JP5572510B2 - Hot melt composition - Google Patents

Description

  The present invention relates to a hot melt composition having high heat resistance, low viscosity, excellent elasticity, and suitable as various sealing materials.

  The hot melt composition is a resin composition mainly composed of a thermoplastic resin, and it has excellent initial adhesive strength because it exhibits adhesive strength when cooled and solidified, and has advantages such as being environmentally friendly and easy to handle because it does not contain a solvent. Therefore, it is used for various sealing materials.

  The hot melt composition is also used as a sealing material for automotive parts. However, it is required to have heat resistance because it is used at high temperatures in summer, but it also follows movements such as expansion, contraction, and warping of the substrate. There is also a demand for flexibility to maintain the sealing function. Moreover, since workability | operativity falls when a viscosity is too high at the time of application | coating of a sealing material, it is also requested | required that melt viscosity is low.

Patent Document 1 discloses an elastic resin composition useful for sealing a frame of an electronic control unit for automobiles. This is excellent in heat resistance, but lacks flexibility to follow the movement of the substrate.
JP 2008-285612 A

  An object of the present invention is to provide a hot melt composition having high heat resistance, low viscosity, excellent elasticity, and suitable as various sealing materials.

  As a result of studies by the present inventor, it has been found that it is indispensable to use a styrenic block copolymer in combination because butyl rubber having excellent flexibility does not have sufficient heat resistance. However, the combined use of styrene block copolymers has faced the problem of increased viscosity and reduced flexibility. As a result of further extensive studies, it was found that when a specific amount of an aromatic modified terpene resin was blended in addition to the butyl rubber and styrene block copolymer, all of heat resistance, viscosity and flexibility could be satisfied. The present invention has been completed.

The present invention relates to a butyl rubber (a) having a Mooney viscosity of 20 to 90 and an unsaturation degree of 0.5 to 5.0, a styrene block copolymer (b), an aromatic modified terpene resin (c) , an inorganic The filler (d) is contained, the blending amount of the butyl rubber (a) is 10 to 30% by weight with respect to the whole sealing material, and the blending amount of the aromatic modified terpene resin (c) with respect to 100 parts by weight of the butyl rubber (a). Is 10 to 50 parts by weight, the blending amount of the inorganic filler (d) is 1 to 50% by weight with respect to the whole sealing material, does not contain paraffin wax, and has a melt viscosity (0.5 rpm) at 150 ° C. 1000 Pa. s or less, and the heat resistance evaluation of the heat drooping property based on JASOM 323 9.42 (established by the Japan Automobile Technical Association, heat drooping test) is 40 ° C. or more, and JASOM 323 is 9.7 (corporate car) It is a sealing material for automobile members, characterized by having a penetration of 60 or more based on (Technical Association establishment, heat sag test) .

  The hot melt composition of the present invention has high heat resistance, follows the movement of the base material such as expansion, contraction, warpage, etc., and has flexibility to maintain the sealing function. Suitable for. Moreover, since the viscosity is low, the coating workability is excellent.

  Hereinafter, each essential component of the hot melt composition used in the present invention will be described. Butyl rubber (a) is blended in the present hot melt composition for the purpose of imparting sealing properties, weather resistance, water resistance, flexibility, impact absorption, etc., has a Mooney viscosity of 20 to 90, and is unsaturated. A degree of about 0.5 to 5.0 is preferable. The blending amount of butyl rubber is preferably 10 to 30% by weight with respect to the entire hot melt composition.

  In the present invention, the styrenic block copolymer (b) is blended mainly for ensuring heat resistance. In order to ensure elasticity and cohesive force, those having an average molecular weight of 30,000 to 500,000 are suitable. Specifically, styrene-isoprene-styrene block copolymer (SIS), styrene-butadiene-styrene block copolymer. (SBS), styrene-ethylene-butadiene-styrene block copolymer (SEBS), α-methylstyrene-butadiene-α-methylstyrene block copolymer, α-methylstyrene-isoprene-α-methylstyrene block copolymer These hydrogenated modified products include, for example, styrene-ethylene- (ethylene-propylene) -styrene block copolymer (SEEPS), styrene-ethylene-propylene-styrene block copolymer (SEPS), and the like.

