Hot Melt Composition

Abstract

To provide a hot melt composition which has a suitable melt viscosity and hence good workability, a comparatively high expansion ratio, good adhesion to inorganic materials after expansion, and excellent recovery property after compression. [Solution] A hot melt composition comprising a styrene-based block copolymer (A), a tackifier (B), and a softener (C), characterized in that the styrene-based block copolymer (A) comprises: a styrene-based block copolymer (a1) having a styrene content of 50% by weight or less and a diblock content of 35% by weight or less; and a styrene-based block copolymer (a2) having a styrene content of 50% by weight or less and a diblock content of 40% by weight or more.

Description

[Technical field]

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

[0002] Hot melt compositions have been widely researched and developed. Hot melt compositions melt when heated and solidify when cooled to room temperature of about 23°C, and are therefore suitable for use as adhesives. Their characteristics include being solvent-free, environmentally friendly, solidifying in a short time, and being a very easy-to-handle material, and because they can improve the working environment at manufacturing sites, they are widely used in a variety of fields.

[0003] In the past, the applicant of the present application invented a hot melt composition comprising a styrene block copolymer (A) and a tackifier (B), the styrene block copolymer (A) comprising a styrene block copolymer (a1) having a styrene content of less than 20% by weight and a diblock content of less than 22% by weight, and a styrene block copolymer (a2) having a styrene content of 20% by weight or more and a diblock content of 22% by weight or more (Patent Document 1). This hot melt composition maintained its stability after curing and had good coatability, so that no uneven coating or lumps occurred, and had excellent adhesive strength and heat resistance. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6906596

[0005] Traditionally, various adhesives have been used in the construction industry to fasten components together, but the use of hot melt compositions is on the rise because they are very easy to handle, do not require a drying process, and have excellent adhesive stability at room temperature of around 23°C.

[0006] Here, when applying a hot melt composition to attach an inorganic decorative material as an exterior material, there was a problem that the hardness was somewhat high and the application could not be performed well. Therefore, a method was adopted in which the hot melt composition was foamed little by little using a special device to give it a certain degree of flexibility before application. Therefore, the hot melt composition was required to have a relatively high foaming ratio and excellent adhesion to the inorganic decorative material after foaming. In addition, it was required to have high recovery after pressing so that the generation of unevenness on the application surface was suppressed even when pressed during application work, and there was room for improvement. Summary of the Invention [Problem to be solved by the invention]

[0007] The problem to be solved by the present invention is to provide a hot melt composition which has a suitable melt viscosity and therefore good workability, a relatively high expansion ratio, good adhesion to inorganic materials after expansion, and excellent recovery after compression. [Means for solving the problem]

[0008] The present invention provides a hot melt composition comprising a styrene-based block copolymer (A), a tackifier (B), and a softener (C), wherein the styrene-based block copolymer (A) comprises a styrene-based block copolymer (a1) having a styrene content of 50% by weight or less and a diblock content of 35% by weight or less, and a styrene-based block copolymer (a2) having a styrene content of 50% by weight or less and a diblock content of 40% by weight or more. Effect of the Invention

[0009] The hot melt composition of the present invention has an appropriate melt viscosity and therefore good workability, and also has the advantages of a relatively high expansion ratio, good adhesion to inorganic materials after expansion, and excellent recovery after compression. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] <Styrene-based block copolymer> In the present invention, a styrene-based block copolymer (A) is used as a base polymer for the hot melt composition according to the present invention.

[0011] Component (A) is composed of a hard block derived from a styrene compound and a soft block derived from a diene compound. The bonding form of each block can be linear, branched, or radial, but linear bonding is more prevalent.

