JP2556284B2 - Method for producing chlorinated polyethylene cross-linked composition - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a chlorinated polyethylene-based crosslinked composition.

[0002]

2. Description of the Related Art Chlorinated polyethylene is known as a polymer having excellent mechanical properties, heat resistance, oil resistance, chemical resistance, and weather resistance among various polymer materials by being sufficiently crosslinked. Chlorinated polyethylene produced by a method including a chlorination step at a temperature near the melting point of polyethylene is a material that is drawing attention as an elastomer material. In recent years, in the rubber industry, a continuous cross-linking method using microwave cross-linking (hereinafter referred to as UHF cross-linking) has been actively performed. UHF crosslinking is described in, for example, "Crosslinking Equipment Handbook" (published by Taiseisha Co., Ltd., first edition on March 15, 1983), pages 122 to 134. This cross-linking method uses styrene-butadiene rubber (SBR), ethylene-
Propylene rubber (EPDM) and the like are widely used in the rubber industry, but chlorinated polyethylene rubber is not yet used.

[0003]

The present inventors have actually carried out UHF cross-linking on a known cross-linked composition of chlorinated polyethylene. As a result, the phenomenon that the rubber is foamed after cross-linking, that is, large and small bubbles are present in the rubber There are innumerable phenomena in
It turned out that it cannot be used practically. Therefore, it is an object of the present invention to provide a chlorinated polyethylene composition which suppresses the above foaming phenomenon and has excellent UHF crosslinkability without causing deterioration of other physical properties.

[0004]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventors have found that quick lime or quick lime and an organotin compound are blended with the above chlorinated polyethylene composition for crosslinking. According to the above, it was found that the problem of foaming at the time of UHF cross-linking was solved and excellent cross-linking physical properties were given, and the present invention was completed.

That is, the present invention comprises (a) 100 parts by weight of chlorinated polyethylene and (b) 0.1 mercaptotriazines.
To 5 parts by weight, (C) an amine having a boiling point of 110 ° C. or higher, an organic acid salt of the amine or an adduct thereof, a diarylguanidine, a condensation product of aniline and an aldehyde, and a primary or secondary amine 2-benzo. 0.5 to 3 mol of 1 or 2 or more compounds selected from thiazyl sulfenamide per 1 mol of component (b), (d) 1 to 30 parts by weight of quicklime, (e) organotin compound described later 0.1-
A method for producing a chlorinated polyethylene cross-linked composition, which comprises cross-linking a composition containing 2 parts by weight by microwave.

As the chlorinated polyethylene of the component (a) used in the present invention, chlorinated polyethylene having an arbitrary chlorine content, crystallinity and molecular weight distribution is targeted, and particularly polyethylene having a melt index of 0.01 to 100 is used. Amorphous or substantially amorphous chlorinated chlorine having a chlorine content of 20 to 50% by weight is preferable because the effect of the present invention can be remarkably exhibited.

The mercaptotriazines as the component (b) used in the present invention are represented by the following general formula (I).

[0008]

Embedded image (However, R ³ is selected from the group consisting of a mercapto group, an alkoxy group, an alkylamino group, a dialkylamino group, a cycloalkylamino group, a dicycloalkylamino group, and an arylamino group.)

Specific examples of the above general formula (I) include 1,
3,5-trithiocyanuric acid, 1-methoxy-3,5-
Dimercaptotriazine, 1-hexylamino-3,5
-Dimercaptotriazine, 1-diethylamino-3,
5-dimercaptotriazine, 1-dibutylamino-
Examples thereof include 3,5-dimercaptotriazine, 1-cyclohexylamino-3,5-dimercaptotriazine, 1-phenylamino-3,5-dimercaptotriazine and the like.

The basic amine compound as the component (c) used in the present invention, that is, the amine having a boiling point of 110 ° C. or higher, is particularly an aliphatic or cycloaliphatic group having 5 to 20 carbon atoms. 3 amine with a pk value of about 4.5
The following are good: Typical examples of such amines include n-hexylamine, octylamine, dibutylamine, tributylamine, trioctylamine, di (2
-Ethylhexyl) amine, dicyclohexylamine,
Hexamethylenediamine and the like.

As the organic acid salt or adduct of amine, an amine having a pk value of about 4.5 or less and a pk value of about 2.
Salts or adducts with 0 or more organic acids are preferred. Representative examples of such organic acid salts of amines include n-butylamine acetate, dibutylamine oleate, hexamethylenediamine carbamate, and dicyclohexylamine salt of 2-mercaptobenzothiazole. Examples of diarylguanidine in the basic amine compound include diphenylguanidine and ditolylguanidine. Further, as the condensation product of aniline and aldehyde, aniline and at least one kind of carbon number 1 to 7
The condensation products with aldehydes of are preferred. Specific examples include a condensate of aniline and butyraldehyde, a condensate of aniline and heptaaldehyde, a condensate of aniline and acetaldehyde, and butyraldehyde. Again 1
The secondary or secondary amine 2-benzothiazylsulfenamide is represented by the following general formula (II).