In the present invention, the aromatic modified terpene resin (c) is added in order to lower the melt viscosity of the hot melt composition and maintain flexibility. It is a resin obtained by a method such as polymerization. These may be used alone or in combination of two or more.
The compounding amount of the aromatic modified terpene resin needs to be 10 to 50 parts by weight with respect to 100 parts by weight of the butyl rubber, and more preferably 15 to 35 parts by weight.
When the blending amount of the aromatic modified terpene resin is small, workability is lowered because the melt viscosity of the hot melt composition cannot be lowered sufficiently. Moreover, when there are many aromatic modified terpene resins, heat resistance falls remarkably.

  The hot melt composition of the present invention includes various additives such as tackifier resins, liquid resins, α-olefin resins, inorganic fillers, antioxidants, silane coupling agents, pigments, etc. Can be blended. Examples of tackifying resins include terpene resins, rosin resins, hydrogenated rosin resins, petroleum resins, and hydrogenated petroleum resins. Specific examples of the liquid resin include liquid polybutadiene and liquid polybutene.

  The inorganic filler is added for the purpose of improving the heat resistant flow property. Specific examples include calcium carbonate, talc, clay, silica, titanium oxide and the like. It is preferable that the compounding quantity of an inorganic filler shall be 1-50 weight% with respect to the whole hot-melt composition. When it is 1% by weight or more, the heat resistant flow property is remarkably exhibited, and when it is less than 50% by weight, there is little possibility that the melt viscosity becomes too high.

  Antioxidants include copper-based antioxidants, copper salt-based antioxidants, copper halide-based antioxidants, phosphorus-based antioxidants, phenol-based antioxidants, hindered amine-based antioxidants, sulfur-based antioxidants Examples thereof include a metal deactivator comprising an inhibitor, a lactone-based antioxidant, an aromatic amine, and a chelating agent.

  Examples of phenolic antioxidants include 2,6-di-t-butylphenol derivatives, 2-methyl-6-t-butylphenol derivatives, octadecyl-3- (3,5-dibutyl-4-bitoxyphenyl) propionate, 4 , 4-Butylidene-bis (6-t-butyl-m-cresol), pentaerythrityl tetrakis {3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate}, 2- {1- (2-hydroxy-3,5-di-t-pentylphenyl) -ethyl} -4,6-di-t-pentylphenyl acrylate and the like.

  Phosphorus antioxidants include tris (2,4-di-t-butylphenyl) phosphate, cyclic neopentanetetrabis (2,4-di-t-butylphenyl phosphate, dostearyl pentane erythritol diphosphate , Sodium dihydrogen phosphate, and disodium monohydrogen phosphate.

  Examples of hindered amine antioxidants include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1 , 2,3,4-Tetrakis (2,2,6,6-tetramethyl-4-piperidyloxycarbonyl) butane, dimethyl-1- (2-hydroxylethyl-4-hydroxy-2,2,6, succinate) 6-tetramethylpiperidine polycondensate, 1- (3,5-di-t-butyl-4-hydroxyphenyl) -1,1-bis (2,2,6,6-tetramethyl-4-piperidyloxycarbonyl) ) Pentane, N, N-bis (3-aminopropyl) ethylenediamine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, bis (octylone-2,2,6, - tetramethyl-4-piperidyl) sebacate, and the like.

The hot melt composition can be obtained by kneading the above-described blended components with a Banbury mixer, a heating kneader, a uniaxial to biaxial extruder, or the like. The melt viscosity of the hot melt composition is preferably 3000 Pa · s or less at 200 ° C., and 2000 Pa
-More preferably, it is s or less. When it exceeds 3000 Pa · s at 200 ° C., the coating property is deteriorated, so that it takes time for the coating operation, and the load is increased in a general-purpose coating device, so that the damage to the device is accelerated. Moreover, if the melting temperature is raised, the melt viscosity is lowered, but the hot melt composition is likely to deteriorate, which is not preferable.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not restrict | limited to these Examples.

