Hot Melt Composition

Abstract

To provide a hot-melt composition that has high strength and flexibility, wherein, even when being in contact with a low-molecular-weight oil component, the oil component is prevented from permeating into the hot-melt composition.SOLUTION: A hot-melt composition contains a styrenic thermoplastic elastomer (A), an ethylene-vinyl acetate copolymer (B), and Fischer-Tropsch wax (C).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a hot melt composition. [Background technology]

[0002] In general, hot melt compositions are solvent-free, environmentally friendly, can be cured in a short time, and are very easy to handle, which makes it possible to improve the working environment at manufacturing sites. Therefore, hot melt compositions are widely used in precision fields such as automobiles and electrical appliances, as well as in the construction field.

[0003] In the past, the applicant invented a hot melt composition characterized by containing hydrogenated paraffin process oil, high molecular weight styrene block copolymer, polyphenylene ether resin or modified polyphenylene ether resin, antioxidant, and amorphous polyalphaolefin (Patent Document 1). This hot melt composition had good adhesiveness and adhesion, inhibited deterioration due to heat, and was also excellent in dismantling properties. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-097360 A

[0005] Conventionally, hot melt adhesives are manufactured in a production facility, filled in a molten state through a discharge port into large containers such as drums, cooled at room temperature, and then sold to customers. When the customer uses the adhesive, the adhesive is reheated to a molten state and then applied to an adherend through a suction port.

[0006] However, in the case of hot melt adhesive filled in a drum, the cooling speed differs between the inner surface and the center of the drum, and the degree of thermal shrinkage differs, which may cause the hot melt adhesive to deform and generate voids. Also, when a customer reheats the hot melt adhesive and uses it, they need to visually check the hot melt adhesive at the deformed area beforehand and remove it to prevent air from being sucked in from the voids, which left room for improvement.

[0007] Therefore, a method is used in which each small piece of hot melt adhesive is packaged in a film made of a different hot melt composition with excellent durability and sold. This method has the advantage that the hot melt adhesive can be used by simply putting the packaged hot melt adhesive into a large heating device equipped with an application device. Therefore, various physical properties are required to be improved for the hot melt composition used to package the hot melt adhesive. Specifically, in addition to strength and flexibility when processed into a film, performance is required that prevents low molecular weight oil components contained in the hot melt adhesive from penetrating and leaking out to the outside. Summary of the Invention [Problem to be solved by the invention]

[0008] The problem to be solved by the present invention is to provide a hot melt composition which is excellent in strength and flexibility and which can inhibit the penetration of low molecular weight oil components even when the composition comes into contact with the oil components. [Means for solving the problem]

[0009] The present invention relates to a hot melt composition comprising a styrene-based thermoplastic elastomer (A), an ethylene-vinyl acetate copolymer (B), and a Fischer-Tropsch wax (C). Effect of the Invention

[0010] The hot melt composition of the present invention is excellent in strength and flexibility, and has the effect of being able to inhibit the penetration of low molecular weight oil components even when they come into contact with each other. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] <Styrene-based thermoplastic elastomer> In the present invention, a styrene-based thermoplastic elastomer (A) is used as a base polymer for the hot melt composition according to the present invention.

[0012] Examples of the component (A) include unhydrogenated block copolymers such as styrene-isoprene-styrene block copolymer (SIS) and styrene-butadiene-styrene block copolymer (SBS), and hydrogenated block copolymers such as styrene-butadiene / butylene-styrene block copolymer (SBBS), styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene-ethylene / propylene-styrene block copolymer (SEPS), and styrene-ethylene-ethylene / propylene-styrene block copolymer (SEEPS). Among these, it is preferable to use hydrogenated block copolymers.

[0013] The styrene content in component (A) is preferably 3 to 60% by weight, more preferably 5 to 50% by weight, and particularly preferably 10 to 40% by weight, and the viscosity of a 25% toluene solution at 25°C is preferably 50 to 30,000 mPa s, more preferably 100 to 20,000, and particularly preferably 150 to 10,000.

[0014] Specific examples of the component (A) include Kraton G 1650 (product name, Kraton Corporation, SEBS, styrene content: 30% by weight, 25% toluene solution viscosity (25°C): 8,000 mPa·s), Kraton G1652 (product name, Kraton Corporation, SEBS, styrene content: 30% by weight, 25% toluene solution viscosity (25°C): 1,800 mPa·s), Kraton G1726 (product name, Kraton Corporation, SEBS, styrene content: 30% by weight, 25% toluene solution viscosity (25°C): 200 mPa·s), and Kraton G 1730 (product name, Kraton Corporation, SEPS, styrene content: 20% by weight, 25% toluene solution viscosity (25°C): 1,980 mPa·s).

