JP6209649B1 - Filler for rubber compound - Google Patents

Abstract

[Problem] To provide an inexpensive rubber compounding filler having a rubber reinforcing property equivalent to or higher than that of a conventional product (light calcium carbonate). The present invention relates to a novel filler for rubber compound containing one or more selected from calcium oxide and calcium sulfate having a rubber reinforcing effect equal to or higher than that of conventional products. [Selection figure] None

Description

  The present invention relates to a rubber compounding filler having a rubber reinforcing property equivalent to or higher than that of a conventional product (light calcium carbonate) and inexpensive.

  Carbon black, silica, calcium carbonate, and the like are used as fillers for rubber compounds. However, there is a demand for fillers that not only improve the performance of rubber but also reduce costs.

Patent Document 1 discloses a filler for a rubber compound using granulated ash obtained from the following steps.
(1) An industrial waste mainly composed of sludge, waste oil, plastic waste, and paint residue and coal are mixed and fired at a ratio of 2: 1 to obtain fired ash recovered by a bag filter.
(2) The fired ash is classified to 40 μm or less.
(3) The obtained classified ash is granulated to an average particle size of 500 μm.

  In the technology described in Patent Document 1, the compound form of combustion ash is not disclosed, but the main components are a silicon compound and an aluminum compound, and the reinforcing effect of the rubber compound by the obtained filler for rubber compound is not so much obtained. I couldn't.

  Patent Document 2 discloses a rubber filler using classified ash (16 μm) or ground ash (2.4 μm) obtained from coal ash.

  In the technique described in Patent Document 2, only coal ash is used, and the reinforcing effect of the rubber compound by the classified coal ash (average particle size 16 μm) was not obtained so much. Even when coal ash was pulverized to an average particle size of 2.4 μm, the hardness was improved only by 6 points compared to light calcium carbonate.

JP-A-4-55444 JP 59-189144

  An object of the present invention is to provide an inexpensive rubber compounding filler having a rubber reinforcing property equal to or higher than that of calcium carbonate widely used as a filler for rubber compounding. Furthermore, the present invention provides a rubber compound filler that contributes to reducing the use of natural resources and extending the life of the final disposal site by using waste or its combustion products as the main component of the rubber compound filler. The purpose is to provide.

  In order to solve the above problems, the present inventor has found that the calcium oxide and calcium sulfate have a rubber reinforcing property equivalent to or higher than that of the conventional product (light calcium carbonate). Furthermore, it discovered that a waste material and its combustion material could be utilized as a raw material containing a calcium oxide and calcium sulfate, and came to complete this invention.

That is, the filler for rubber compound of the present invention is characterized by containing calcium sulfate contained in the burned product of waste and the hydrated water removed product of waste.

The calcium sulfate is an anhydrous calcium sulfate .

  The wastes include wastewater treatment sludge, papermaking sludge, rubber scrap, shells, eggshells, animal bones, fish bones, flue gas desulfurization gypsum, waste gypsum, municipal waste, paper diapers, wood scraps, bamboo scraps, rice husks, coffee gruel, waste It includes one or more selected from fungal bed, palm shell, food residue, corn cob, and their dehydrated product or hydrolyzed product.

  The fired product is preferably ash obtained from an incineration facility selected from a fluidized bed furnace, a fluidized bed furnace, a stalker furnace, a gasification melting furnace, a rotary kiln furnace, and a fixed bed furnace, and fluidized bed boiler dust Is particularly preferred.

  ADVANTAGE OF THE INVENTION According to this invention, the filler for rubber compounds which has the reinforcement property of the rubber | gum equal to or more than a conventional product (light calcium carbonate) can be provided. Moreover, since the waste or the fired product thereof is used as the calcium oxide and calcium sulfate contained in the filler for rubber compound of the present application, the filler for rubber compound can be provided at low cost. Thereby, it can contribute to reduction of the amount of natural resources used and life extension of the final disposal site.

Diagram showing XRD results for boiler dust A and boiler dust B

[Comparison of effects of calcium oxide, calcium sulfate anhydride and light calcium carbonate on rubber reinforcement (hardness)]
Preparation method of rubber compound Using the compounding ratio shown in Table 1, the mixture was kneaded with a roll, placed in a mold and vulcanized at 160 ° C to prepare a rubber compound.

(Examples 1 to 4)
In the preparation of a rubber compound, Comparative Example 1 was a rubber compound using a conventional light calcium carbonate as a filler for a rubber compound. Similarly, rubber compounds using calcium oxide, calcium sulfate anhydride and calcium sulfate hydrate were designated as Examples 1 to 4.

  The hardness of the obtained rubber compound was measured with a hardness meter, and the results are shown in Table 1.

  As shown in Table 1, calcium oxide and calcium sulfate had a higher rubber reinforcing effect than the conventional product (light calcium carbonate) (Examples 1 and 2). The effect of calcium sulfate hemihydrate was comparable to that of the conventional product (Example 3).

