JPS6140343A - Production of powdery rubber - Google Patents

Abstract

PURPOSE:To produce a powdery rubber for pressure-sensitive adhesive, usable without restriction of pot-life, harmless to the human body, and having excellent adhesivity, economically and efficiently, simply by adding a plasticizer and/or a softener to a powdery rubber before use without using a kneader. CONSTITUTION:The objective powdery rubber for pressure-sensitive adhesive can be prepared by mixing (A) 100pts.(wt.) of a powdery rubber having a particle diameter of preferably <=3mm. and prepared e.g. by crushing or pulverizing bale or chip rubber with (B) 20-250pts., preferably 50-100pts. of a plasticizer (e.g. dimethyl phthalate, diisodecyl adipate, etc.) and/or a softener (e.g. paraffin oil, naphthene oil, etc.) before use, by hand with a bamboo spatula or in a vessel furnished with rotary blades.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing powdered rubber for adhesives. In detail, Yuko's rubber-based elastic adhesive, which is a powder rubber method that uses recently developed powdered rubber to create a rubber-based elastic adhesive and can be used on adherends, has great shock absorption, Due to its large deformability or ability to recover from large deformations, it is used in civil engineering, architecture, woodworking, automobiles,
It is usefully used as an adhesive sealant, liquid gasket, or adhesive in a wide range of fields such as aircraft, household goods, and electrical equipment.

[Conventional technology]

There are two types of rubber-based elastic adhesives: a solvent-free type and a droplet type.

The former is a kneaded Silor, Banbury mixer, etc., which adds carbon black, calcium carbonate, plasticizers, softeners, thickeners, anti-aging agents, rubber vulcanizing agents, and rubber vulcanizers to conventional bale-shaped or chip-shaped rubber. It is mixed with rubber compounding agents such as sulfur accelerators and used as is in the market. However, with solvent-free rubber-based elastic adhesives, large amounts of plasticizers, softeners, thickeners, tackifiers, etc. are added to give adhesiveness to the mixed wires. Kneaded Shirole,
It adheres to the chamber walls of Banbury mixers, making wiring work difficult. This contaminant is transported to the construction site in the market in the form of a sheet or in a container, but in the case of a contaminant sheet, during transportation, the sheets or the sheet and the conveyor stick together, making construction work at the site difficult. . For this reason, use something that does not stick to the interfering material, such as release paper.

It has the disadvantage of being packaged and transported in polyethylene sheets, etc. In addition, rubber-based elastic adhesives for natural vulcanization or heat vulcanization are mixed with a rubber vulcanizing agent and/or a rubber vulcanization accelerator in a multi-mixing process, but in general, rubber compounding agents are added and mixed. When kneading with a Shiroll, Banbury mixer, etc., the kneading material generates heat because it is performed under high shear, and if a rubber vulcanizing agent and/or rubber vulcanization accelerator is added. However, there are disadvantages such as a crosslinking reaction starts during kneading or after cross-mixing, which limits the pot life of the adhesive before it can be applied on the market. In order to avoid this limitation on pot life, for example, as a method to suppress the crosslinking reaction of the adhesive obtained by cross-contacting, the adhesive is placed in a freezer immediately after cross-contact, cooled, and transported to the construction site. The extremely uneconomical method of thawing and using a large amount is being used.

The latter is made by kneading the rubber compounding agent using the above-mentioned Kneading Silor, Banbury mixer, etc., then dissolving the mixture in an organic solvent over several hours, putting it in a container, shipping it to the market, and dissolving it at the construction site. It is used. However, solvent-based rubber-based elastic adhesives contain organic solvents and are therefore harmful to the human body, pose a risk of ignition and explosion, and have the disadvantages of being restricted in their manufacture, storage, and use.

Furthermore, in order to produce solvent-free and solvent-based rubber elastic adhesives, in order to knead rubber compounding agents into the conventional veil-shaped or chip-shaped rubber mentioned above, kneading rolls and Banbury mixers are used. In addition, in the case of a solvent type, a dissolution tank is required because the contaminant is dissolved in an organic solvent, and this method cannot be said to be economical in terms of manufacturing equipment costs and manufacturing costs.

[Problem that the invention seeks to solve]

The purpose of the present invention is to simplify the conventional method of obtaining rubber-based elastic adhesives from bale-shaped rubber or chip-shaped rubber, which has many problems, by using recently developed powdered rubber. This is a more economical and efficient method.

