JP6635367B2 - Black brightener used in black polymer composition - Google Patents

Description

  The present invention relates to a black brightening agent which gives a black polymer composition having excellent black gloss over time.

  It is known that a black polymer composition such as a rubber composition deteriorates with time due to the influence of ultraviolet rays in sunlight. Therefore, measures for preventing the black polymer composition from deteriorating with time have been conventionally proposed. For example, it is known that a rubber composition is blended with petroleum wax to prevent deterioration (for example, Patent Document 1).

JP 2006-328144 A

  However, in a conventional black polymer composition using petroleum wax, as a result of blooming with petroleum wax, the surface is whitened over time and black gloss is likely to be reduced. The present invention has been made in view of such a conventional situation, and an object of the present invention is to provide a black brightening agent which gives a black polymer composition having excellent black gloss over time.

  The black brightening agent according to the present invention contains carnauba wax and grass of the family Poaceae, and is used by being blended into a black polymer composition.

  In the invention of the above black brightening agent, the weight ratio of the carnauba wax to the grass of the grass family is 80:20 to 40:60; the carnauba wax is a deoxidized carnauba wax; A carnauba wax as a raw material, which is heated and melted in a nitrogen gas atmosphere, p-toluenesulfonic acid is added as a catalyst to react and deoxidize the carnauba wax; the carnauba wax is an untreated carnauba wax; Additional requirements include that the plant wax is a gramineous wax; the gramineous wax is a hydrogenated gramineous wax; and the gramineous wax is rice bran wax. It is a thing.

The black polymer composition according to the present invention contains a polymer component and the above-mentioned black brightening agent.
The black molded body according to the present invention is obtained by molding the above black polymer composition.

  ADVANTAGE OF THE INVENTION According to this invention, the black gloss agent which provides the black polymer composition excellent in black gloss with time can be provided.

  Further, the black molded article obtained from the black polymer composition containing the black brightener according to the present invention has an excellent effect that, even when used for a long time, the surface is kept black and glossy, and good appearance can be maintained. To play.

Next, the present invention will be described in detail based on specific embodiments.
The black brightener according to the present invention contains carnauba wax and gramineous plant wax, and is used by being blended into a black polymer composition. Each of carnauba wax and gramineous plant wax can be used alone or in combination of two or more.

  The weight ratio of the carnauba wax to the grass wax is not particularly limited, and is preferably 80:20 to 40:60, more preferably 70:30 to 50:50, and still more preferably 60:50. 40. When the weight ratio is 80:20 to 40:60, the resulting black polymer composition containing the black brightener tends to have particularly excellent black gloss over time. When the weight ratio is 80:20 to 40:60, the obtained black brightener tends to have particularly good physical properties such as melting point, viscosity, and specific gravity, and tends to be particularly excellent in handleability and the like. .

  The carnauba wax is not particularly limited, and includes, for example, waxes having the following general properties: an acid value of 10 or less, a saponification value of 78 to 95, an iodine value of 5 to 14, a melting point of 80 to 88 ° C, and 25. The degree of penetration at 100C is 1 or less, the viscosity at 100C is 20 to 23 cP, the specific gravity at 25C is 0.995 to 0.999, and the flash point is 316 to 320C. The carnauba wax is not particularly limited, and may be an untreated carnauba wax, a deoxidized carnauba wax, or a combination thereof. It is preferable to use deoxidized carnauba wax because it is likely to be excellent in black glossiness. The deoxidized carnauba wax is not particularly limited, and includes, for example, those obtained by heating and melting a crude carnauba wax in a nitrogen gas atmosphere, and adding and reacting p-toluenesulfonic acid as a catalyst to deoxidize the carnauba wax. Specifically, there can be mentioned those obtained by the method described in Japanese Patent No. 281097 pertaining to a patent for which the present applicant is the patentee.