Production of hot melt composition: Butyl 402 (trade name, manufactured by LANXESS BUTYL Co., Ltd.) as butyl rubber, 14 parts by weight, Kraton G1726 (trade name, manufactured by Kraton Polymer Japan Co., Ltd.) as SEBS, 2.5 parts by weight, aromatic modified terpene resin 2.4 parts by weight of Sylvares TP2019 (trade name, manufactured by Arizona Chemical Co., Ltd.), a terpene phenol resin having a softening point of 125 ° C. Name) 2.4 parts by weight, Vestplast 888 (product name of Evonik Degussa Japan Co., Ltd.), which is an amorphous α-olefin resin having a softening point of 161 ° C., 2.5 parts by weight, BF200 (product of Shiraishi Calcium Co., Ltd.) which is calcium carbonate, (Product name) 40 parts, sumilizer GP (product name) manufactured by Kyodo Yakuhin Co., Ltd. Heated by weight, 0.7 parts by weight of Weston 618F (trade name, manufactured by GE) and 35 parts by weight of HV300 (trade name, manufactured by Nippon Petrochemical Co., Ltd.), a liquid polybutene, with a sigma blade type kneader The hot melt composition of Example 1 was obtained by mixing. Similarly, each hot melt composition of Comparative Examples 1 and 2 was obtained with the formulation shown in Table 1. Each hot melt composition was evaluated by the following method.

Melt viscosity The melt viscosity (150 rpm) in 150 degreeC was measured using the digital viscometer (model | form: DVI-I +) by Brookfield. Melt viscosity is 1000 Pa. If it is s or less, the workability is less affected.

Heat resistance (heat drooping)
The heat drooping property was evaluated based on JASO M323 9.42 (established by the Society of Automotive Engineers of Japan, heat drooping property test). As an outline of the test, the hot melt composition is attached with a holder so as to hang vertically in the incubator, the temperature is increased at a rate of 5 ° C. from 30 ° C. for 10 minutes, and the suspended portion hangs 10 mm from the initial stage. The temperature is measured. It has sufficient heat resistance in heat resistance evaluation being 40 degreeC or more.

Penetration The penetration was evaluated based on JASO M323, 9.7 (established by the Japan Society for Automotive Engineers, heat droop test). When the penetration is 60 or more, sufficient flexibility is provided.

  The hot melt composition of Example 1 was excellent in all of heat resistance, flexibility, and workability. Further, Comparative Example 1 containing no styrenic block copolymer has insufficient heat resistance, and Comparative Example 2 has improved heat resistance, but lacked flexibility and workability.

Claims (1)

Butyl rubber (a) having a Mooney viscosity of 20 to 90 and an unsaturation degree of 0.5 to 5.0, a styrenic block copolymer (b), an aromatic modified terpene resin (c) , an inorganic filler (d ) , The blending amount of the butyl rubber (a) is 10 to 30% by weight with respect to the whole sealing material, and the blending amount of the aromatic modified terpene resin (c) with respect to 100 parts by weight of the butyl rubber (a) is 10 to 50%. Parts by weight, the blending amount of the inorganic filler (d) is 1 to 50% by weight with respect to the whole sealing material, no paraffin wax is included, and the melt viscosity at 150 ° C. (0.5 rpm) is 1000 Pa.s. s or less, and the heat resistance evaluation of the heat drooping property based on JASOM 323 9.42 (established by the Japan Automobile Technical Association, heat drooping test) is 40 ° C. or more, and JASOM 323 is 9.7 (corporate car) A sealing material for automobile members, characterized by having a penetration of 60 or more based on a technical association established and a heat sag test.