[Means for solving problems]

The present invention provides powder for rubber-based elastic pressure-sensitive adhesives that has excellent adhesive strength by simply adding a plasticizer and/or softener to powdered rubber and stirring without using a mixing device such as a mixing roll or a Banbury mixer. This method is advantageous to the rubber manufacturing method, and this method can be used in the field where rubber-based elastic adhesives are used, and also solves many of the problems described in the [Prior Art] section. .

This will be explained in detail below.

[Effect]

In the method of the present invention, a plasticizer and/or softener is added to powdered rubber at the time of use, and the mixture is stirred manually using a bamboo spatula, stick, etc., or in a container with rotary blades to create a solvent-free rubber-based elastic adhesive. It is characterized in that it is used for adhesives and is used for adherends.

Stirring in the present invention refers to stirring in a container or on a table, for example, by the method described above.

For example, if powdered rubber 10009 with a particle size of In the method of kneading using a kneading roll, the roll adhesion of the mixed material is severe, making rolling work extremely difficult, and kneading takes more than 30 minutes.In the present invention, a plasticizer and/or softener is added to the powdered rubber. There is no limit to the weight of the adhesive added and stirred, but if it is done manually with a bamboo spatula or two sticks, it is preferable to do so within 5 hours, and if the weight of the adhesive obtained exceeds 5 kII. Stirring is difficult and puts a strain on the human body.

The powdered rubber used in the present invention 11 is not particularly limited, and powdered rubbers include natural rubber, polychloroprene rubber, acrylonitrile-butadiene/copolymer rubber, ethylene-propylene copolymer rubber, polyacrylate rubber, Chlorosulfonated polyethylene, inbutylene-isoprene copolymer rubber, polyisoprene rubber, polybutadiene rubber.

Examples include powdered rubbers such as styrene-butadiene copolymer rubber and styrene-isoprene copolymer rubber.

The manufacturing methods for these powdered rubbers include pulverizing and crushing rubber in the form of bales or chips, physical means such as spray drying, flash drying, and freezing of rubber latex, or solidifying rubber latex. Chemical methods such as coprecipitation, microcapsule method or polymer ion complex method can be mentioned. 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 manufacturing these powdered rubbers is the method for manufacturing powdered rubber disclosed in JP-A-55-73244. The manufacturing method is to mix an anionic or nonionic rubber latex with an anionic water-soluble polymer, and then use a cationic polymer that can cause a reaction with the anionic water-soluble polymer and a cationic surfactant. It is a powdered rubber obtained by mixing agents, etc., separating rubber particles from rubber latex, adding and mixing a synthetic resin emerald, and dehydrating and drying.

The particle size of the powdered rubber used in the present invention is preferably 5 va or less, and if the particle size exceeds 5 mm, it takes a long time to stir to obtain the adhesive by adding a plasticizer and/or softener to the powdered rubber and stirring. It is time consuming and undesirable.

The plasticizer and/or softener may be any compound that is generally used as a plasticizer or softener for rubber by mixing it with rubber in a kneading machine, a Banbury mixer, or the like.

Examples of plasticizers include heptatarate, dibasic acid ester, glycol ester, epoxy plasticizer, phosphoric acid ester, etc., such as dimethyl heptatarate and diethyl heptatarate.

Di-n-butyl phthalate, diisobutyl phthalate,
Diheptyl 7-thaletate, di-n-octyl 7-thaletate,
Diisooctyl hepthalate, di(2-ethylhexyl) phthalate, dinonyl phthalate, diinodecyl phthalate, ditridecyl phthalate, diacryl phthalate, dicyclodecyl heptalate, di(2-ethylhexyl)adipate, diisodecyl adipate, di(2-ethylhexyl)adipate
-ethylhexyl) azelate, dibutyl sebacate,
Di(2-ethylhexyl) isosebacate.

Diethylene glycol dipenzoate, triethylene glycol di(2-ethylhexoate).

Butyl stearate, butyl oleate, methyl acetyl lyslate, tetrahydrolyl 7-lyl oleate,
Butyl epoxy stearate, octyl epoxy stearate, triphenyl phosphate, cresyl diphenyl phosphate.

Examples include tricresyl phosphate.

Softeners are also mineral oil-based softeners, vegetable oil-based softeners, etc., such as paraffin oil.

naphthenic oil, aromatic oil, castor oil.

Cottonseed oil, linseed oil, rapeseed oil, soybean oil, coconut oil.

Examples include peanut oil. and these plasticizers and/or
Alternatively, the softener can be added in an amount of 20 to 250 parts by weight, preferably 50 to 100 parts by weight per 100 parts by weight of powdered rubber. 20
If the amount is less than 1 part by weight, no adhesive can be obtained even if stirring is performed.

