); Archon M-115, Archon M-
135 and the like, and Escolets 5000 series (manufactured by Exxon Chemical Co., Ltd.) such as Escolets 5300, Escolets 5320 and Escolets 5380. Among these hydrogenated petroleum resins, alicyclic resins such as Alcon P-140 are preferred.

The above-mentioned high frequency welding composition may contain various known additives, for example, tackifier resins, plasticizers, softeners, fillers, stabilizers, and antioxidants, as long as the objects of the invention are not impaired. Agents, pigments and the like.

The high-frequency welding composition of the present invention can form a layer on the entire surface of a polyolefin-based substrate so that the polyolefin-based member can be high-frequency-fused with various members in a short time. .

Further, the high-frequency welding composition of the present invention comprises a layer of the high-frequency welding composition formed only on a portion of the polyolefin-based substrate to be fused, so that only a part of the polyolefin-based substrate is formed. Can also be used as a selective fusing agent capable of selectively fusing.

The method of forming the high-frequency welding composition layer on the surface of the polyolefin-based substrate is not particularly limited. For example, after preparing a solvent-based or aqueous solution containing the above-mentioned high-frequency welding composition and the like, Spraying the solution onto the substrate, or a method of applying and drying using a roll coater or the like,
A method of forming a surface layer composed of a high-frequency welding composition or the like integrated with the substrate by co-extrusion during the production of the substrate (co-extrusion method), a pressing heat lamination method of pressing with a hot plate, An extrusion laminating method for laminating is exemplified.

Therefore, the high frequency welding composition of the present invention comprises:
As adhesives and modifiers, for example, automotive vehicle parts,
It is useful in a wide range of fields, such as packaging materials for food and medical use, stationery, miscellaneous goods, electric parts such as home appliances, and various industrial materials.

[0019]

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

Production Examples 1-4 In a separable flask equipped with a stirrer, a cooler, a thermometer, and a nitrogen gas inlet, a monomer having a ratio shown in Table 1 below, 70 parts by weight of toluene and 30 parts by weight of ethyl acetate were prepared. The polymerization solvent was mixed to prepare a monomer mixed solution. The mixing ratio of each monomer is shown in Table 1 below.

Next, while replacing the inside of the separable flask with nitrogen gas, the monomer mixed solution was mixed and heated. Subsequently, after confirming that the liquid was refluxed in the cooling pipe, 1,1-di (t-hexylperoxy) -3,3,5-trimethylcyclohexane (manufactured by NOF Corporation, as a polymerization initiator, (Product name: PerhexaTMH) 0.01
The polymerization was started by adding parts by weight.

One hour after the start of the polymerization, 0.02 parts by weight of Perhexa TMH was added again. Also, 2 hours, 3 hours and 4 hours after the start of the polymerization,
(3,5,5-trimethylhexanoyl) peroxide (manufactured by NOF Corporation, trade name: Parloyl 355) 0.02
Parts by weight, 0.1 parts by weight, and 0.3 parts by weight were respectively charged. Polymerization was performed for 7 hours to obtain a polymer solution.

[0023]

[Table 1]

Examples 1 to 5 and Comparative Examples 1 to 4 Styrene / ethylene / butylene / styrene triblock copolymer (trade name: Tuftec H105, manufactured by Asahi Kasei Corporation)
2) and a hydrogenated petroleum-based resin (manufactured by Arakawa Chemical Co., Ltd., trade name: Alcon P-140), the solid content ratio of the polymer solution obtained in Production Examples 1 to 4 is as shown in Table 2 below. After dissolving and mixing as described above, the high-frequency fusion-bondable composition was obtained by removing volatile components in the solution.The obtained high-frequency fusion-bondable composition was evaluated using the following evaluation method. The results are shown in Tables 3 and 4.

[0025]

[Table 2]

[0026]Evaluation method  (A) Evaluation when a polyethylene film is used as a base material (1) Evaluation of adhesion to polyethylene First, a high-frequency fusible composition is thickened using a press machine.
Into a sheet of 300 μm in length, and then the resulting sheet
And a 100 μm thick polyethylene film
300μm thick integrated by pressing at 70 ℃
A sheet was prepared.

Next, after affixing a tape to the high-frequency-fusible composition side of the integrated sheet produced by the above method and peeling it off, the adhesiveness between the high-frequency-fusible composition layer and the polyethylene film is removed. Was evaluated. That is, when the tape is peeled off, it is difficult to peel off the tape, and the one that did not peel off at the interface between the high-frequency fusion bonding composition layer and the polyethylene film is regarded as “good”, and the interface between the high-frequency fusion bonding composition layer and the polyethylene film is The sample that easily peeled off was regarded as "defective".

(2) Measurement of high-frequency welding time Using a high-frequency welding machine (manufactured by Seidensha Electronics Co., Ltd.), two sheets of an integrated sheet similar to the integrated sheet produced in (1) above were subjected to high-frequency welding. 40.68 MHz superposed on the composition side
Was applied to produce a sample for peeling. In addition, this peeling sample, the application time of the high frequency,
A plurality of samples were manufactured while the length was increased, and the superposed surfaces of the respective samples were peeled off, and the high-frequency application time of the sample which was destroyed at the time of peeling was measured.

[0029]

[Table 3]

(B) Evaluation when a polypropylene film is used as a base material (1) Evaluation of adhesion to polypropylene The above (A) polyethylene film was used as a base material except that a polypropylene film was used instead of the polyethylene film. (2) Measurement of high-frequency fusion time Except for using a polypropylene film instead of a polyethylene film, the above (A) polyethylene film was used. The high-frequency fusion time was measured in the same manner as in (2) of the evaluation for a substrate.

[0031]

[Table 4]

[0032]

The high frequency welding composition of the present invention has the above-mentioned constitution, has the property of generating heat by high frequency, and forms a layer of these compositions on the entire surface of a polyolefin-based substrate or a part thereof. By doing so, the polyolefin-based member can be high-frequency fused to various members in a short time.

Claims (2)

[Claims] 1. A homopolymer A of a polymerizable monomer (a) having a tertiary carbon and an unsaturated double bond, or the polymerizable monomer (a) and another radical polymerizable compound. A high-frequency welding composition comprising a copolymer B of the formula (I), a hydrogenated styrene-based thermoplastic elastomer C, and a hydrogenated petroleum-based resin D. 2. The high frequency welding composition according to claim 1, wherein the polymerizable monomer (a) having a tertiary carbon and an unsaturated double bond is tert-butyl (meth) acrylate. object.