[0012]

Embedded image (However, R ⁴ and R ⁵ may be the same or different and each is a group having 1 to 12 carbon atoms selected from hydrogen, an alkyl group, a cycloalkyl group and an aralkyl group and having no substituent containing a hetero atom. Yes, and R ⁴ and R ⁵ are not both hydrogen)

The primary or secondary amine forming the sulfenamide preferably has a pk value of about 4.5 or less, and specific examples include cyclohexylamine, butylamines, diethylamines, dipropylamines,
Examples include dibutylamines, dihexylamines, dioctylamines, dilaurylamines, dicyclohexylamine, piperidine, pipericone, morpholine and piperazine.

The quicklime as the component (d) used in the present invention is represented by the chemical formula CaO, and is preferably finely pulverized in terms of dispersion of quicklime in rubber and physical properties of crosslinking. Further, a premixed rubber plasticizer may be used to improve dispersibility. As the quicklime used for such a purpose, a trade name “CML # 21” manufactured by Omi Chemical Co., Ltd. is commercially available. The quick lime not only prevents foaming during UHF crosslinking, but also has an action as an acid acceptor during crosslinking, but it is usually advantageous to use in combination with another metal compound that serves as an acid acceptor.

Such an acid acceptor imparts stability to the crosslinked product and an appropriate crosslinking rate, and specifically, the periodic table
Group II metal oxides (excluding CaO), hydroxides, carboxylates, silicates, carbonates, phosphites, borates, oxides of Group IVA metals of the Periodic Table, basic phosphites Examples thereof include salts, basic carbonates, basic carboxylates, basic sulfites and tribasic sulfates. Specific examples include magnesia, magnesium hydroxide, barium hydroxide, magnesium carbonate, barium carbonate, slaked lime, calcium carbonate, calcium silicate, calcium stearate, zinc stearate, calcium phthalate, magnesium phosphite, calcium phosphite, zinc. Hana, tin oxide, litharge, red lead, white lead, dibasic lead phthalate, dibasic lead carbonate, tin stearate, basic lead phosphite, basic tin phosphite, basic lead sulfite, tribasic Lead sulfate etc. can be mentioned.

The blending amount of each of the above components is 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight, and (c) component is based on 100 parts by weight of chlorinated polyethylene (a). 0.5 to 3 mol, and 1 to 30 parts by weight of the component (d) per 1 mol of the component (b). If the amount of the component (d) is less than 1 part by weight, foaming cannot be suppressed, and if it is more than 30 parts by weight, the physical properties after crosslinking are deteriorated. The amount of the metal compound serving as an acid acceptor used in combination with the component (d) is appropriately in the range of 0.5 to 20 parts by weight.

The organotin compound (e) used in the present invention is represented by the following general formula (III). R ₂ SnY or R ₂ SnZ ₂ (III) (wherein R is a C ₁ -C ₂₀ alkyl group, Y is oxygen or C
_{3 to} C ₂₀ aliphatic dicarboxylic acid residue, Z is C _{1 to} C
₂₀ aliphatic carboxylic acid residues , the dicarboxylic acid residue
Groups or the carboxylic acid residues are oxygen atoms of these residues
And Sn atom are bonded by a single bond . Specific examples thereof include di-n-butyltin maleate, di-n-octyltin maleate, di-n-butyltin succinate, and di-n-butyltin oxide. Such organotin compounds are known as stabilizers for polyvinyl chloride, but have not yet been investigated for crosslinked compositions. That is, it is extremely useful to add an anti-scorch agent to the cross-linking composition to prevent premature cross-linking, but when UHF cross-linking as in the present invention is carried out, it seems that this was not considered during normal cross-linking. Since it is exposed to extremely high temperatures, known scorch inhibitors such as organic acids such as phthalic anhydride, N- (cyclohexylthio) -phthalimide, etc. have poor thermal stability and are not effective as scorch inhibitors. Since the present inventors have conducted various studies since various polyvinyl chloride stabilizers are good in terms of thermal stability, as a result, only the above-mentioned organotin compound has a scorch-preventing effect, and the processing stability of the composition is UH
It was discovered that it also has an effect of suppressing foaming during F crosslinking.

The amount of the organic tin compound (e) used in the present invention is 0.1 to 2 with respect to 100 parts by weight of chlorinated polyethylene.
If the amount is less than 0.1 part by weight, the scorch preventing effect, the thermal stability and the foaming preventing effect are not obtained, and if the amount exceeds 2 parts by weight, the crosslinking rate is significantly slowed, which is not preferable.

The compositions used in the present invention include various compounding agents that are commonly used in the art, such as fillers, reinforcing agents, plasticizers, stabilizers, anti-aging agents, lubricants, viscous agents. Addition of additives, pigments, flame retardants, etc. is free.