If more than 250 parts by weight is added, the viscosity of the resulting adhesive will be low, the workability will be poor, and the industrial effect will be small.

In the present invention, the adhesive can be obtained simply by stirring the powdered rubber and the plasticizer and/or softener, but when the adhesive is further adhered to the adherend and then subjected to natural vulcanization or heat vulcanization, Effective amounts of known rubber vulcanizing agents and/or rubber vulcanization accelerators can be used. Vulcanizing agents for rubber include sulfur, sulfur compounds, inorganic vulcanizing agents, and oximes.

Nitrono compounds, polyamines, organic peroxides.

Examples include resin vulcanizing agents and isocyanate compounds.

Vulcanization accelerators for rubber include guanidine type, aldehyde-ammonia type, and aldehyde-amine type.

Thiazole type, sul7enamide type, thiourea type.

Examples include thiuram type, dithiocarbamate type, xanthate threads and other known rubber vulcanization accelerators. These rubber vulcanizing agents and/or rubber vulcanization accelerators can be used alone or in combination. The method of use is to blend the powdered rubber with a powder mixer or the like before stirring the powdered rubber and the plasticizer and/or softener, or to use it by mixing and dispersing it in the plasticizer and/or softener. Alternatively, a plasticizer and/or softener may be added to the powdered rubber before stirring, or while stirring. According to the method of the present invention, the rubber-based elastic adhesive can be easily obtained at the construction site, so it is possible to easily obtain the rubber-based elastic adhesive at the construction site. It is not subject to the fateful pot life limit.

An adhesive sealing material that uses a rubber-based elastic adhesive obtained by the method of the present invention and has extremely strong adhesive properties.

When used as a sticky liquid gasket or adhesive, it must be used within a few days after obtaining the adhesive. It preferably exhibits strong adhesion within a few hours of use. If the adhesive is left for more than a few days, its adhesive strength will decrease. By leaving the powder rubber adhesive of the present invention to stand, it is possible to use it as a non-adhesive sealant or a non-adhesive liquid gasket. In addition, known rubber compounding agents such as carbon black, anti-aging agents, tackifiers, tackifiers, calcium carbonate, clay, talc, foaming agents, etc. may be blended with powdered rubber using a powder mixer or the like. Alternatively, it may be mixed and dispersed in a plasticizer and/or softener and used as appropriate.

〔Effect of the invention〕

As is clear from the above explanation, it is economically advantageous to obtain a rubber-based elastic adhesive because it does not involve a cross-mixing process or a dissolution process in an organic solvent. It can be obtained wherever needed, and furthermore, it is not limited by the pot life, which is the fate of naturally vulcanized or heat vulcanized rubber-based elastic adhesives obtained from rubber in the form of bales or chips. In addition, the obtained rubber-based elastic adhesive is solvent-free, harmless to the human body, and poses no risk of ignition or explosion. There are no restrictions on transportation, storage, construction, etc., and it has great industrial and economical advantages.

〔Example〕

The present invention will be explained below with reference to Examples, but it is not limited to these Examples.

The powdered rubber used in the examples was disclosed in Japanese Patent Application Laid-Open No. 53-73.
It was made according to the recipe No. 244. Moreover, all parts are parts by weight.

Examples 1 and 2 and Comparative Example 1 Polychloroprene rubber (hereinafter abbreviated as PCR) latex (trade name [Skyprene G-40SJ latex, manufactured by Toyo Soda Kogyo ■) was adjusted to have a dry weight of 55. Add 20 parts of this rubber latex to 2 parts of sodium alginate.
20 parts of acetic acid aqueous solution was added thereto, and then 10 parts of acetic acid aqueous solution was added to adjust the pH to '45.

This mixed solution was added to 200 parts of a 100% aqueous solution of polyoxyethylene tallow alkylpropylene diamine. Next, after washing the rubber separated into fine powder by decantation, polystyrene emulsion is added to the aqueous solution in which the rubber is dispersed in fine powder at a concentration of 6% by weight based on the dry weight of the rubber latex and mixed. Then, dehydrate and dry to reduce the particle size to 0.
．． A powder FOR of 5 was obtained.

Next, the obtained powdered PCB was placed in a 34-sized polyethylene container, 100 parts of the powdered FOR and 70 parts of diisobutyl phthalate prepared separately were added thereto, stirred manually using a stainless steel spatula, and rubber-based An elastic adhesive was obtained. Table 1 shows the time required for stirring as Example 1. Table 1
Example 2 followed the method of Example 1 except that diisobutyl 7-thalerate in Example 1 was replaced with naphthenic oil (manufactured by Mitsubishi Oil Corporation, trade name: "Mitsubishi 20 Light Process Oil").

