JPS5945339A - Preparation of rubber composition - Google Patents

Abstract

PURPOSE:To obtain a rubber composition having easy processing properties in a high blend ratio of vinyl chloride resin, having oil resistance and ozone resistance, obtained by adding a vinyl chloride resin into acrylonitrile-conjugated diene copolymer rubber uniformly with making it keep specific particle diameters without melting it. CONSTITUTION:A vinyl chloride resin (preferably having 800-2,000 average polymerization degree) having <=1mu, preferably 0.2mu average particle diameters is dispersed into acrylonitrile-conjugated diene copolymer rubber having 10- 50wt% bonded acrylonitrile uniformly while it keeps the particle diameters without being melted, to give the desired rubber composition. A blending ratio of both components in the composition is in a range of 5-55wt% resin to 95- 45wt% copolymer rubber, and the composition is obtained by latex blend or dry blend at a temperature <= the melting point of the vinyl chloride resin.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an uninventive method for producing a gel-silk composition comprising an acrylonitrile-conjugated diene copolymer rubber and a vinyl chloride resin, and more specifically to the rubber composition. In the process of manufacturing products, the particle form of each vinyl resin is maintained in the acrylonitrile-conjugated diene yarn copolymer rubber without melting (it is characterized by uniformly dispersing it in the shape of a 7-1\\ fp). The present invention relates to a method for producing a rubber composition having oil resistance, ITi, and 1 ozone properties.

Conventionally, acrylonitrile-cyclodiene copolymer rubber (NB
Rubber compositions (hereinafter sometimes referred to as polyblends) comprising R) and vinyl chloride resin (PVA) are widely used.

By the way, in order for a polyblend to exhibit sufficient ozone resistance, NBR (!: PVc) must be mixed sufficiently uniformly and p
It is necessary that VC be completely dissolved in NBR.

For this purpose, when manufacturing borin 1/nd, NBR and p
At the stage of mixing the PVC, or after mixing, the L-bath melted PVC is sufficiently dissolved and dispersed in NBR under shear force at a temperature higher than the temperature at which the PVC melts (usually referred to as the gelling temperature), and the PVC is dissolved and dispersed in the NBR. NBR/I) as particulates or aggregates
It must be ensured that Ve does not remain in the mixture.

If the polyblend was prepared at a temperature lower than the gelling temperature of PVc, mixing would be sufficient even if the vortex temperature was higher than the gelling temperature of PVc.
Ozone-related! In addition, the tensile strength does not reach a sufficient level.1. In this way, a sufficient level of tensile strength and 1l
It is difficult to counterfeit because it is difficult to manufacture a Bollig L/Nd with "lit" properties.

A polyblend prepared by thorough mixing at a temperature lower than the gelation temperature of FPVE (1-1) is added to the polyblend (-) which has a high viscosity as a filler and reinforcement. In addition, the viscosity of the compound becomes extremely high, making it difficult to operate the rubber, causing swelling, scorch, etc. Therefore, it is likely that a polyblend vulcanizate with high hardness can be manufactured by fA, and improvement is desired.

The inventor of the present invention has solved such problems and completed the present invention as a result of the novelty of the vise. It is an object of the present invention to provide a method for producing a rubber composition having strong ozone properties. - When producing a rubber composition consisting of L'l vinyl chloride resin, the vinyl chloride resin having an average particle size of 5μ or less is not melted and the particle size is maintained while it is being mixed with Acrylic IJ O nitrile. - Achieved by uniformly dispersing it in a conjugated diene copolymer.

Except for vulcanizing the polyb1/nd obtained by the method of the present invention at a temperature higher than the gelling temperature of the vinyl chloride resin, the method of the present invention involves the process of producing a polyblend and the use of a polyblend. During the processing process, it is necessary to avoid melting the vinyl chloride resin in a bath (referred to as gluing), and as a result, the viscosity of the resulting polyblend is low, and the viscosity of the blend at high filling levels is also kept low. This improves flow characteristics, such as reducing burning and scorch caused by power consumption and heat generation during the processing process, and making it easier to formulate high-hardness formulations.