  The above-mentioned grass wax is not particularly limited. Even if it is a grass wax that has not been hydrogenated (that is, it is used without hydrogenation, it is used as it is). Even if it is, a combination of these may be used, and the resulting black polymer composition containing the black brightening agent tends to be excellent in black gloss over time, so that a non-hydrogenated grass wax is added. preferable. In particular, when a deoxidized carnauba wax and a non-hydrogenated grass wax are used in combination, the resulting black polymer composition containing the black brightener is a black polymer composition containing a conventionally used petroleum wax. Compared with the polymer composition, weather resistance and ozone resistance are likely to be almost equal or slightly improved, and the degree of discoloration or cracking is less likely to increase even under the same conditions as those exposed to the outside air .

  Specific examples of the above-mentioned rice wax include rice bran wax, sugarcane wax and the like. The rice bran wax is not particularly limited, and includes, for example, waxes having the following general properties: an acid value of 13 or less, a saponification value of 75 to 90, an iodine value of 10 or less, and a melting point of 65 to 82 ° C at 25 ° C. Penetration: 4 to 6, viscosity at 100 ° C: 13 to 16 cP, specific gravity at 25 ° C: 0.970 to 0.980, flash point: 298 to 302 ° C. Examples of commercially available rice bran wax include those manufactured by Sanwa Yushi Co., Ltd. or Bosso Yushi Co., Ltd. Sugarcane wax is a wax derived from sugarcane and has properties similar to those of rice bran wax.

  Natural waxes such as carnauba wax and gramineous wax (for example, rice bran wax and sugarcane wax) have melting points in the range of 60 ° C. to 90 ° C. and have relatively sharp peaks in DSC, so that they are easily melted and solidified. It is easy.

  The blackening agent according to the present invention may contain other components, for example, other vegetable waxes such as candelilla wax, mokurou, urushi wax and palm wax as long as the effects of the present invention are not impaired.

  The black polymer composition containing the black brightening agent according to the present invention is a black composition containing a polymer and has excellent black gloss over time. Specifically, the black polymer composition contains a polymer component and the black brightener according to the present invention. The method for imparting black color to the black polymer composition is not particularly limited, and examples thereof include a method of blending a black colorant, for example, a black pigment such as carbon black, as a component of the composition. That is, the black polymer composition may further contain a black colorant. The polymer component is not particularly limited as long as it is a high molecular compound, and examples thereof include a resin and a rubber component. The resin is not particularly limited. For example, thermoplastic resins such as polyethylene, polypropylene, polyvinyl chloride, polystyrene, polyvinyl acetate, polyurethane, and acrylic resin; thermosetting resins such as epoxy resin, phenol resin, melamine resin, and urea resin Resin. Examples of the rubber component include natural rubber, petroleum rubber, and synthetic rubber containing various plastics and the like, and include all rubber components conventionally used in rubber compositions. The black polymer composition may further contain various components, for example, silica, sulfur, a vulcanization accelerator and the like. Examples of the black polymer composition include a black polymer composition containing a resin and the black brightener according to the present invention, and a black polymer composition containing a rubber component and the black brightener according to the present invention. .

  In the black polymer composition in which the black brightener according to the present invention is blended, the content of the black brightener is preferably 0.1 to 10 parts by weight, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the polymer component. Is 0.5 to 5.0 parts by weight, still more preferably 1.0 to 3.0 parts by weight. When the content of the black brightening agent is within the above range, the obtained black polymer composition tends to be more excellent in black gloss over time, and the other physical properties hardly deteriorate with time. The black polymer composition can be prepared, for example, by uniformly mixing the black brightener according to the present invention and the polymer component using a stirrer such as a mixer.

  By molding the above black polymer composition, a black molded article having excellent black gloss over time can be obtained. Examples of the black molded article according to the present invention include a black molded article containing the above black polymer composition, and in particular, a black molded article made of the above black polymer composition.

  Specific examples of the black polymer composition include a rubber composition containing a diene rubber component and the black brightener according to the present invention, and more specifically, 100 parts by weight of the diene rubber component and the present invention. And a rubber composition containing 0.1 to 10 parts by weight of the black brightener according to the present invention. The diene rubber component in these rubber compositions corresponds to the polymer component in the black polymer composition.

