JPS6230110A - Cold-setting type elastic material composition - Google Patents

Abstract

PURPOSE:The titled composition providing an elastic material having extremely improved mechanical properties only by pressure molding, having improved economic efficiency, obtained by blending currently developed powdered rubber with an acrylic ester, an organic peroxide and a promoter for decomposition of the organic peroxide. CONSTITUTION:(A) 100pts.wt. powdered rubber having <=5mm, preferably <=1mm particle diameter is blended with (B) 0.1-50pts.wt. acrylic ester (e.g., methyl methacrylate, etc.,), (C) 0.1-30pts.wt. organic peroxide (e.g., acetyl peroxide, etc.,) and (D) 0.01-20pts.wt. promoter (e.g., N,N-dimethylaniline, etc.,) for decomposition of the component C and stirred usually by a powder mixer such as high-speed mixer, etc., to give the aimed composition.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a room temperature curable elastomer composition. More specifically, the present invention relates to a room temperature curable elastomer composition which has been developed in recent years and is made by adding and blending an acrylic ester, an organic peroxide, and an organic peroxide decomposition accelerator to a powdered rubber.

(Prior art) Rubber elastic bodies made from rubber are generally produced by adding a vulcanizing agent and vulcanizing the rubber to conventional bale-shaped or chip-shaped rubber using a kneading machine such as a kneading roll machine, an internal mixer, a double-arm kneader, etc. Accelerators and other rubber compounding agents are added and kneaded to obtain a rubber kneaded product, and then a pressure molding machine, such as a roll molding machine, an extrusion molding machine, a compression molding vulcanizer, an injection molding vulcanizer, a calender roll. etc., and further pressurized with a vulcanizer such as a vulcanizer, hot air circulation vulcanizer, drum type vulcanizer, fluidized bed vulcanizer, compression mold vulcanizer, injection mold vulcanizer, etc. A method of obtaining a rubber elastic body by heating and curing a molded rubber kneaded product at a high temperature of 100° C. or higher has been adopted. That is, as mentioned above, the conventional method of obtaining a rubber elastic body requires an extremely long and complicated manufacturing process, and always involves a crosstalk machine.

A pressure molding machine and a vulcanizer are required, and rubber mixed
This method is extremely uneconomical in terms of manufacturing costs and energy consumption, as it requires energy to heat and harden at a high temperature of 00° C. or higher.

On the other hand, it is possible to omit the step of heating and curing at high temperatures using a vulcanizer and curing the pressure-molded rubber hybrid material at room temperature. A concrete method for this is the conventional method of adding a room-temperature curing agent to rubber bales or chips in a kneading machine, then press-molding, and curing at room temperature. As heat is generated by the high shear force of the machine, the room temperature curing agent added reacts and hardens during or immediately after the rubber mixture is taken out from the machine. For this reason, subsequent molding using a pressure molding machine is no longer possible, and this method is generally not adopted. There are room-temperature curing agents that do not cause a curing reaction even if the rubber generates heat during kneading. However, when such a curing agent is used, the curing reaction after pressure molding is slow, and it takes several months or more for the pressure molded mixed material to harden at room temperature, so K is 1.
This method is generally not used except in special cases.

For this reason, it is still necessary to adopt the conventional uneconomical method described above, and there is a strong demand for a room-temperature-curing elastomer composition that can omit the heat curing step at high temperatures using a vulcanizer. is the reality.

(Problems to be Solved by the Invention) The present invention resides in a composition that makes it possible to reduce production costs and energy consumption, which are problems when obtaining a rubber elastic body. That is, the present invention provides a room-temperature-curing elastomer composition that uses recently developed powdered rubber and can omit the step of heating and curing a pressure-molded rubber mixture at high temperatures using a conventional vulcanizer. It is.

(Means and effects for solving the problems) Invention 1 This product is made by adding and stirring an acrylic ester, an organic peroxide, and a decomposition accelerator for the organic peroxide to a recently developed powdered rubber.

It exhibits a room temperature curing reaction just by pressure molding with a pressure molding machine,
The present invention is a room temperature curable elastomer composition that can provide an elastomer with extremely excellent mechanical properties.

The present invention will be explained in detail below.