The vinyl chloride resin used in the present invention is mixed with acrylonitrile-conjugated diene copolymer rubber in the process of manufacturing the composition, and in the molding process other than vulcanization, without gelation. In order for the composition to have ozone resistance equivalent to that produced by the conventional method of gelling vinyl chloride resin and thoroughly mixing it with NBR, and to improve flowability, the average particle size should preferably be 5μ or less. The thickness must be 1μ or less, more preferably 02μ or less. When the particle size exceeds 5μ, it becomes difficult to dissolve the gelled resin into NBR using only the thermal history during vulcanization, and ozone resistance, strength properties, etc. decrease. 40f
] and more, /! T't +, < trt, 8 []
1. Vinyl chloride-based 4'il resins include tl, -+r vinyl chloride A resin, vinyl chloride-vinyl acetate co-jit9 resin, vinyl chloride-
Ethylene-vinyl acetate copolymerization (lk% i%'J polymerization, emulsion polymerization, bulk polymerization, etc.) However, any manufacturing method may be used as long as it has the above characteristics.

The acrylonitrile-conjugated diene copolymer rubber used in the present invention is composed of acrylonitrile and at least one type of conjugated diene monomer such as 1.5-butadiene, Inglene, and 15-pentadiene (combined with acrylic acid, methane, etc.). It is a multicomponent copolymer made by copolymerizing α, β-ethylenically unsaturated compounds such as acrylic acid and maleic acid, or dicarboxylic acid and esters thereof. Specifically,
Acrylonitrile-butadiene copolymer rubber, acrylonitrile-imprene copolymer rubber, °r IJ ittl
Examples include -IJ/l'l Jeepen-Imprene terpolymer rubber and acrylonitrile-butadiene-butyl-acrylic 1-note terpolymer rubber.

These copolymer rubbers are manufactured by emulsion polymerization, solution polymerization, etc., but there are no restrictions on the manufacturing method itself.

1 part of bound acrylonitrile in the copolymer rubber is usually 10 parts due to the functionality of oil-resistant rubber and compatibility with vinyl chloride resin.
The amount of bound acrylonitrile is within the range of 50% by weight, and a suitable amount of bound acrylonitrile can be determined within the above range depending on the properties required for the rubber-resin mixture.

The mixing ratio of acrylonitrile-conjugated diene copolymer rubber and vinyl chloride resin may be determined as appropriate depending on the purpose of use, but it is usually U, acrylonitrile-conjugated diene copolymer rubber 95-45%. On the other hand, the sound-stopping vinyl resin 5
~55 tons M, 1, uninvented acrylonitrile-
In a composition consisting of a conjugated diene yarn, F polymer, and a vinyl resin, the radius conversion of these polymers is approximately determined by the gelling temperature of the resin (which varies depending on the average polymerization IW). Mixing j2 at a temperature +i lower than (which is around 170C),
The latex blending method involves drying the coprecipitate, and the trial method involves mixing the solid aggregates together in a blender of the same standard as a roll or Banbury at a temperature lower than the gelling temperature of the fat. Produced by blending method etc.7
Unlike the conventional method, the method of the present invention dries at a temperature higher than the melting temperature of the vinyl chloride resin and under a shearing force when drying in the latex blending method! There is no need to carry out step (1), and it is sufficient to use the same drying method (for example, 100 U
In addition, in the Doller f-blend method, there is no need for mixing at fR and Iff above the gelling temperature of the vinyl resin (drying using a hand dryer as described below), and there is no need to mix at fR and Iff above the gelling temperature of the vinyl resin (approximately 100C or less). The rubber can be mechanically mixed well at a temperature of
.

In the rubber composition obtained by the method of the present invention, as mentioned above, the vinyl chloride resin does not gel at all, but is dispersed in the acrylonitrile-conjugated diene rubber while completely maintaining its particle form. There is.

The composition prepared by the production method according to the present invention may contain reinforcing agents such as carbon black, silica, carbonaceous carbon, fillers, etc.
Vulcanizing agents, vulcanization accelerators, OL plasticizers, processing aids, etc. can be mixed and used.

