JP2001151898A - Cross-linking agent composition and method for cross- linking by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cross-linking agent composition capable of suppressing the scattering of a powder when mixing the cross-linking agent with a rubber or a thermoplastic resin, capable of improving the operability at the time of mixing, capable of shortening the mixing time, and capable of heightening the generality, and further to provide a method for cross-linking the rubber or the thermoplastic resin by using the composition. SOLUTION: This cross-linking agent composition comprises an organic peroxide, an inorganic filler and a paraffinic hydrocarbon. A peroxyketal or a dialkylperoxide is preferable as the organic peroxide, and silicic acid or silicates are preferable as the inorganic filler. Preferably, the content of the organic peroxide is 20-60 wt.% and the content of the inorganic filler is 30-50 wt.%. The content of the paraffinic hydrocarbon is preferably 5-40 wt.%. The cross-linked material of the rubber or the thermoplastic resin is obtained by mixing the cross-linking agent composition with the rubber or the thermoplastic resin, and heat-treating the mixed product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crosslinking agent composition used for crosslinking rubber and a thermoplastic resin, and a crosslinking method using the same. More specifically, the present invention relates to a cross-linking agent composition capable of suppressing powdering during kneading into rubber or a thermoplastic resin, and a method for cross-linking a rubber or a thermoplastic resin using the same.

[0002]

2. Description of the Related Art Ethylene-propylene rubber (hereinafter referred to as EP)
R), ethylene-propylene-diene rubber (hereinafter abbreviated as EPDM) and acrylonitrile-
Rubbers such as butadiene rubber (hereinafter abbreviated as NBR), thermoplastic resins such as polyethylene (hereinafter abbreviated as PE) and ethylene-vinyl acetate copolymer (hereinafter abbreviated as EVA) are inexpensive. In addition, it has excellent physical properties and is widely used industrially. Since these rubbers and thermoplastic resins can be cross-linked by performing a heat treatment by adding an appropriate amount of an organic peroxide,
It is widely used as a method for improving its heat resistance.

[0003] When an organic peroxide is added to and mixed with a rubber or a thermoplastic resin, a method of using a pure organic peroxide is not preferable in terms of handling, and there is a problem in mixing properties. Therefore, a diluted product obtained by supporting an organic peroxide on an inorganic filler such as calcium carbonate, silica, clay or the like, or a diluted product obtained by diluting with an inorganic filler is generally used. Although such a diluted product has better handleability than a pure product, dusting occurs when kneading the rubber or thermoplastic resin with a Banbury mixer or a roll, and the working environment in which the worker inhales the powder. There was a problem. In addition, there is also a problem that the kneading requires a long time since the kneading is performed while suppressing the dusting.

As a method for solving such a problem, there has been proposed a master batch in which an organic peroxide is contained in a rubber or a thermoplastic resin to be crosslinked. The masterbatch containing this organic peroxide was developed with reference to the masterbatch widely used in the rubber field, such as carbon black, sulfur, pigments, vulcanization accelerators, and the content and type of organic peroxide. There are commercially available masterbatches containing various organic peroxides so that they can be appropriately selected according to the purpose. Master batches containing these organic peroxides can suppress powdering during addition and kneading operations, and have good mixing properties with rubber and thermoplastic resins, thus shortening the kneading time with a Banbury mixer or roll. For example, the process can be rationalized.

[0005] In order to obtain a crosslinked product having excellent physical properties, it is necessary to match the rubber or thermoplastic resin used as the base of the master batch with the rubber or thermoplastic resin to be crosslinked. In other words, if a master batch different from the rubber or thermoplastic resin whose base rubber or thermoplastic resin is to be cross-linked is likely to deteriorate the physical properties of the resulting cross-linked product, it is necessary to cope with both. There is.

[0006]

However, the types of rubbers and thermoplastic resins to be crosslinked are very large, and a huge number of types of masterbatches are produced, including differences in the molecular weight and the composition ratio of the copolymer. Therefore, there is a problem that versatility is poor. Therefore, development of a highly versatile crosslinking agent composition that suppresses dusting during kneading with rubber or thermoplastic resin has been desired.