As a method for mixing the composition used in the present invention, the polymer components may be mixed in advance and the crosslinking component may be mixed therein. Usual mixers such as Hensiel mixer, open roll, kneader and Banbury mixer can be used. When performing such mixing, each component other than mercaptotriazines and quick lime is mixed with chlorinated polyethylene at 150 to 220 ° C, and then mercaptotriazines and quick lime are mixed at 150 ° C or lower, preferably 120 to 50 ° C. Is preferred. When the first-stage mixing is carried out at a temperature lower than 150 ° C., foaming tends to be large, and the cause thereof is not clear, but it is considered that water in the composition is volatilized. Further, if the mixing temperature is higher than 220 ° C., the polymer component may be thermally decomposed. UHF cross-linking of the chlorinated polyethylene composition used in the present invention is described in "Cross-linking Equipment Handbook" No. 122-
The crosslinking method described on page 134 can be used.

[0021]

[Examples] Examples, reference examples and comparative examples are shown below, but all parts and percentages in the compositions are by weight. Reference Examples 1 to 11, Comparative Examples 1 to 4, Examples 1 to 8 Of the compositions shown in Table 1, after polymer components were premixed with a kneader, other components were added and mixed, and the composition was prepared at the end of mixing. The kneader jacket temperature was adjusted so that the product reached 190 ° C., and then mercaptotriazine and quicklime were kneaded with a roll at 70 ° C. for 10 minutes to form a sheet having a thickness of 2 mm.

The chlorinated polyethylene in the composition is a rubbery polymer having a chlorine content of 40% produced by high-temperature chlorination of high density polyethylene having a melt index of 0.8 in an aqueous suspension. The above sheet was extruded by a vent type extruder with a diameter of 4.5 mm into a tube with an inner diameter of 8 mm and an outer diameter of 14 mm at a speed of 3 m / min, and immediately connected to the vent type extruder, having a frequency of 2450 MHZ and a heating section length of 1
After heating the tube temperature to 190 ° C with the UHF heating experimental device of m.
The mixture was placed in a gear oven at 0 ° C. for 5 minutes to perform crosslinking heating.

The expansion ratio was measured as follows. That is, the above-mentioned sheet and the tube after UHF cross-linking are about 2 cm x 2
The sample was cut into cm squares, the specific gravity was measured, and the expansion ratio was calculated by the following formula. Expansion ratio (%) = (1-specific gravity of UHF after crosslinking / specific gravity of sheet) x 100

For crosslinked products having an expansion ratio of 5% or less, J
A tensile test and hardness measurement were performed according to ISK-6301. The results are shown in Table 1. Next, Table 2 shows an example in which an organic tin compound was blended to perform UHF crosslinking, and an example in which this was not blended was compared as a reference example.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

[0029]

[Table 5]

[0030]

[Table 6]

In Table 1 and Reference Examples 1 to 6 and Comparative Examples 1 to 3, it can be seen that the addition of quicklime significantly reduces the foaming ratio regardless of the type of acid acceptor. . In Comparative Example 4, the addition amount of quicklime was 30
It can be seen that when the amount is more than the weight part, the physical properties are deteriorated. In Table 2, Examples 1 to 8 and Reference Examples 7 to 11, it can be seen that the scorch preventing effect is sufficiently exhibited and the foaming ratio is reduced by further blending the organotin compound. In Reference Examples 7 to 9, the scorch preventing effect was not observed and Reference Example 1
When it is 0, neither the scorch preventing effect nor the expansion ratio reduction is sufficient.
In Reference Example 11, a known anti-scorch agent was added, which has an anti-scorch effect but does not sufficiently reduce the expansion ratio.

[0032]

According to the present invention, by adding an appropriate amount of quicklime to the conventional chlorinated polyethylene crosslinking component, U
It becomes possible to significantly suppress the foaming phenomenon at the time of HF cross-linking, and by adding an organic tin compound, scorch can be prevented and obtained. Therefore, excellent cross-linking physical properties and high continuous productivity can be maintained by the UHF cross-linking method.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08K 5/31 KEZ C08K 5/31 KEZ 5/37 KFE 5/37 KFE 5/47 KFJ 5/47 KFJ 5/57 KFR 5/57 KFR // (C08L 23/28 61:22)

Claims (1)

(57) [Claims] 1. (a) Chlorinated polyethylene
100 parts by weight (b) Mercaptotriazines 0.1 to 5 parts by weight (C) Amines having a boiling point of 110 ° C. or higher, organic acid salts of the amines, or adducts thereof, diarylguanidines, condensation products of aniline and aldehydes Component and one or more compounds selected from 2-benzothiazylsulfenamide of primary or secondary amine (b) component 1
0.5 to 3 mol per mol (d) quicklime 1 to 30 parts by weight (e) 0.1 to ₂ parts by weight of an organotin compound represented by the following general formula R ₂ SnY or R ₂ SnZ ₂ (where R is A C ₁ -C ₂₀ alkyl group, Y is oxygen or C
_{3 to} C ₂₀ aliphatic dicarboxylic acid residue, Z is C _{1 to} C
₂₀ aliphatic carboxylic acid residues , the dicarboxylic acid residue
Groups or the carboxylic acid residues are oxygen atoms of these residues
And Sn atom are bonded by a single bond. A method for producing a chlorinated polyethylene-based cross-linked composition, which comprises cross-linking a composition containing a) by microwaves.