The present invention resides in a composition prepared by adding and stirring an acrylic ester, an organic peroxide, and an organic peroxide decomposition promoter to powdered rubber. In the present invention, the addition and stirring refers to mixing an acrylic ester, an organic peroxide, and an organic peroxide decomposition promoter into powdered rubber, and a commonly used powder mixer is used for the mixing. Examples of powder mixers include ribbon blender dart high-speed mixers, stirring vane mixers, paddle mixers, muller mixers, tumble mixers, and the like. Or a stick in a container.

It is also possible to mix with a bamboo spatula. The mixing temperature is within a range where the powdered rubber does not form agglomerates during mixing.
It is usually carried out at room temperature. Although the mixing time is not limited, it is preferable to mix until the acrylic ester, organic peroxide, and organic peroxide decomposition accelerator are sufficiently dispersed in the powdered rubber. After the obtained cold-curing elastomer composition is molded using the above-mentioned pressure molding machine, it is cured within several hours by simply being left at room temperature, and an elastic body can be obtained. In place of powdered rubber, which is one of the components of the composition of the present invention, when the kneading machine described above is used to obtain rubber in the form of bales, rubber, or chips, acrylic ester, organic peroxide, and organic peroxide are used. It takes a long time to add and knead the decomposition accelerator, and the heat generated by the rubber hardens the rubber during kneading, making it impossible to mold the product using a pressure molding machine.

That is, the ability to obtain the composition of the present invention can only be achieved by using powdered rubbers developed in recent years. Examples include powder combs such as rubber, ethylene propylene copolymer rubber, polyisoprene rubber, chlorosulfonated polyethylene, and polyacrylate rubber. These powdered rubbers can be produced by physical means such as pulverizing or crushing rubber in the form of bales or chips, by spray drying powdered rubber, or by freezing rubber latex, or by coagulating rubber latex, coprecipitation, etc. Chemical methods such as a microcapsule method or a polymer ion complex method may be used.

The present invention can be applied to powdered rubber obtained by any of these methods. These powdered rubbers can be used alone or in combination. An example of the method for producing these powdered rubbers is the method for producing powdered rubber disclosed in JP-A-55-73244. The manufacturing method is to mix anionic or nonionic rubber latex with an anionic water-soluble polymer, and then trap a cationic polymer that can cause coacervation with the anionic water-soluble polymer, a limited ionic surfactant, etc. There is powdered rubber obtained by mixing, separating rubber particles from rubber latex, adding a synthetic resin emulsion, and dehydrating and drying. In the composition of the present invention, the particle size of the powdered rubber is 5111J or less, preferably 2.
Powdered rubber having an IQ or less, more preferably an IQ or less, is applied.

If the particle size exceeds 5 fins, the dispersion of the acrylic acid ester, organic peroxide, and organic peroxide decomposition accelerator into the powdered rubber will be insufficient during mixing with a powder mixer, resulting in poor mechanical strength. An elastic body cannot be obtained.

The acrylic ester referred to in the present invention refers to acrylic ester and/or methacrylic ester, and when these two are collectively called (meth)acrylic ester, it means alkyl (meth)acrylate, (meth)acrylic ester, etc. Acid hydroxyalkyl, glycidyl (meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, tripe gastric pyrene glycol di(meth)acrylate Acrylate, trimethylolpropane tri(meth)acrylate.

tetramethylolmethanetetra(meth)acrylate,
Polyester (meth)acrylate obtained by the reaction of methacrylic acid, glycols, and polybasic acid, epoxy (meth)acrylate obtained by the reaction of epoxy compound and (meth)acrylic acid, and polybasic acid and aminoalfur reacted. amide (meth)acrylate obtained by reacting hydroxyalkyl (meth)acrylate with (meth)acrylic acid; urethane (meth)acrylate obtained by reacting hydroxyalkyl (meth)acrylate with a polyisocyanate compound;
Tetrahydrofurfuryl (meth)acrylate, (meth)
Specific examples include diethylaminoethyl acrylate. These numbers can be used alone or as a mixture.

And powdered rubber using these acrylic esters 10
1 to 50 parts by weight, preferably 5 to 30 parts by weight, and more preferably 10 to 20 parts by weight are mixed per 0 parts by weight.

If the acrylic ester is less than α1 part by weight, the degree of curing of the room temperature curable elastomer composition will be low, and the elastomer will not exhibit sufficient mechanical strength. Even if more than 50 parts by weight is mixed, the mechanical properties of the resulting elastic body do not change and it has no industrial value.