The present invention has been made in view of such problems existing in the prior art. The purpose of the crosslinking agent is to suppress powdering during mixing with rubber or thermoplastic resin, to improve workability during mixing and to shorten mixing time, and to increase versatility. An object of the present invention is to provide a composition and a method for crosslinking a rubber or a thermoplastic resin using the composition.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and have found that a composition comprising an organic peroxide and an inorganic filler has a paraffinic carbon having a specific initial boiling point. It has been found that by including hydrogen, a cross-linking agent composition in which powdering during kneading into rubber or a thermoplastic resin is suppressed can be obtained. Furthermore, they have found that a cross-linked product having good physical properties can be obtained when this cross-linking agent composition is used as a cross-linking agent for rubber or a thermoplastic resin, thereby completing the present invention.

That is, the crosslinker composition of the first invention comprises an organic peroxide, an inorganic filler and a paraffinic hydrocarbon. The crosslinker composition of the second invention is the crosslinker composition according to the first invention, wherein the content of the organic peroxide is 20 to 60% by weight, the content of the inorganic filler is 30 to 50% by weight, and The content is 5 to 40% by weight.

[0010] A cross-linking agent composition according to a third invention is the cross-linking agent composition according to the first or second invention, wherein the organic peroxide is a peroxyketal or a dialkyl peroxide.
A method for crosslinking a rubber according to a fourth invention is a method for crosslinking a rubber in which a rubber and a crosslinking agent composition are mixed and then heat-treated, wherein the crosslinking agent composition is a crosslinking agent composition according to any one of the first to third inventions. It is characterized by being.

A method for crosslinking a thermoplastic resin according to a fifth aspect of the present invention comprises the steps of:
After mixing the thermoplastic resin and the cross-linking agent composition, in the method of cross-linking the thermoplastic resin by heating, the cross-linking agent composition has
The cross-linking agent composition according to any one of the above (1) to (3).

[0012]

Embodiments of the present invention will be described below in detail. The crosslinking agent composition of the present invention comprises an organic peroxide, an inorganic filler and a paraffinic hydrocarbon.

Any of the above-mentioned organic peroxides can be used as long as they can crosslink rubber or thermoplastic resin. Among them, peroxyketals and dialkyl peroxides having high hydrogen abstracting ability required for the crosslinking reaction can be used. Is particularly preferred. Specific examples of peroxyketal include, for example, 1,1-bis (t-butylperoxy) 3,
3,5-trimethylcyclohexane, 1,1-bis (t
-Butylperoxy) cyclohexane, n-butyl-
4,4-bis (t-butylperoxy) valerate and the like. Specific examples of dialkyl peroxides include, for example, dicumyl peroxide, di-t-butyl peroxide, di-t-hexyl peroxide, t-butylcumyl peroxide, 2,5-dimethyl-2,5- Bis (t-butylperoxy) hexane,
2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3,1,3-bis (t-butylperoxyisopropyl) benzene, 1,4-bis (t-butylperoxyisopropyl) Benzene and the like can be mentioned. Both peroxyketal and dialkyl peroxide,
One or more selected from these groups are appropriately selected and used.

The content of the organic peroxide in the crosslinking agent composition is preferably from 20 to 60% by weight, more preferably from 30 to 50% by weight. When the content is less than 20% by weight, it is necessary to increase the use amount of the crosslinking agent composition when adding a certain amount of the organic peroxide, and the cost may be increased accordingly. On the other hand, when the content exceeds 60% by weight, the upper limit of the oil absorption of the inorganic filler in the crosslinking agent composition is about 60% by weight, and the organic peroxide impregnated in the inorganic filler seeps from the inorganic filler. There is a risk of issuing.

Next, any inorganic filler can be used as long as it is generally blended with rubber or thermoplastic resin as a filler and is inert to organic peroxides. A substance that can adsorb or absorb organic peroxides.
Those in which H shows neutrality of 7 to 8 are preferred. In particular,
Examples thereof include silicates such as silicic acid, sodium silicate and calcium silicate, calcium carbonate, carbon black, talc, clay and the like, and one or more selected from these groups are appropriately selected and used. When an organic peroxide that is liquid at normal temperature is used, among these inorganic fillers, silicic acid and silicates having a high adsorption amount or high oil absorption amount are preferable.