[0012] The type of component (A) can be divided into "unhydrogenated styrene-based block copolymers" in which the soft block is not hydrogenated, and "hydrogenated styrene-based block copolymers" in which the soft block is hydrogenated. Examples of unhydrogenated styrene-based block copolymers include styrene-isoprene-styrene block copolymers (SIS) and styrene-butadiene-styrene block copolymers (SBS), while examples of hydrogenated styrene-based block copolymers include styrene-ethylene / butylene-styrene block copolymers (SEBS), styrene-ethylene / propylene-styrene block copolymers (SEPS), and styrene-ethylene-ethylene / propylene-styrene block copolymers (SEEPS). Among these, in the present invention, it is preferable to use hydrogenated styrene-based block copolymers because they have excellent adhesion stability and durability.

[0013] In the present invention, it is necessary to use a styrene-based block copolymer (a1) having a styrene content of 50% by weight or less and a diblock content of 35% by weight or less, and a styrene-based block copolymer (a2) having a styrene content of 50% by weight or less and a diblock content of 40% by weight or more.

[0014] By appropriately adjusting the styrene content and diene content of the (A) component, hot melt compositions with various properties can be produced. In general, the higher the styrene content, the higher the rigidity, and the lower the styrene content, the higher the flexibility. In the present invention, the styrene content of the (A) component must be 50% by weight or less, preferably 10 to 45% by weight, more preferably 15 to 40% by weight, and particularly preferably 20 to 35% by weight. By being within this range, a hot melt composition with high flexibility can be produced while maintaining a certain degree of rigidity.

[0015] The diblock ratio of the (a1) component must be 35% by weight or less, preferably 25% by weight or less, more preferably 15% by weight or less, and particularly preferably 5% by weight or less. By being within this range, the recovery property after foaming of the hot melt composition tends to be improved.

[0016] Specific examples of the (a1) component include Taipol 6152 (product name, manufactured by TSRC, styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene content: 30% by weight, diblock content: less than 1% by weight).

[0017] The diblock ratio of the (a2) component must be 40% by weight or more, preferably 50% by weight or more, more preferably 55% by weight or more, and particularly preferably 60% by weight or more. By being within this range, the expansion ratio tends to increase and the adhesion to inorganic materials tends to improve.

[0018] Specific examples of the (a2) component include GLOBALPRENE 9526D (product name, manufactured by LCY, styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene content: 30% by weight, diblock content: 70% by weight).

[0019] The inventors of the present invention found that the use of components (a1) and (a2) together results in good adhesion to inorganic materials after foaming and excellent recovery after compression, and thus completed the present invention. One of the factors that produces such an effect is presumably that the combined use of components (a1) and (a2) generates intermolecular internal friction in the entanglement of carbon chains in the soft blocks of component (A), which makes it easier to dissolve with other components, thereby allowing the gas introduced during foaming to be efficiently dispersed.

[0020] The blending ratio (parts by weight) of the (a1) component to the (a2) component in the (A) component is preferably 1:0.1 to 10, more preferably 1:0.2 to 5, and particularly preferably 1:0.25 to 4. By blending within this range, the physical properties of the hot melt composition according to the present invention tend to be further improved.

[0021] <Tackifier> In the present invention, a tackifier (B) is used. Examples of the type of component (B) include terpene resins, terpene phenol resins, rosin resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, alicyclic hydrocarbon resins, and hydrogenated or modified products thereof.

[0022] The softening point of the component (B) is preferably from 60 to 250°C, more preferably from 70 to 200°C, and particularly preferably from 80 to 180°C.

[0023] The blending ratio of the (B) component is preferably 10 to 1000 parts by weight, more preferably 20 to 500 parts by weight, and particularly preferably 30 to 300 parts by weight, per 100 parts by weight of the (A) component.

[0024] Specific examples of the component (B) include YS Resin PX1250 (trade name, manufactured by Yasuhara Chemical Co., Ltd., terpene resin, softening point: 120°C to 130°C), Tamanor 803L (trade name, manufactured by Arakawa Chemical Industries Co., Ltd., terpene phenol resin, softening point: 145°C to 160°C), Pine Crystal KR-85 (trade name, manufactured by Arakawa Chemical Industries Co., Ltd., rosin resin, softening point: 80°C to 87°C), YL120 (trade name, manufactured by Yuen Liang Industrial Co., Ltd., aromatic hydrocarbon resin, softening point: 115°C to 125°C), and T-REZ HA125 (trade name, manufactured by ENEOS Corporation, hydrogenated alicyclic hydrocarbon resin, softening point: 120°C to 130°C).

