JP2559932B2 - Manufacturing method of reinforcing filler - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a reinforcing filler.

[0002]

BACKGROUND OF THE INVENTION Fillers are widely used for the purpose of reducing the cost of polymers such as rubber and synthetic resin by increasing the amount and improving the physical properties and processability. Examples of the filler for use include calcium carbonate, basic magnesium carbonate, diatomaceous earth, asbestos, clay, ground stone crushed powder, talc powder, mica powder, cork, cellulose powder, ebonite powder, and reclaimed rubber. You can However,
Since these fillers have a slight lack of affinity with the base material, the reinforcing effect is low.

Therefore, in order to obtain a filler having an excellent reinforcing effect, the size and shape of the filler are changed, or the surface of the filler is treated with an organic substance to be modified. For example, a method of treating the surface of the filler with a modifier such as a silane coupling agent or a phosphoric acid coupling agent is performed. However, depending on the type of inorganic filler, there may be little or no surface modification effect.
This is because when the filler surface is treated with a silane coupling agent, the hydrolyzable alkoxy group of the organosilane compound binds to the particles on the filler surface, while the organic functional group at the other end of the silane molecule is the polymer matrix. This is because the strength can be increased by coupling with the latter, but the latter coupling may be insufficient.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to provide a method for producing a reinforcing filler having an excellent reinforcing effect. .

[0005]

In order to achieve the above object, the gist of the present invention is to provide an alkaline earth metal carbonate, sulfate, sulfite, phosphate, silicate, silicic acid or water thereof. A method for producing a reinforcing filler is characterized in that a particle surface of a Japanese product (hereinafter referred to as "substrate") is treated with an isocyanate compound and then with a polymer having a functional group.

As a method for treating the surface of the substrate with an isocyanate compound, "a semi-dry method in which the substrate powder is sprayed with an isocyanate solution of an appropriate concentration diluted with an organic solvent and treated with stirring," or " A gas phase method in which a substrate and an isocyanate compound are allowed to coexist in an autoclave and heated at 50 to 150 ° C. under reduced pressure with stirring, or “isocyanate compound is added to an organic solvent suspension of the substrate and stirred. However, it is preferable to employ the wet method for uniformly treating and modifying the surface of the substrate particles. Further, in order to improve the treatment efficiency, it is preferable to add a stabilizer (having a catalytic function) such as dibutyltin dilaurate.

The amount of the isocyanate compound added to the substrate depends on the molecular weight of the isocyanate and the size of the specific surface area of the substrate, but is preferably 5 to 20% with respect to the substrate.
If it is 5% or less, the effect of the present invention is low, while if it is added in an amount of 20% or more, the effect of the present invention is saturated and it is not economical.

The amount of the polymer having a functional group added may be an amount capable of reacting with the active reactive group formed on the surface of the substrate by the isocyanate treatment, but usually 5 to 20 with respect to the substrate.
% May be added. Even if the amount added is more than 20%, the plasticizing effect of the unreacted polymer works and adversely affects the reinforcement, which is not preferable.

Examples of the isocyanate compound include ethane diisocyanate, propane diisocyanate, butene diisocyanate of aliphatic diisocyanate, thiodiethyl diisocyanate, dipropyl ether diisocyanate, hexane diisocyanate, 1,3-dimethylbenzoyl diisocyanate of aliphatic diisocyanate having a cyclic group, 1 , 4-diethylbenzoyl diisocyanate,
1,5-dimethylnaphthalene diisocyanate, aromatic diisocyanate 1,3-phenylene diisocyanate, 1,4-
Phenylene diisocyanate, 1-methylbenzol 2,4-
Diisocyanate, 1-methylbenzol 2,6-diisocyanate, 1-methylbenzol 2,5-diisocyanate, 1-
Methyl benzene 3,5-diisocyanate, 1,3-dimethyl benzene 2,4-diisocyanate, 1,3-dimethyl benzene 4,6-diisocyanate, 1,3-dimethyl benzene 2,
Examples thereof include 5-diisocyanate, 1-ethylbenzene 2,4-diisocyanate, naphthalene diisocyanates, biphenyl diisocyanates, di- and triphenylmethane diisocyanates, tri- and tetraisocyanates, and polyisocyanates.

Examples of the polymer having a functional group include a butadiene rubber having a functional group such as a hydroxyl group, a carboxyl group, an epoxy group, an amino group, a mercapto group, an isocyanate group and a halogen element, isoprene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, Chloroprene rubber, polymethylmethacrylate, polystyrene,
Examples thereof include polyoxyethylene. The polymer having a functional group may be appropriately selected from those having a main chain structure suitable for the rubber to which the isocyanate-treated substrate is added and the type of synthetic resin.