The content of the inorganic filler in the crosslinking agent composition is preferably 30 to 50% by weight, more preferably 35 to 45% by weight. By setting the content of the inorganic filler in this range, dusting can be suppressed while maintaining the concentration of the organic peroxide in the crosslinking agent composition.

Next, any paraffinic hydrocarbon can be used as long as it is effective in preventing the inorganic filler from dusting.
Those having an initial boiling point of 200 ° C. or higher are preferred. When a paraffinic hydrocarbon having an initial boiling point of less than 200 ° C. is used, it is likely to bleed out from the surface of the rubber or the thermoplastic resin at the time of crosslinking or after the crosslinking, and the surface properties tend to deteriorate. In addition, the temperature at the time of crosslinking by kneading is usually less than 200 ° C., for example, 180 ° C.
Since the temperature is about ° C, paraffinic hydrocarbons are liable to evaporate during crosslinking, and the steam may deteriorate the working environment. The upper limit of the first boiling point is usually 300 to 35.
It is in the range of 0 ° C. Here, the initial boiling point refers to the initial distillation temperature during distillation.

Specific examples of the paraffinic hydrocarbon include, for example, Christol 52 (first boiling point: 200 ° C. or more) and Christol 70 (first boiling point: 2) manufactured by Esso Oil Co., Ltd.
Christol 72 (initial boiling point: 250 ° C or more), Christol 102 (initial boiling point: 250 ° C or more),
Christol 142 (initial boiling point: 250 ° C or more), Christol 172 (initial boiling point: 250 ° C or more), Christol 202 (initial boiling point: 250 ° C or more), Christol J-2
62 (initial boiling point: 300 ° C or higher), Christol 322
(Initial boiling point: 300 ° C or higher), Christol 352 (initial boiling point: 300 ° C or higher), Idemitsu Kosan Co., Ltd. Daphne oil CP-32N (initial boiling point: 300 ° C or higher), Daphne oil CP-38N (Initial boiling point: 250 ° C or more), Daphne oil CP-46N (Initial boiling point: 250 ° C or more), Daphne oil CP-68N (Initial boiling point: 250 ° C or more), Daphne oil KP-32 (Initial boiling point: 300 ° C or higher), Daphne oil KP-68 (initial boiling point: 250 ° C or higher), Daphne oil KP-100 (initial boiling point: 300 ° C or higher),
Process P-200 manufactured by Nikko Kyoishi Co., Ltd. (First boiling point: 25)
0 ° C. or higher), IP-Solvent 2028 (initial boiling point: 213 ° C.), IP-Solvent 28 manufactured by Idemitsu Petrochemical Co., Ltd.
35 (initial boiling point: 277 ° C.), and one or more selected from these groups are selected and used.

All of these paraffinic hydrocarbons can be used to suppress dusting during kneading of a crosslinking agent composition into rubber or a thermoplastic resin. However, paraffinic hydrocarbons during crosslinking of rubber can be used. In order to suppress the adverse effect on the cross-linking properties due to the volatilization of the polymer, those having a high initial boiling point and a higher content of the paraffin component are preferred.

The content of the paraffinic hydrocarbon varies depending on the content ratio of the organic peroxide to the inorganic filler in the crosslinking agent composition, but is preferably 5 to 40% by weight, more preferably 10 to 30% by weight. % By weight. When the content of the organic peroxide, which is a liquid component, is maintained in the range of 20 to 60% by weight to the extent that the organic peroxide does not exude from the inorganic filler, the content of the paraffinic hydrocarbon, which is also the liquid component, Is preferably in the above range.

The crosslinking agent composition can be produced by mixing the above-mentioned components. When manufacturing,
Using a mixer for powder such as a planetary mixer, a pony mixer, a Nauter mixer, and a tumbler,
It can be manufactured by mixing at a normal temperature of 0 ° C. for 5 minutes to 1 hour. At this time, if necessary, a uniform cross-linking agent composition can be produced by sieving with a suitable mesh sieve.