[0015] <Ethylene-vinyl acetate copolymer> In the present invention, an ethylene-vinyl acetate copolymer (B) is used. By using the component (B), it is possible to impart strength and flexibility to the component (A).

[0016] The vinyl acetate content in the component (B) is preferably from 1 to 50% by weight, more preferably from 2 to 40% by weight, and particularly preferably from 3 to 30% by weight.

[0017] The blending ratio of the (B) component is preferably 1 to 800 parts by weight, more preferably 5 to 500 parts by weight, even more preferably 10 to 100 parts by weight, and particularly preferably 15 to 60 parts by weight, per 100 parts by weight of the (A) component.

[0018] Specific examples of the component (B) include AC 400 (product name, manufactured by Honeywell, vinyl acetate content: 12 to 16% by weight), EVATHENE UE508 (product name, manufactured by USI, vinyl acetate content: 8% by weight), and EVA 1519 (product name, manufactured by Hanwha, vinyl acetate content: 19% by weight).

[0019] In the present invention, a Fischer-Tropsch wax (C) is used. Generally, wax is blended to impart plasticity, and types of wax include natural wax and synthetic wax. Examples of natural wax include paraffin wax and microcrystalline wax, and examples of synthetic wax include polyethylene wax and Fischer-Tropsch wax.

[0020] The inventors of the present application have discovered that by using component (C) among these, it is possible to suppress the penetration of low molecular weight oil components even when they come into contact with the composition, and have thus completed the present invention.

[0021] The softening point of the component (C) is preferably from 60 to 150°C, more preferably from 65 to 140°C, and particularly preferably from 70 to 130°C.

[0022] The blending ratio of the (C) component is preferably 1 to 500 parts by weight, more preferably 3 to 300 parts by weight, and particularly preferably 10 to 100 parts by weight, per 100 parts by weight of the (A) component.

[0023] Specific examples of the component (C) include SERATION 1810 (product name, manufactured by Sasol, softening point: 115-120°C), SERATION 1820 (product name, manufactured by Sasol, softening point: 110-115°C), SERATION 1830 (product name, manufactured by Sasol, softening point: 85-95°C), Sasolwax H1 (product name, manufactured by Sasol, softening point: 112°C), and Sasolwax C80 (product name, manufactured by Sasol, softening point: 88°C).

[0024] <Other ingredients> In the present invention, a tackifier can be used as another component. By using this component, the wettability of the adherend surface is increased, and therefore the adhesion between layers can be improved.

[0025] Examples of the component include terpene resins, terpene phenol resins, aliphatic petroleum resins, aromatic petroleum resins, alicyclic petroleum resins, rosin resins, and hydrogenated or modified products thereof.

[0026] The softening point of this component is preferably from 60 to 250°C, more preferably from 70 to 200°C, and particularly preferably from 80 to 180°C.

[0027] The blending ratio of this component is preferably 1 to 1000 parts by weight, more preferably 10 to 800 parts by weight, and particularly preferably 30 to 500 parts by weight, per 100 parts by weight of the component (A).

[0028] Specific examples of the component include YS Resin PX1250 (product name, manufactured by Yasuhara Chemical Co., Ltd., terpene resin, softening point: 120°C to 130°C), Tamanor 901 (product name, manufactured by Arakawa Chemical Co., Ltd., terpene phenol resin, softening point: 125°C to 135°C), Pine Crystal KR-85 (product name, manufactured by Arakawa Chemical Co., Ltd., rosin resin, softening point: 80°C to 87°C), Fuclear FM-100 (product name, manufactured by United Performance Material Co., Ltd., aliphatic hydrocarbon, softening point: 97°C to 103°C), T-REZ HA125 (product name, manufactured by JXTG Energy Corporation, alicyclic hydrocarbon, softening point: 120°C to 130°C), Eastotac C100R (product name, manufactured by Eastman Co., aliphatic petroleum resin, softening point: 100°C), and Escorez 5320 (product name, manufactured by ExxonMobil, aliphatic hydrocarbon, softening point: 124°C), and Endex 155 (product name, manufactured by Eastman, aromatic petroleum resin, softening point: 152°C).

[0029] Furthermore, in the present invention, an anti-aging agent can be used. Examples of the type of the component include phosphites, naphthylamines, p-phenylenediamines, quinolines, hydroquinones, bis-tris-polyphenols, thiobisphenols, and hindered phenols, and one or more of them can be used in combination. Specific examples of the component include Sumilizer GP (product name, manufactured by Sumitomo Chemical Co., Ltd.) and Songnox 1010 (product name, manufactured by Songwon Co., Ltd.).