[Analysis of boiler dust]
The ash obtained by burning tires, papermaking sludge and bark was classified with a cyclone. The obtained fine powder was further classified with a sieve, and a 74 μm pass product (average particle size 19 μm: analysis by SALD-2000J (manufactured by Shimadzu Corporation)) was designated as boiler dust A.

  The ash obtained from burning wood waste and coal was classified with a cyclone. The obtained fine powder was further classified with a sieve, and a 74 μm pass product (average particle size 21 μm: analysis by SALD-2000J (manufactured by Shimadzu Corporation)) was designated as boiler dust B.

  The components of boiler dust A and boiler dust B were analyzed using a fluorescent X-ray analyzer EDX-800HS (manufactured by Shimadzu Corporation).

  The calcium contents of boiler dust A and boiler dust B were 46.0% and 11.2% in terms of CaO, respectively.

  The results of XRD analysis of boiler dust A and boiler dust B using a high-power X-ray diffraction apparatus RINT-TTR (manufactured by Rigaku) are shown in FIG. As shown in FIG. 1, boiler dust A contained calcium oxide and calcium sulfate anhydride. Boiler soot B contained calcium sulfate anhydride but did not contain calcium oxide.

[Comparison of effects of boiler dust A and boiler dust B on rubber reinforcement (hardness)]
Rubber compound preparation method A rubber compound was prepared by kneading with a roll using the compounding ratio shown in Table 2, placing in a mold and vulcanizing at 160 ° C.

(Examples 5 and 6)
In the preparation of a rubber compound, Comparative Example 1 was a rubber compound using a conventional light calcium carbonate as a filler for a rubber compound. Similarly, rubber blends using boiler dust A and boiler dust B were designated as Examples 5 and 6.

  The hardness of the obtained rubber compound was measured with a hardness meter, and the results are shown in Table 2.

As is clear from the above results, the rubber compound containing boiler dust A as a filler had higher hardness than the conventional product. Further, the hardness of the rubber compounded with the boiler dust B was about the same as that of the conventional product.
This is because the amount of calcium oxide contained in boiler dust A is larger than the amount of calcium oxide contained in boiler dust B.

  Here, the filler for the blend may be surface-modified for the following purposes and methods. Even when these modifications are carried out, if the components of the filler are the same as described above, they may fall within the scope of the rights of the present invention.

  In other words, the purpose of surface modification is to prevent secondary aggregation, improve wettability with the matrix, provide different functionalities, mask trace amounts of harmful elements, reduce oil absorption, and mechanical strength of the compound Examples include water resistance, oil resistance, weather resistance, chemical resistance, surface gloss improvement, crystal grain growth inhibition, pH adjustment, metal powder oxidation prevention, fluidity improvement, and filler surface protection.

  Surface modification methods include coating modification using fatty acids, waxes, nonionic surfactants, etc., and topochemical modification using silane, titanate, and phosphate coupling agents. , Mechanochemical modification such as acceleration of reaction on unreacted surface by crushing / grinding, modification by encapsulation by mechanofusion method, impact method in high-speed air current, corona discharge, high frequency discharge, glow discharge plasma Examples include modification by high energy used, and modification by precipitation reaction in which water-soluble aluminum salt, silicate, titanium salt or the like is added and neutralized.

  As described above, according to the present invention, it is possible to use a filler for a rubber compound characterized by including one or more selected from calcium oxide and calcium sulfate. In addition, as a filler for the rubber compound of the present application, waste or a fired product of the waste can be used. This makes it possible to provide a rubber compound filler at a low cost, and further contributes to reducing the amount of natural resources used and extending the life of the final disposal site.

a1 and a2: main peak of calcium sulfate anhydride b1: main peak of CaO

Claims (5)

A filler for a rubber compound , comprising calcium sulfate contained in a burned product of waste and a hydrated water removal product of waste. The filler for rubber compounds according to claim 1 , wherein the calcium sulfate is calcium sulfate anhydride.   The wastes are wastewater treatment sludge, paper sludge, rubber scrap, shells, eggshells, animal bones, fish bones, flue gas desulfurization gypsum, waste gypsum, municipal waste, paper diapers, wood scraps, bamboo scraps, rice husks, coffee husks, waste The filler for rubber compounds according to claim 1, comprising one or more selected from fungus bed, palm shell, food residue, corn cob, and their dehydrated product or hydrolyzed product.   The baked product is ash obtained in an incineration facility selected from a fluidized bed furnace, a fluidized bed furnace, a stalker furnace, a gasification melting furnace, a rotary kiln furnace, and a fixed bed furnace. The filler for rubber compounds described in 1. The filler for a rubber compound according to claim 4 , wherein the ash obtained in the incineration facility is dusted with a fluidized bed boiler.