In preparing the crosslinking agent composition, an organic peroxide, an inorganic filler and a paraffinic hydrocarbon may be added and mixed simultaneously, but when an organic peroxide liquid at room temperature is used, Alternatively, an organic peroxide and a paraffinic hydrocarbon may be mixed in advance, and the mixture may be supported on an inorganic filler. When using an organic peroxide that is solid at room temperature, an organic peroxide and an inorganic filler are mixed in advance,
A paraffinic hydrocarbon may be supported on this mixture, and there is no particular limitation on the method and order of mixing.

Next, a crosslinking method using the crosslinking agent composition of the present invention will be described. The crosslinking agent composition can be used as a crosslinking agent for rubber or thermoplastic resin. In this case, all rubbers and thermoplastic resins which can be crosslinked by an organic peroxide can be used.

Specific examples of rubber include, for example, natural rubber,
Polyacrylate rubber, butadiene rubber, styrene-butadiene rubber, NBR, hydrogenated NBR, EP
R, EPDM, silicone rubber, urethane rubber, fluorine rubber and the like. Crosslinking with an organic peroxide is intended to improve the heat resistance and compression set of rubber products in particular, so that rubbers used include NBR, hydrogenated NBR,
EPR, EPDM, silicone rubber, urethane rubber and fluorine rubber are preferred, and hydrogenated NBR, EPR, EP
DM, silicone rubber and fluoro rubber are particularly preferred.

On the other hand, specific examples of the thermoplastic resin include, for example, PE, EVA, chlorinated PE, and chlorosulfonated P.
E, polybutylene, polyisobutylene and the like.
When the crosslinking agent composition of the present invention is used as a crosslinking agent for a rubber or a thermoplastic resin, the amount added depends on the crosslinking temperature, the desired crosslinking time, and the like, but as a pure organic peroxide, the rubber or the thermoplastic resin is used. It is preferably 0.1 to 100 parts by weight.
It is 3 to 15 parts by weight, more preferably 0.5 to 10 parts by weight. When the addition amount of the organic peroxide as a pure component is less than 0.3 parts by weight, the crosslinking time becomes extremely long and the crosslinking tends to be insufficient. On the other hand, when the pure addition amount is 15
If the amount exceeds the weight part, the crosslinked product tends to be hard and brittle.

In the crosslinking method using the crosslinking agent composition, a crosslinking assistant can be used in combination. Specific examples of the crosslinking aid include, for example, ethylene glycol dimethacrylate, butylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, trimethylolpropane trimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, and polyethylene glycol. Dimethacrylate, pentaerythritol trimethacrylate, ethylene glycol diacrylate, butylene glycol diacrylate, 1,3-butylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, pentaerythritol triacrylate,
Triallyl cyanurate, triallyl isocyanurate, N, Nm-phenylenebismaleimide, polybutadiene and the like.

Further, if necessary, various additives such as an antioxidant, an ultraviolet absorber, a plasticizer, a lubricant, a flame retardant, a foaming agent and a pigment can be used in combination. As an antioxidant, 4,4-thiobis (3-methyl-6-t-
Phenol-based compounds such as butylphenol), 2,5-di-t-butylhydroquinone, 2,6-di-t-butyl-p-cresol, phosphorus-based compounds and bis (2-methyl-4- (3-n- Alkylthiopropionyloxy) -5-t-butylphenyl) sulfide, 2,2-
Thiodiethylenebis (3- (3,5-t-butyl-4-
Sulfur-based compounds such as (hydroxyphenyl) propionate and dilaurylthiopropionate. Examples of the lubricant include stearic acid and zinc stearate.

The mixing of the crosslinking agent composition of the present invention and the above-mentioned additives into rubber or thermoplastic resin can be carried out by a known method. Specifically, the kneading is performed by kneading with an open or closed kneader such as a roll, a Banbury mixer, an intermix, a pressure kneader, and a screw mixer.

The crosslinking of rubber or thermoplastic resin using the crosslinking agent composition of the present invention can be carried out by a press or an extruder.
50 to 210C, preferably 10 to 160C to 200C.
The heat treatment is performed for 60 minutes, more preferably for 15 to 40 minutes.