[0011]

By the addition polymerization reaction of the adsorbed water consisting of 1 to 5 molecular layers of the filler and the isocyanate, an organic coating having a highly reactive amino group and isocyanate group is formed on the surface of the filler, and a functional group is formed. The terminal functional groups of the polymer containing ## STR1 ## react with the cyanate groups on the surface of the substrate treated with isocyanate one after another to cause a phenomenon such as capturing the matrix polymer with a stapler, resulting in the formation of a strong polymer layer. Strength is improved.

[0012]

EXAMPLES Examples of the present invention will be described below.

(Example 1) 1 kg of hydroxyapatite was suspended in 10 liters of an organic solvent, and 2 g of dibutyltin dilaurate and 10 g of 1-methylbenzene 2,4-diisocyanate were suspended.
0 g was added with stirring to react. Then, 100 g of unend hydroxyl group liquid styrene-butadiene rubber was added with stirring, and after further stirring, the mixture was filtered, washed with an organic solvent, dried and pulverized to obtain a product.

Next, the filler of this Example 1 and Comparative Example 1
(Substrate of Example 1) and Comparative Example 2 (filler obtained by treating the substrate of Example 1 alone with isocyanate) as fillers to 100 parts by weight of a styrene-butadiene block copolymer (styrene content 40% by weight). 40 parts by weight of the above filler was blended, roll-kneaded at 150 ° C., and hot pressed at 150 ° C. to mold. The results of investigation of tensile properties and heat resistance are shown in Table 1 below, and those according to the present invention showed a superior reinforcing effect as compared with Comparative Examples 1 and 2, and the results of viscoelasticity measurement. From the results, it was found that the heat resistance (secondary transition point (temperature) of styrene) according to the present invention was improved.

[0015]

[Table 1]

(Example 2) 1 kg of light calcium carbonate was suspended in 6 liters of an organic solvent, and an organic solvent containing dibutyltin dilaurate and 5,100 g of 1-methylbenzene 2,4-diisocyanate was added with stirring. To react. Next, 100 g of liquid styrene-butadiene rubber having a terminal hydroxyl group was added with stirring, and the stirring was continued, followed by filtration, washing with an organic solvent, drying and pulverization to obtain a product.

Next, the filler of this Example 2 and Comparative Example 3
(Substrate of Example 2) and Comparative Example 4 (filler obtained by independently treating the substrate of Example 2 with isocyanate) as fillers, 100 parts by weight of the filler and 100 parts by weight of the zinc with respect to 100 parts by weight of the styrene-butadiene rubber. 5 parts by weight of flower, 1 part by weight of stearic acid, 2 parts by weight of sulfur and 2.0 parts by weight of vulcanization accelerator were kneaded and vulcanized at 150 ° C. The results of comparing the physical properties of this vulcanized rubber are as shown in Table 2 below, and the one according to the present invention shows an excellent reinforcing effect as compared with the comparative example.

[0018]

[Table 2]

(Example 3) 1 kg of light calcium carbonate was suspended in 2.5 liters of an organic solvent, and 12 g of tributylphenylamine and 120 g of 2,1-methylbenzol 2,4-diisocyanate were added with stirring to react. Let
Next, 120 g of liquid epoxy butadiene rubber having terminal epoxy groups was added with stirring, and the stirring was further continued, followed by filtration.
It was washed with an organic solvent, dried, and then pulverized to obtain a product.

Example 4 10 parts by weight of a polyoxyethylene resin (molecular weight 4000) having amino groups at both ends, 1 to 3 parts by weight of a stabilizer, 1 part by weight of a lubricant, and 100 parts by weight of polyvinyl chloride were used. Zonotolite treated with isocyanate as in Example 1 (specific surface area 26 m ² / g)
0 to 60 parts by weight were blended with a mixer, roll-kneaded on a hot roll at 165 ° C. for 5 to 7 minutes, and a roll sheet was extruded. This roll sheet was pressed at 170 ° C. to obtain a composite. A composite was also obtained by using the same method as in Comparative Example 5 in which zonotolite which had not been subjected to isocyanate treatment was used as a filler. Next, the results of investigating the physical properties of this composite are shown in Table 3 below, and those according to the present invention exhibit excellent reinforcing properties and excellent impact resistance.

[0021]

[Table 3]

[0022]

The filler according to the present invention exhibits an excellent reinforcing effect, and also has excellent heat resistance and impact resistance.

Claims (1)

(57) [Claims] 1. A polymer having a functional group after treating the particle surface of an alkaline earth metal carbonate, sulfate, sulfite, phosphate, silicate, silicic acid or hydrate thereof with an isocyanate compound. For producing a reinforcing filler characterized by treating with