[0025] <Softener> In the present invention, a softener (C) is used. Examples of the (C) component include an organic compound (c1) that is liquid at room temperature (23°C) and an organic compound (c2) that is solid. By using the (C) component, the dispersibility of the (A) and (B) components is improved, so that the wettability of the adherend surface can be increased and the adhesion between the layers can be improved. In particular, by using the (c1) and (c2) components in combination, it becomes easier to adjust the melt viscosity within an appropriate range and flexibility can be imparted, which tends to further improve workability.

[0026] The types of component (c1) include paraffinic oil, naphthenic oil, polybutene, polyisobutylene, liquid paraffin, etc. Among these, paraffinic oil and naphthenic oil are preferably used because they are highly stable and easy to handle.

[0027] A specific example of the component (c1) is Diana Process Oil PW-90 (product name, paraffinic oil, manufactured by Idemitsu Kosan Co., Ltd., kinematic viscosity (40°C): 91 mm 2 / s), Diana Process Oil NP-250 (product name, paraffinic / naphthenic mixed oil, manufactured by Idemitsu Kosan Co., Ltd., kinematic viscosity (40°C): 275 mm 2 / s), Lily 500 (product name, Kudong, paraffin oil, kinematic viscosity (40℃): 107mm 2 / s) etc.

[0028] Moreover, the type of component (c2) can be wax, which can be either natural or synthetic wax. Natural waxes include paraffin wax and microcrystalline wax, and synthetic waxes include polyethylene wax and polypropylene wax.

[0029] Specific examples of the (c2) component include Hiwax NP500 (product name, manufactured by Mitsui Chemicals, Inc., polypropylene wax, melting point: 161°C), H-110 (product name, manufactured by SQI Thailand, polyethylene wax, melting point: 110°C), and UMEX 1010 (product name, manufactured by Sanyo Chemical Industries, Ltd., maleic anhydride modified polypropylene wax, melting point: 135°C).

[0030] The blending ratio of the (C) component is preferably 10 to 1,500 parts by weight, more preferably 30 to 1,000 parts by weight, and particularly preferably 50 to 600 parts by weight, per 100 parts by weight of the (A) component.

[0031] In the present invention, an antioxidant can be used as an additive. Examples of the components include phosphites, naphthylamines, p-phenylenediamines, quinolines, hydroquinones, bis-tris-polyphenols, thiobisphenols, and hindered phenols, and one or more of these can be used in combination. Specific examples of the components include Sumilizer GP (trade name, manufactured by Sumitomo Chemical Co., Ltd.), Songnox 1010 (trade name, manufactured by Songwon Co., Ltd.), and Chinox 1010 (trade name, manufactured by Double Bond Chemical Co., Ltd.).

[0032] In addition, in the present invention, various additives such as fillers such as calcium carbonate, talc, and clay, preservatives, and colorants may be contained.

[0033] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these descriptions. EXAMPLES

[0034] <Examples and Comparative Examples> The hot melt compositions of the Examples and Comparative Examples were produced by thoroughly kneading the ingredients in the formulation shown in Table 1 in a flask adjusted to 180° C. Here, the numerical values ​​in Table 1 represent parts by weight. The raw materials used are shown below. Taipol 6152 (product name, manufactured by TSRC, styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene content: 30% by weight, diblock content: less than 1% by weight) GLOBALPRENE 9526D (product name, manufactured by LCY, styrene-ethylene / butylene-styrene block copolymer (SEBS), styrene content: 30% by weight, diblock content: 70% by weight) YL120 (product name, manufactured by Yuen Liang Industrial Co., Ltd., aromatic hydrocarbon resin, softening point: 115 to 125°C) Lily 500 (product name, Kudong, paraffin oil, kinematic viscosity (40℃): 107mm 2 / s) H-110 (product name, manufactured by SQI Thailand, polyethylene wax, melting point: 110°C) Chinox 1010 (trade name, manufactured by Double Bond Chemical, antioxidant)

[0035] [Table 1]

[0036] The hot melt compositions produced in the above examples were evaluated for various physical properties in the following manner. The results are shown in Table 2.