Examples of organic peroxides used in the present invention include ketone peroxide and diacyl peroxide.

oxide, methyl isobutyl ketone peroxide,
Cyclohexanone peroxide, acetyl peroxide, lauryl peroxide.

Benzoyl peroxide, p-cyclobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, isobutyl peroxide, 1-butyl hydroperoxide, cumene hydroperoxide, di-
Isopropylbenzene peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, z5-dimethyl-λ5-di(
Examples include t-butylperoxy)-hexane. These may be used alone or in combination. The amount of organic peroxide in the composition is 11 to 30 parts by weight per 100 parts by weight of the powdered rubber used.

Preferably α5 to 10 parts by weight, more preferably 1 to 5 parts by weight. If cL is less than 1 part by weight, the amount of organic peroxide is so small that the curing reaction of one composition takes a long time and is of no industrial value. Furthermore, if the amount exceeds 30 parts by weight, the composition will harden extremely quickly, and the composition will harden before being molded by pressure molding, making it impossible to obtain a molded elastomer composition.

The organic peroxide decomposition accelerator used in the present invention is a metal complex of tertiary amine and acetylacetone.

Metal salts of naphthenic acids, thiourea compounds, amine-aldehyde condensates, such as N,N-dimethylaniline, N,N-dimethyl-P-)luidine, acetylacetone vanadyl, copper naphthenate.

Cobalt naphthenate, trimethylthiourea, ethylenethiourea, aldol-α-naphthylamine.

Examples include triethylenetetramine. These may be used alone or in combination. The amount of the organic peroxide decomposition accelerator used in the composition of the present invention is per 100 parts by weight of the powdered rubber used! 101 to 30 parts by weight is blended. Preferably it is blended in an amount of 11 to 15 parts by weight, more preferably 0.5 to 5 parts by weight. If the amount of the organic peroxide decomposition accelerator is less than 101 parts by weight, the composition will harden slowly at room temperature, making it impractical. Further, even if the amount exceeds 20 parts by weight, the effect on the curing rate does not change much.

In obtaining the composition of the present invention, known rubber additives such as anti-aging agents, stabilizers, vulcanizing agents, vulcanization accelerators, carbon black, etc., may be added to the extent that they do not impair the characteristics of the present invention. , white filler, softener.

A plasticizer 2, a coloring agent, a chemical agent, and the like are appropriately blended as necessary.

(Effects of the Invention) As is clear from the above explanation, the room-temperature curable elastomer composition of the present invention has excellent mechanical properties and at the same time has rubber elasticity using conventional veil-shaped or chip-shaped rubber as a raw material. It is a composition that can omit the heat curing step using a vulcanizer, which is indispensable in the production of a body, and furthermore, the curing time at room temperature is significantly shortened, and it has extremely excellent characteristics in terms of manufacturing cost and energy consumption.

(Examples) The present invention will be explained below based on the practical side pressure, but the present invention is not limited to these Examples.

In addition, the powdered rubber used in the examples was obtained from Japanese Patent Application No. 53-732.
It was made according to the manufacturing method for powdered rubber No. 44.

All parts are by weight.

Examples 1 to 3 and Comparative Example 1 Table's'c N polychloroprene rubber (hereinafter: pa
(abbreviated as R) latex (product name “Skyplain B −
30'' latex (manufactured by Toyo Soda Kogyo ■) with a particle size of 1 u or less and an average particle size of α5tm. The method for obtaining the composition was as follows. In Example 1, powder FOR was put into a 3 ton stirring vane type mixer, and per 100 parts by weight of powder FOR used, 5 parts of zinc white and 10 parts of carbon black were added. 850 parts by weight and 4 parts by weight of benzoyl peroxide were added for 15 seconds at room temperature.
After rotating the rotor at r, p, and m to mix uniformly,
While rotating the rotary blade, adjust the used powder FO on the other hand.
10 parts by weight of methyl methacrylate per 100 parts by weight of R
72 in the weight department! J > 1 n's flJ
A solution of the three components mixed in an amount of 1 part by weight of tohydroquinone monomethyl ether α was added dropwise over a period of 1 minute, and the mixture was further stirred for 50 seconds to obtain a room temperature curable elastomer composition.

Next, the obtained composition was molded into a sheet for 15 seconds using a Toyo Seiki D'roll molding machine, put into a sheet mold with a thickness of 2U, and heated to a pressure of 150 at 9/-2 room temperature. 20 in
Pressure molding was performed using a minute pressure molding machine. After the obtained molded product was left at room temperature for S hours to harden, a sample was prepared according to J.K. SK 6501 and a tensile test was conducted in order to determine the mechanical properties of the molded product.