  The diene rubber component of the rubber composition comprises a natural rubber and / or a synthetic diene rubber, and examples of the synthetic diene rubber include an aromatic vinyl compound-conjugated diene compound copolymer and a conjugated diene compound polymer. Can be The aromatic vinyl compound-conjugated diene compound copolymer or conjugated diene compound polymer is produced by copolymerizing an aromatic vinyl compound and a conjugated diene compound or polymerizing a conjugated diene compound. Here, as the conjugated diene compound as a monomer, 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 2-phenyl-1,3-butadiene, 1,3-hexadiene And the like. On the other hand, examples of the aromatic vinyl compound as a monomer include styrene, p-methylstyrene, m-methylstyrene, p-tert-butylstyrene, α-methylstyrene, chloromethylstyrene, and vinyltoluene. These monomers may be used alone or in combination of two or more.

  Specific examples of the synthetic diene rubber include polyisoprene rubber (IR), styrene-butadiene copolymer rubber (SBR), polybutadiene rubber (BR), chloroprene rubber (CR), butyl rubber (IIR), and halogenated butyl rubber. No. The rubber composition preferably uses natural rubber (NR), polybutadiene rubber (BR), polyisoprene rubber (IR), or styrene-butadiene copolymer rubber (SBR) for a tire.

  The rubber composition preferably contains a filler, and preferably contains carbon black and / or silica. The compounding amount of carbon black and / or silica is preferably 4 to 150 parts by weight based on 100 parts by weight of the diene rubber component. When the amount is 4 parts by weight or more, the fracture characteristics and wear resistance of the vulcanized rubber are excellently obtained, and when the amount is 150 parts by weight or less, the workability does not deteriorate.

  The carbon black that can be used is not particularly limited, and examples thereof include FEF, SRF, HAF, ISAF, and SAF grades. As such a carbon black, a carbon black having an iodine adsorption amount (IA) of 30 mg / g or more and a dibutyl phthalate (DBP) oil absorption of 80 mL / 100 g or more is preferable. By blending carbon black, various physical properties of the rubber composition can be improved. However, from the viewpoint of improving fuel efficiency and abrasion resistance, those of GPF, FEF, HAF, ISAF, and SAF grades are further used. preferable.

  The silica that can be used is not particularly limited, and examples thereof include wet silica (hydrous silicic acid), dry silica (silicic anhydride), calcium silicate, and aluminum silicate.

  In the rubber composition, as other optional components, compounding agents usually used in the rubber industry, for example, softeners, antioxidants, silane coupling agents, vulcanization accelerators, vulcanization accelerators, vulcanization Agents and the like can be appropriately selected and blended within a range that does not impair the purpose of the present invention. Commercially available products can be suitably used as these compounding agents. The rubber composition can be produced by compounding various compounding agents, kneading with a Banbury mixer, a roll, an intensive mixer, a twin-screw extruder, or the like, heating, extruding, or the like.

  Hereinafter, the present invention will be described in more detail with reference to Examples of the present invention, but the present invention is not limited to the following Examples.

[Preparation of unvulcanized rubber composition]
168 parts by weight of the following rubber mixture are charged into a required mixer, 2 parts by weight of a natural wax or petroleum wax described below are charged, and the mixture is kneaded for about 5 minutes so that the discharge temperature becomes 150 ° C. 0.8 parts by weight of a sulfur accelerator (Nouchira NS, manufactured by Ouchi Shinko Chemical Co., Ltd.) and 1.5 parts by weight of sulfur are added, and the mixture is kneaded for about 3 minutes so that the discharge temperature becomes 100 ° C. A vulcanized rubber composition was obtained.

Rubber mixture 30 parts by weight of natural rubber (RSS-3), 70 parts by weight of polybutadiene rubber (BR01, manufactured by JSR Corporation), 50 parts by weight of carbon black (N550 carbon, Asahi # 65, manufactured by Asahi Carbon Co., Ltd.) 10 parts by weight of an aromatic oil (process oil, manufactured by Fujikosan Co., Ltd., Fukkol Aromax 3B), 2 parts by weight of stearic acid, 3 parts by weight of zinc white, and an antioxidant (manufactured by Ouchi Shinko Chemical Co., Ltd. Nocrack 6C) mixture containing 3 parts by weight