Comparative Example 1 is the powder FOR obtained in Example 1 manufactured by Toyo Seiki ■8.
The mixture was wound around an inch roll, 100 parts of the powder POR and 70 parts of ab diisobutyl phthalate were added thereto, and kneaded to obtain a rubber-based elastic adhesive.

At that time, the roll of the cross-conductor adhered strongly, making it difficult to roll. As seen in Table 1, it can be seen that according to the method of using the powder shim of the present invention in Example 1.2, an adhesive can be obtained in an extremely short time compared to the roll kneading method of Comparative Example 1.

Example 3 and Comparative Example 2 100 parts of the powder FOR obtained in Example 1, 4 parts of magnesium oxide, and 5 parts of zinc oxide were mixed in a powder mixer, the mixture was placed in a polyethylene container of 31, and the powder PC
! 15 parts of tris(A-phenylisocyanate) thiophosphate and 65 parts of di(2-ethylhexyl) adipate were added to 100 parts of R and stirred for 3 minutes using a stainless steel spatula to obtain an adhesive.

Next, in order to determine the adhesive strength of the obtained adhesive to the adherend, a wood tensile shear adhesive strength test was conducted using Jl8K 685.
It was carried out according to 1.

First, use a spatula to apply adhesive to the straight-grained makanba board to a thickness of 3H, then place the unapplied straight-grained makamba board to the coated surface, and press it to α2 kg/cm” at room temperature. After 10 minutes of pressure removal, in order to naturally vulcanize the adhesive,
It was left for 7 days at a temperature of 25°C and a humidity of 55°C. Thereafter, the wood tensile shear adhesive strength was measured at a tensile speed of 25 wa/min.

The measurement results are shown in Table 2 as Example 5.

Comparative Example 2 was obtained by roll kneading the powder FOR obtained in Example 1 using an 8-inch roll and the adhesive formulation of Example 5. Next, the tensile shear adhesive strength of the wood was tested in the same manner as in Example 3. Table 2 shows that Example 3 exhibits higher shear adhesive strength than Comparative Example 2.

This is due to the fact that in the roll kneading process of Comparative Example 2, the mixed wire generated heat, and the crosslinking reaction by tris(A-phenylinocyanate) thiophosphate, which is a natural vulcanizing agent for rubber, progressed, resulting in the adhesive strength of the resulting adhesive. This is considered to have decreased.

Example 4.5 and Comparative Example 3 Styrene-butadiene copolymer rubber (hereinafter abbreviated as SBR) latex (trade name: rsRO5, 61 parts manufactured by Nippon Synthetic Rubber) was adjusted to have a dry weight of 35 inches. , Powder SBR with a particle size of 0.2 was prepared in the same manner as in Example 1.
I got it.

Next, 100 parts of this powder 5BR was added to the anti-aging agent P-(p
-) luene sulfonylamide) - 2 parts of diphenylamine, 5 parts of carbon black (manufactured by Tokai Electrode ■, trade name "Sheath" HJ), and 2 parts of powdered sulfur are blended in a powder mixer, and the mixture is placed in a 5AI polyethylene container. 2 parts of sodium di-n-butyl dithiocarbamate, which is a dithiocarbamate-based vulcanization accelerator, and 80 parts of dicyclohexyl phthalate as a plasticizer were added to 100 parts of the powder 8BR, and using a stainless steel spatula, The mixture was stirred manually to obtain an adhesive.

Table 1 shows the time required for stirring as Example 4.

Example 5 is 1+1^-Ch44- in which the dicyclohexyl phthalate of Example 4 is replaced with a 7-tene-based oil (manufactured by Nippon Oil ■, trade name "Comolex No. 2" Flocell oil).
Comparative Example 3 was obtained by kneading the adhesive formulation of Example 4 with an 8-inch roll using the powdered SBR obtained in Example 4. When cyclohexyl 7-talate was added during the crosstalk, the rubber did not wrap around the roll, making it extremely difficult to wind the rubber around the roll. On the other hand, it can be seen that in Example 4.5 in Table 1, the adhesive can be obtained in a much shorter time than in Comparative Example 3.

Procedural amendment- October 5, 1980

Claims (1)

[Claims] 1. Powdered rubber for adhesives, characterized in that (B) a plasticizer and/or softener is added to (A) powdered rubber and stirred at the time of use without being added and kneaded in advance. manufacturing method. 2. The method for producing powdered rubber according to claim 1, wherein (B) a plasticizer and/or softener is contained in an amount of 20 to 250 parts by weight based on 100 parts by weight of (A) powdered rubber.