[0030] The blending ratio of this component is preferably 0.01 to 30 parts by weight, more preferably 0.1 to 20 parts by weight, and particularly preferably 0.5 to 10 parts by weight, relative to 100 parts by weight of the above component (A). By having the type and blending ratio of this component within the above range, deterioration due to heat tends to be efficiently suppressed.

[0031] In the present invention, various additives such as fillers such as calcium carbonate, talc, and clay, preservatives, and moisture absorbents may be contained. EXAMPLES

[0032] <Examples and Comparative Examples> The hot melt compositions of the Examples and Comparative Examples were obtained by thoroughly melt-mixing the ingredients shown in Table 1 in a separable flask set at 180° C. Here, the numerical values ​​in Table 1 represent parts by weight. The raw materials used are shown below. Kraton G1652 (product name, Kraton Corporation, styrene-based thermoplastic elastomer (SEBS), 25% toluene solution viscosity (25°C): 1,800 mPa s) EVA 1519 (product name, Hanwha Corporation, ethylene-vinyl acetate copolymer, vinyl acetate content: 19% by weight) Sasolwax C80 (product name, Sasol, Fischer-Tropsch wax, softening point: 88°C) HNP-51 (product name, Nippon Seiro Co., Ltd., paraffin wax, melting point: 77°C) Microwax 80 (product name, Changge Huading Wax Industry Co., Ltd., microcrystalline wax, softening point: 76-78°C) Escorez 5320 (product name, ExxonMobil Corporation, tackifier (aliphatic hydrocarbon), softening point: 124°C) Eastotac C100R (product name, Eastman Co., tackifier (aliphatic petroleum resin), softening point: 100°C) Fuclear FM-100 (product name, United Performance Material, tackifier (aliphatic hydrocarbon), softening point: 97-103°C) Songnox 1010 (product name, Songwon, anti-aging agent)

[0033] [Table 1]

[0034] The hot melt compositions obtained in the above examples were subjected to the following physical property evaluations. The results are shown in Table 2.

[0035] <Melt viscosity> Using a Brookfield viscometer, 10 g of the hot melt composition was melted at 180°C and allowed to stand for 10 minutes at measurement temperatures of 160°C, 170°C, and 180°C. After this, rotation was started with a spindle No. 27 at a rotation speed of 5 rpm, and the melt viscosity (mPa s) after 10 minutes was measured.

[0036] <Softening point> The softening point of the hot melt composition was measured in accordance with JIS K 6883-1994.

[0037] <Tensile strength / tensile elongation> The hot melt composition was melted at 100°C to prepare a sheet with a thickness of 1 mm, and then a test piece having a dumbbell No. 3 shape was prepared according to JIS K 6251. The test piece was aged at 23°C for 24 hours, and then the tensile strength (MPa) and tensile elongation (%) of the test piece were measured at a tension speed of 100 mm / min in an atmosphere of 23°C and 50°C.

[0038] <Bleeding property> 30 parts by weight of Taipol 3206 (TSRC, styrene-butadiene-styrene block copolymer) and 70 parts by weight of Nyflex 223 (Nynas, naphthenic oil) were melted and mixed at 150°C to prepare a test resin. Next, the hot melt composition obtained in the examples was melted at 100°C to prepare a test film with a thickness of 150 μm. The test film was then laminated on a printing paper for copying (60 mm x 60 mm), a circular aluminum partition plate (diameter 29 mm, height 20 mm) was placed and fixed on top of it, the test resin was poured into it, and the test specimen was prepared by cooling at room temperature. After cooling, the test specimen was left to stand at 60°C for 24 hours, and the increase in the weight of the printing paper (mg / cm 2 ) was measured.

[0039] [Table 2]

[0040] The hot melt composition of Example 1 was found to have excellent strength and flexibility, and was also able to suppress the penetration of low molecular weight oil components even when it came into contact with them. On the other hand, when the hot melt composition of Comparative Example 1 was used, a small amount of oil components adhered to the fingers when the surface of the printed paper was touched after the bleeding test, and when the hot melt composition of Comparative Example 2 was used, a large amount of oil components adhered to the fingers.

Claims

1. The composition contains 1 to 100 parts by weight of an ethylene-vinyl acetate copolymer (B) and 1 to 100 parts by weight of a Fischer-Tropsch wax (C) relative to 100 parts by weight of a styrene-based thermoplastic elastomer (A), The styrene-based thermoplastic elastomer (A) contains at least one selected from the group consisting of styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene-ethylene / propylene-styrene block copolymer (SEPS), and styrene-ethylene-ethylene / propylene-styrene block copolymer (SEEPS), A hot melt composition characterized in that it is used in a film for packaging small pieces of hot melt adhesive.

2. 10. The hot melt composition of claim 1, further comprising a tackifier.

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