The effects exerted by the above embodiments will be summarized below. According to the above-mentioned cross-linking agent composition, the bulk specific gravity can be increased by adding a paraffinic hydrocarbon which is a liquid component to the organic peroxide impregnated in the inorganic filler. For this reason, powdering when the crosslinking agent composition is mixed (usually kneaded) with the rubber or the thermoplastic resin can be suppressed.

Since powdering when the cross-linking agent composition is mixed with rubber or thermoplastic resin can be suppressed in this way, workability during mixing can be improved and the mixing time can be reduced. Can be planned.
Therefore, the versatility of the crosslinking agent composition can be improved.

The content of the organic peroxide is from 20 to
By setting the content of the inorganic filler in the range of 30 to 50% by weight and the content of the paraffinic hydrocarbon in the range of 5 to 40% by weight, the above effects can be more effectively exhibited. it can.

By using peroxyketal or dialkyl peroxide as the organic peroxide, it is possible to improve the hydrogen extraction ability required for a crosslinking reaction of rubber or a thermoplastic resin.

According to the rubber cross-linking method using the cross-linking agent composition, the rubber can be rapidly cross-linked under a heated atmosphere, and the physical properties of the obtained cross-linked product, for example, tensile strength, elongation, and hardness Etc. can be maintained favorably.

According to the method for crosslinking a thermoplastic resin using the crosslinking agent composition, the thermoplastic resin can be rapidly crosslinked in a heated atmosphere, and the physical properties of the obtained crosslinked product, for example, tensile strength , Elongation, hardness, etc. can be maintained satisfactorily.

[0036]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. The abbreviations of organic peroxides and paraffinic hydrocarbons used in each example indicate the following compounds,
Parts and% represent parts by weight and% by weight, respectively. (Organic peroxide) 3M: 1,1-bis (t-butylperoxy) 3
3,5-trimethylcyclohexane [Nippon Oil & Fats Co., Ltd.
V: n-butyl-4,4-bis (t-butylperoxy) valerate [manufactured by NOF CORPORATION, trade name: Perhexa V, purity 90%] 25B: 2 , 5-dimethyl-2,5-bis (t-butylperoxy) hexane [manufactured by NOF Corporation, trade name: Perhexa 25B, purity: 90%] DCP: dicumyl peroxide [manufactured by NOF Corporation,
Trade name Parkmill D, purity 98%] P: 1,3-bis (t-butylperoxyisopropyl) benzene [manufactured by NOF Corporation, trade name: perbutyl P, purity: 95%] (paraffin hydrocarbon) 52 : Paraffinic hydrocarbon manufactured by Esso Oil Co., Ltd.
Brand name Christol 52, first boiling point: 200 ° C or more 68N: Idemitsu Kosan Co., Ltd. paraffinic hydrocarbon, trade name Daphne Oil CP-68N, first boiling point: 250 ° C or more 262: Esso Oil Co., Ltd. paraffin Series hydrocarbons,
Christol J-262, initial boiling point: 300 ° C. or higher 1620: Idemitsu Petrochemical Co., Ltd. paraffin hydrocarbon, IP-solvent 1620, initial boiling point: 166 ° C. The test items in each example are as follows: Was performed according to

(Angle of repose) Using a funnel having an inner diameter of 10 mm,
Sample 10 of the crosslinker composition from a height of 10 cm above the horizontal plane
0 g was allowed to fall naturally, and the angle between the inclined surface of the accumulated cone and the horizontal plane was measured and defined as the angle of repose. The angle of repose is an index that indicates the fluidity of the powder.The smoother the powder is, the higher the powderiness is, the higher the fluidity is.The smaller the angle of repose, the lower the powderiness, the more fluid the powder is. Low, showing a large angle of repose.

(Presence / absence of powdering) The crosslinker composition was mixed with a rubber compound on a 6-inch roll or PE in a Banbury mixer.
The presence or absence of powdering when added to and mixed with the formulation was visually evaluated.