-Natural wax or petroleum wax Comparative example 1: petroleum wax (conventional product, Ozoace 0280, manufactured by Nippon Seiro Co., Ltd.)
Example 1: Combination (weight) of deoxidized carnauba wax-CN (product name, deoxidized carnauba wax manufactured by Cerarika Noda Co., Ltd.) and non-hydrogenated rice bran wax (rice wax SS-II manufactured by Boso Oil & Fats Co., Ltd.) (Ratio 60:40)
Example 2: Combination of deoxidized carnauba wax-CN and hydrogenated rice bran wax (Rice wax SS-I, manufactured by Boso Oil & Fats Co., Ltd.) (weight ratio: 60:40)
Example 3: Untreated Carnauba wax-CN (product name, manufactured by Cera Rica Noda Co., Ltd., Carnauba wax before deoxidizing the above deoxidized carnauba wax-CN) and rice bran without hydrogenation (manufactured by Sanwa Yushi Co., Ltd.) , Lightol) (weight ratio 60:40)
Comparative Example 2: Deoxidized carnauba wax-CN only

[Evaluation of ozone resistance]
According to JIS K 6259: 2004, vulcanized rubber test pieces were prepared (vulcanization temperature: 160 ° C., vulcanization time: 20 minutes) and ozone resistance was evaluated. Specifically, by observing the state of deterioration of the test piece after being left for 50 hours under the conditions of a temperature of 40 ° C., an ozone concentration of 50 pphm, and an elongation of 2%, that is, by observing the state of a crack generated in the test piece, The ozone properties were evaluated. Using Comparative Example 1 using petroleum wax as a control, it was observed whether the state of the cracks was equivalent to Comparative Example 1 or worse than Comparative Example 1. Table 1 shows the results.

[Evaluation of discoloration resistance]
Using a chromaticity meter (Model NF333, manufactured by Nippon Denshoku Industries Co., Ltd.), the L * value of the vulcanized rubber test piece prepared in the same manner as above was measured, and the degree of discoloration was evaluated as follows. . The L * value indicates lightness. First, the L * value of the test piece immediately after vulcanization was measured. Next, the L * value of the test piece left for one month in an outdoor environment in the summer (specifically, under a roof that is not exposed to rain and in an environment that is exposed to direct sunlight only for a specific time during the day) Was measured. Finally, the difference ΔL * between the L * value measured after standing and the L * value measured immediately after vulcanization is calculated and converted to a relative ΔL * value when ΔL * of Comparative Example 1 is set to 100. And the degree of discoloration. Table 1 shows the results. The smaller the numerical value of the degree of discoloration, the better the discoloration resistance, and the more excellent the black gloss over time.

As is clear from Table 1, the rubber composition containing carnauba wax and the grass of the family Poaceae has the same ozone resistance and the discoloration resistance as compared with the conventional rubber composition containing petroleum wax. Turned out to be excellent.
Furthermore, when a rubber composition was produced using only deoxidized carnauba wax without using rice bran wax, and the same test was conducted, as shown in Table 1, the results were worse than those using petroleum wax. Was.

  The black polymer composition containing the black brightener according to the present invention is superior in black gloss over time and has the same ozone resistance as the black polymer composition containing the conventionally used petroleum wax. It is about. This black brightening agent can be widely used for black polymer compositions for construction, home appliances, tires, and other uses.

Claims (8)

A black brightening agent which contains carnauba wax and grass of the grass family and is used by being blended with the black polymer composition to improve black gloss in the black polymer composition .   The black brightening agent according to claim 1, wherein the weight ratio of the carnauba wax to the grass wax is 80:20 to 40:60.   The black brightening agent according to claim 1, wherein the carnauba wax is a deoxidized carnauba wax.   The blackening agent according to claim 3, wherein the deoxidized carnauba wax is obtained by heating and melting carnauba wax as a raw material in a nitrogen gas atmosphere, and adding and reacting p-toluenesulfonic acid as a catalyst.   The blackening agent according to claim 1, wherein the carnauba wax is untreated carnauba wax.   The blackening agent according to any one of claims 1 to 5, wherein the grass wax is a non-hydrogenated grass wax.   The blackening agent according to any one of claims 1 to 5, wherein the grass wax is a hydrogenated grass wax.   The blackening agent according to any one of claims 1 to 7, wherein the grass wax is rice bran wax.