[0037] <Melt viscosity> The hot melt composition was melted at 180°C and left to stand for 10 minutes, then rotation was started at 5 rpm with a spindle No. 27, and the melt viscosity (mPa s) was measured after 10 minutes using a Brookfield viscometer. If the melt viscosity was 1,000 mPa s or more and 7,000 mPa s or less, the workability was determined to be good.

[0038] <Softening point> The softening point (° C.) of the hot melt composition was measured in accordance with JIS K 6863.

[0039] <Foaming method / Foaming ratio> Using a foam melter FM200 (manufactured by Nordson Corporation), the hot melt composition was foamed at the following conditions: system temperature (tank, hose, nozzle): 180°C, gas used: nitrogen, pump speed: 450 rpm, gas pressure: 2 psi, system pressure: 340 to 360 psi. The foamed hot melt composition was poured into a 50 cc paper cup, its weight (g) was measured, and the foaming ratio (times) was calculated by the following formula. If the foaming ratio was 2.0 times or more, it was determined that the foaming ratio was high. Expansion ratio (times) = weight (g) of hot melt composition before foaming / weight (g) of hot melt composition after foaming

[0040] <Adhesive strength> The hot melt composition foamed under the above-mentioned foaming conditions was applied to the cement substrate and the glass substrate in a bead shape (width: 2 mm) at a line speed of 10 m / min, and left to stand for 24 hours at a temperature of 23°C and a humidity of 50% to solidify. The solidified hot melt composition was then pulled vertically with a spring-loaded hand balance, and its maximum strength (gf) was measured. If the measured value was 60 gf or more for both substrates, it was determined that the adhesive strength was excellent.

[0041] <Resiliency> The hot melt composition foamed under the above-mentioned foaming conditions was discharged into a mold release box and left to stand for 24 hours at a temperature of 23°C and a humidity of 50% to solidify. The solidified hot melt composition was then released from the mold and cut into a block shape of 20 mm x 5 mm x 10 mmt using a heat cutter to prepare a test piece. This test piece was left to stand in a thermostatic chamber adjusted to 40°C and left for 1 hour. Then, the test piece was compressed (a test piece with a thickness of 10 mm was compressed until it became 3 mm thick) for 10 seconds at a temperature of 40°C, and the thickness t (mm) of the test piece after being released for 10 seconds was measured. If the thickness t (mm) of the test piece was 7 mm or more, it was determined that the restorability was good.

[0042] [Table 2]

[0043] When hot melt compositions according to the Examples and Comparative Examples were produced using various styrene-based thermoplastic elastomers, the melt viscosity at 180°C, softening point, and expansion ratio were comparable, but the Examples showed better adhesion to inorganic materials after expansion and also had better recovery after compression than the Comparative Examples.

Claims

1. Contains a styrene-based block copolymer (A), a tackifier (B), and a softener (C), As the styrene-based block copolymer (A), a styrene-based block copolymer (a1) having a styrene content of 50% by weight or less and a diblock ratio of 35% by weight or less; A styrene-based block copolymer (a2) having a styrene content of 50% by weight or less and a diblock ratio of 40% by weight or more, A hot melt composition for construction, characterized in that the blending ratio (parts by weight) of the (a1) component to the (a2) component is 1:0.1-10.

2. The hot melt composition according to claim 1, characterized in that it is used as an architectural exterior material.

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