(Tensile properties) A tensile test (tensile speed: 500 mm / min, ambient temperature: 23 ° C) of a crosslinked rubber punched out in a No. 3 dumbbell shape according to JIS K6251 was carried out, and tensile strength and elongation at break were measured. It was measured.

(Hardness) The hardness (Shore A) of the crosslinked rubber was measured according to JIS K6253. (Heat Aging Resistance) According to JIS K 6257, a cross-linked rubber punched into a No. 3 dumbbell was heat-aged at 125 ° C. for 72 hours by a gear type aging tester, and then subjected to the above-mentioned tensile test. The rate of change in strength and the rate of change in elongation during cutting were determined.

(Presence / absence of paraffin-based hydrocarbon bleeding on rubber surface) In the heat aging test, the presence / absence of paraffin-based hydrocarbon bleeding on the crosslinked rubber surface after the aging test was visually evaluated.

(Cross-Linking Performance) A cross-linking test of PE was performed using a Curastometer V type manufactured by JSR, and a maximum torque value and a time (T90) until reaching 90% of the maximum torque value were measured.

(Presence / absence of paraffin-based hydrocarbon bleeding to PE surface) The crosslinked PE obtained in the PE crosslinking test by the above curast meter was left for 72 hours in a gear type aging tester set at 125 ° C. The presence or absence of seepage of the paraffinic hydrocarbon on the surface of the crosslinked PE was visually evaluated.

Example 1 35.6 parts of silicic acid (Zeoseal 500V manufactured by Taki Kagaku Co., Ltd.) was added as an inorganic filler to a pressure-type kneader, and 4M of 3M was added as an organic peroxide.
4.4 parts and 20 parts of 68N as a paraffinic hydrocarbon were added and mixed for 15 minutes. Next, the mixture was passed through a 12-mesh sieve and further mixed for 15 minutes using a pressure kneader to produce a powdery crosslinking agent composition. Then, the angle of repose of the crosslinker composition was measured, and the results are shown in Table 1.

[0045]

[Table 1]

(Examples 2 and 3) A powdery crosslinking agent composition was produced in the same manner as in Example 1 except that the kind of the paraffinic hydrocarbon was changed as shown in Table 1. Then, each angle of repose was measured, and the results are shown in Table 1.

Example 4 A powdery crosslinking agent composition was produced in the same manner as in Example 1 except that the kind of the paraffinic hydrocarbon was changed as shown in Table 1. The angle of repose was measured, and the results are shown in Table 1. In addition, this Example 4
The initial boiling point of the paraffinic hydrocarbon used in the above is 166 ° C.

Comparative Example 1 A powdery crosslinking agent composition was produced in the same manner as in Example 1 except that the paraffinic hydrocarbon was not added and the amount of silicic acid was increased accordingly. The angle of repose was measured, and the results are shown in Table 1.

Examples 5 to 8 Powdered crosslinking agent compositions were produced in the same manner as in Example 1 except that the amounts of 3M, silicic acid and paraffinic hydrocarbon were changed as shown in Table 1.
Then, each angle of repose was measured, and the results are shown in Table 2.

Example 9 A powdery crosslinking agent composition was produced in the same manner as in Example 1 except that V was used instead of 3M as the organic peroxide. And measure the angle of repose,
The results are shown in Table 2.

[0051]

[Table 2]

Example 10 A powdery crosslinking agent composition was produced in the same manner as in Example 1 except that 25B was used instead of 3M as the organic peroxide. The angle of repose was measured, and the results are shown in Table 3.

Comparative Example 2 A powdery crosslinking agent composition was produced in the same manner as in Example 10 except that the paraffinic hydrocarbon was not blended and the amount of silicic acid was increased accordingly. The angle of repose was measured, and the results are shown in Table 3.

(Example 11) In a pressurized kneader, 54.2 parts of light calcium carbonate (calcices manufactured by Kamishima Chemical Co., Ltd .; hereinafter abbreviated as charcoal) was used as an inorganic filler, and DCP was used as an organic peroxide. Add 8 parts and premix for 10 minutes. There, 262 was added as a paraffinic hydrocarbon.
Parts were added and mixed for 10 minutes. Next, the mixture was passed through a 12-mesh sieve and further mixed for 15 minutes using a pressure kneader to produce a powdery crosslinking agent composition. The angle of repose was measured, and the results are shown in Table 3.