Example 2 followed the method of Example 1 except that 10 parts by weight of methyl methacrylate in Example 1 was changed to 20 parts by weight. Example 6 followed the method of Example 1 except that 4 parts by weight of benzoyl peroxide in Example 1 was replaced by 3 parts by weight of cumene hydroperoxide, and 1 part by weight of dimethylaniline was replaced by 2 parts by weight of triethylenetetramine. In Comparative Example 1, the powder FOR in Example 1 was changed to chip FOR (trade name: Skyplane B-50J manufactured by Toyo Soda Kogyo ■), and the chip FOR was wound around an 8" roll forming machine in the same manner as in Example 1. A composition containing 10 parts by weight of methyl methacrylate was obtained by roll kneading.

A solution of 1 part by weight of dimethylaniline and 1 part by weight of hydroquinone monomethyl ether α and ρδ was mixed into the PQR slowly, taking 40 minutes to knead, and the composition had already hardened, probably due to the heat generated by the rubber during the mixing. was progressing, and molding using the pressure molding machine was not possible.

As is clear from Table 1, the molded articles obtained from the compositions of the present invention in Examples 1 to 3 exhibit extremely excellent mechanical properties. This is considered to be because the acrylic ester, organic peroxide, and organic peroxide decomposition accelerator in the composition of the present invention contribute to the curing reaction of powder FOR.

Example 4.5 and Comparative Example 2 Acrylonitrile-butadiene copolymer rubber (hereinafter referred to as NBR)
Table 2 shows the composition of a room-temperature-curing elastomer manufactured using powdered rubber with a particle size of 1υ or less and an average particle size of 0.511 m manufactured from latex (trade name [N1po11561j manufactured by Nippon Zeon ■)] .

The composition was obtained as follows.

In Example 4, powdered NBR was put into a 3OL stirring vane type mixer, and per 100 parts by weight of powdered NBR used, 5 parts by weight of zinc white, 4 parts by weight of benzoyl peroxide, 500 parts by weight of ferrite, and 5 parts by weight of aromatic process oil. of the mixture was added, and the rotary blade was rotated at 800 r, p, m for 30 seconds at room temperature to mix uniformly. Next, while rotating the rotary blade, a solution containing 20 parts by weight of n-butyl acrylate, 11 parts by weight of dimethylaniline tmas, and 11 parts by weight of hydroquinone methyl ether was added to 100 parts by weight of the powdered rubber prepared. The mixture was added dropwise for 1 minute and mixed, and further stirred for 30 seconds to obtain a room temperature curable elastomer composition.

The obtained composition was passed through a 12" roll forming machine manufactured by Nishimura Koki ■ to agglomerate it, and then a sheet having a thickness of αS+U was produced using an inverted L8" calendar roll forming machine manufactured by Nishimura Koki ■. After the obtained sheet was left at room temperature for 24 hours to cure, a tensile test was conducted according to J.K. SK 6501 to determine the mechanical properties of the sheet.

Example 5 followed the same method as Example 4, except that n-butyl acrylate in Example 4 was replaced with methyl methacrylate.

Comparative Example 2 uses alpha cumyl hydroperoxide and cobalt abecenate shown in Formulation A2 of Example 2 of the low-temperature vulcanizable rubber composition of JP-A-49-66734, and a predetermined composition shown in Table 2. The mixture was kneaded using a 12'' roll forming machine, and then formed into a sheet having a thickness of CL 5 m using an inverted L8'' force render roll forming machine. The sheet was left at room temperature for 10 days, and a tensile test was conducted in the same manner as in Example 4.

As is clear from Table 2, it is clear that Example 4.5 has higher tensile strength than Comparative Example 2, and as mentioned above, Example 4.5 was left at room temperature for one day. ,
The time is reduced to 1/10 compared to Comparative Example 2.

Claims (1)

[Claims] (1) Per 100 parts by weight of powdered rubber with a particle size of at least 5 mm, 0.1 to 50 parts by weight of acrylic acid ester, 0.1 to 30 parts by weight of organic peroxide, and 0 parts by weight of organic peroxide decomposition promoter. A cold-curing elastomer composition prepared by adding and stirring .01 to 20 parts by weight.