In order for the composition produced by the production method of the present invention to exhibit ozone resistance equivalent to that produced by the conventional method, when producing rubber products using the composition produced by the method of the present invention, it is necessary to The vulcanization may be carried out at a temperature equal to or higher than the gelling temperature of the vinyl chloride resin at Since it also depends on the amount, it is necessary to measure the gelation temperature in advance and set a preferable vulcanization temperature. Is vinyl chloride a normal product? +1 Static and dynamic Onon K (experiments were conducted, and the results are shown in Table 3... Table 2 Mixture recipe (stick (''<1=, combination) N B F,
/P VO mixture 1Ll O@@Tm stearic acid 1=zinc white
5... SRF carbon black 60 〃n
J' VVJ I”Ijl I)O,P
(b) 20
〃Sulfur (1,
5zz Promoting agent TT tfi+ 15 〃Promoting f1 agent (jZ+”1 1.5-・(1) Dioctyl tucrate (5) Detrameburthiuram disulf・f-do(6)
Cyclohegysyl benzothiryl sulfenamide Figure 1 POA t,'<+K Method of the present invention and conventional method-C Preparation, fi, N I), 1(,'i' V
The dispersion state of the C mixture was observed at -f &+'n M K, and the results were % near J\t'f, 'IJ, @'
fYi M 1 OyoiJ Experimental number +46)N J3-
R, / -L' VC mixtures (all prepared by the method of the present invention, with no compounding agents added) and these mixtures were heated to a temperature 1° higher than the gelling temperature of VO (1.
80C) for 5 minutes, freeze each sample, prepare ultra-thin sections using an ultra-microtono, and observe them with a transmission type electron microscope (Figures 1 to 2J). ; The results shown in Figure 4 were obtained.

Similarly [7? :, Figure 6 shows the results when the mixture of Experiment No. 8 (comparative example) was subjected to the above thermal history, and the results of the mixture of Experiment No. 11 (conventional method, without the above thermal history). The results are summarized in Table 4 and are shown in FIG. 5. , PV (: lower gluing temperature I; ('+ I, ff-) vulcanized q) 1 conventional method C) Ino, addition of the composition (hfy product 4'i, -
,,11 comparison (7 is positive) ozone property (f61-extremely inferior-
(However, the gelation temperature of P V l is 7</) Temperature 1
In the river 7J1ro1'f I-,,1? ) Nail on the stand-3
1-Method's Inno-Composition Sword] I'i'('i is the equivalent 1llitd saw/1'l is 1#I).

Example 2 PVO having an average particle size of 1 and an average particle size as listed in Table 6
Using the latex and NBR latex, the ino-composition of the present invention and the control example and the ino-composition of the conventional method of the invention were prepared in the same manner as in Example 1.
NBR/PVC = 70/3D weight 1F), A compounded rubber composition was prepared in the same manner as in Example 1 using the high hardness compounding recipe shown in Table 5, and the compound viscosity was adjusted according to JJS K6301, and the press processing was carried out by 17 OUXiO. Determine the normal physical properties of sulfur, static ozone properties, and the minimum torque of a mesirate disc rheometer (Higashi?-'f = III M Company product). (High hardness combination) NBR/PVO mixture 100 parts Stearic acid 1N Zinc white 5 ・SRF Carbon black 90 〃Plasticizer DOP 20'' Sulfur 0,
5# Accelerator TT 1.5# Accelerator e Z 1.5・2e As is clear from the results in Table 6, the blends produced by the production method of the present invention have a lower blend viscosity than those produced by the conventional method. Low (formulation Mooney viscosity.

MS1+4 (using a small rotor, 100°C) is also characterized by a high formulation viscosity at high temperatures, with a minimum torque of -17 ohm. Low blend viscosity leads to improvements in kneading workability, exothermic properties, and scorch properties, which are problems especially when obtaining high hardness blends, and
This also leads to a reduction in power consumption. Furthermore, the high viscosity of the compound at high temperatures indicates that it is effective in preventing deformation during vulcanization, which is a problem in continuous vulcanization, pot vulcanization, etc. Furthermore, the vulcanizate obtained by vulcanizing the rubber composition of the present invention at a temperature higher than the gelation temperature of PVC has ozone resistance equivalent to that of the vulcanizate of the composition of the conventional method. It is very effective especially when obtaining high hardness compounds with oil resistance and ozone resistance.

[Brief explanation of drawings]

1 to 6 are electron micrographs showing the dispersion state of the NBR/PVO mixture of Example 1. Scale 11- is //J. Patent applicant Zeon Corporation

Claims (1)

[Claims] When producing a GoJ-silk composition consisting of an acrylonitrile-conjugated diene copolymer and a vinyl chloride resin,
If the average particle size is 5 μ or more T (D), the vinyl chloride resin is uniformly dispersed in the acrylonitrile-conjugated diene copolymer while maintaining the particle size of 111 kg 13 without melting. Method for producing a rubber composition having desired oil resistance and ozone resistance 3.