Example 12 DCP was used as an organic peroxide.
Example 11 except that P was used in place of, and the amounts of light calcium carbonate and organic peroxide were changed as shown in Table 3.
A powdery crosslinking agent composition was produced in the same manner as described above. And
The angle of repose was measured, and the results are shown in Table 3.

Comparative Example 3 A powdery crosslinking agent composition was produced in the same manner as in Example 12 except that paraffin-based hydrocarbons were not added and the amount of carbon was increased accordingly. The angle of repose was measured, and the results are shown in Table 3.

[0057]

[Table 3]

As shown in Tables 1 to 3, the angle of repose of the crosslinker compositions of Examples 1 to 12 containing paraffinic hydrocarbons was the same as Comparative Examples 1 to 3 containing no paraffinic hydrocarbons.
Was larger than the angle of repose of the cross-linking agent composition, and the incorporation of a paraffinic hydrocarbon was effective in preventing dusting.

Example 13 EPDM (Mitsui Chemicals, Inc.)
100 parts of EPT-4021), 40 parts of HAF carbon black, 5 parts of zinc white, and 0.5 part of stearic acid were preliminarily kneaded on a 6-inch roll. Thereto, 2.5 parts of the crosslinking agent composition obtained in Example 1 was added and mixed, and the presence or absence of powdering at that time was evaluated. Next, the obtained compounded rubber sheet was
Press-crosslinking was performed at 150 ° C. for 30 minutes under a pressure of 30 kg / cm ² to prepare a crosslinked rubber. Then, various physical properties (tensile physical properties, hardness, heat aging resistance) were tested using this crosslinked rubber. Furthermore, the presence or absence of seepage of paraffinic hydrocarbons on the rubber surface after the aging test was evaluated. Table 4 shows the composition and test results.

Example 14 Table 4 shows the types of the crosslinking agent composition.
A compounded rubber sheet was produced in the same manner as in Example 13 except that the composition was changed as shown in Example 13, and the presence or absence of dusting during addition and mixing of the crosslinking agent composition was evaluated. The compounded rubber sheet was press-crosslinked in the same manner as in Example 13 to produce a crosslinked rubber. Then, various physical property tests were performed in the same manner as in Example 13, and the results are shown in Table 4.

(Example 15) Table 4 shows the types of the crosslinking agent composition.
A compounded rubber sheet was produced in the same manner as in Example 13 except that the composition was changed as shown in Example 13, and the presence or absence of dusting during addition and mixing of the crosslinking agent composition was evaluated. The compounded rubber sheet was press-crosslinked in the same manner as in Example 13 to produce a crosslinked rubber. Then, various physical property tests were performed in the same manner as in Example 13, and the results are shown in Table 4. The paraffinic hydrocarbon (162) in the crosslinking agent composition used in Example 15 was used.
The initial boiling point of 0) is 166 ° C.

(Comparative Example 4) A compounded rubber sheet was prepared in the same manner as in Example 13 except that the type of the crosslinking agent composition was changed as shown in Table 4, and the powdering during addition and mixing of the crosslinking agent composition was performed. Was evaluated. The compounded rubber sheet was press-crosslinked in the same manner as in Example 13 to produce a crosslinked rubber. Then, various physical property tests were performed in the same manner as in Example 13, and the results are shown in Table 4. The cross-linking agent composition used in this comparative example did not contain a paraffinic hydrocarbon and was a cross-linking agent composition outside the present invention.

[0063]

[Table 4]

Example 16 A compounded rubber sheet was prepared in the same manner as in Example 13 except that the type of the crosslinking agent composition and the crosslinking temperature were changed as shown in Table 5, and the mixing and mixing of the crosslinking agent composition was carried out. The presence or absence of dusting was evaluated. Example 1
In the same manner as in 3, the compounded rubber sheet was press-crosslinked to produce a crosslinked rubber. Then, various physical property tests were performed in the same manner as in Example 13, and the results are shown in Table 5.

(Comparative Example 5) A compounded rubber sheet was prepared in the same manner as in Example 12 except that the type of the crosslinking agent composition and the crosslinking temperature were changed as shown in Table 5, and when the crosslinking agent composition was added and mixed. The presence or absence of dusting was evaluated. Example 13
In the same manner as described above, the compounded rubber sheet was press-crosslinked to produce a crosslinked rubber. Then, various physical property tests were performed in the same manner as in Example 13, and the results are shown in Table 5. The cross-linking agent composition used in this comparative example did not contain a paraffinic hydrocarbon and was a cross-linking agent composition outside the present invention.

Example 17 A compounded rubber sheet was prepared in the same manner as in Example 13 except that the type and amount of the cross-linking agent composition and the cross-linking temperature were changed as shown in Table 5. The presence or absence of dusting at the time of addition and mixing was evaluated. The compounded rubber sheet was press-crosslinked in the same manner as in Example 13 to produce a crosslinked rubber. Then, various physical property tests were performed in the same manner as in Example 13, and the results are shown in Table 5.

Comparative Example 6 Example 1 was repeated except that the type and amount of the crosslinking agent composition and the crosslinking temperature were changed as shown in Table 5.
A compound rubber sheet was prepared in the same manner as in No. 3, and the presence or absence of dusting during addition and mixing of the crosslinking agent composition was evaluated. Also,
The compounded rubber sheet was press-crosslinked in the same manner as in Example 13 to produce a crosslinked rubber. Then, various physical property tests were performed in the same manner as in Example 13, and the results are shown in Table 5. The cross-linking agent composition used in this comparative example did not contain a paraffinic hydrocarbon and was a cross-linking agent composition outside the present invention.

[0068]

[Table 5]

As is clear from comparison between Examples 13 and 14 and Comparative Example 4 in Table 4, Example 16 and Comparative Example 5, and Example 17 and Comparative Example 6 in Table 5, a paraffinic hydrocarbon was blended. The crosslinker composition of the present invention has no dusting during kneading to rubber. Further, the rubber could be rapidly crosslinked in a heated atmosphere, and a crosslinked product having good physical properties was obtained. In particular, it was characteristic that a crosslinked product having a large elongation at the time of cutting was obtained.

On the other hand, as is clear from comparison between Examples 13 and 14 and Example 15 in Table 4, the initial boiling point was 200
When a cross-linking agent composition containing a paraffin-based hydrocarbon at a temperature of at least 100 ° C. is used, the paraffin-based hydrocarbon does not seep out from the surface of the cross-linked rubber, whereas the initial boiling point is 200.
When a cross-linking agent composition containing a paraffin-based hydrocarbon having a temperature of less than ° C was used, the paraffin-based hydrocarbon oozed out of the surface of the cross-linked rubber and the surface properties were slightly reduced.

Example 18 PE (Sumitomo Chemical Industries, Ltd.)
Sumikasen G806) and 20 parts of HAF carbon black were kneaded in a Banbury mixer. Thereto, 2.5 parts of the crosslinking agent composition obtained in Example 1 was added and mixed, and the presence or absence of powder at that time was evaluated. Next, the obtained PE compound was mixed with a curastometer for 150 minutes.
Crosslinking was performed at 30 ° C. for 30 minutes, and the crosslinking performance was evaluated. further,
After the aging test, the presence or absence of seepage of paraffinic hydrocarbons on the PE surface was evaluated. Table 6 shows the composition and the test results.

Example 19 Table 6 shows the types of the crosslinking agent composition.
Except that PE was replaced as shown in Example 18 in the same manner as in Example 18.
A compound was prepared, and the presence or absence of dusting during addition and mixing of the crosslinking agent composition was evaluated. In addition, the crosslinking performance of the PE compound was evaluated in the same manner as in Example 18, and the results are shown in Table 6.

Example 20 Table 6 shows the types of the crosslinking agent composition.
Except that PE was replaced as shown in Example 18 in the same manner as in Example 18.
A compound was prepared, and the presence or absence of dusting during addition and mixing of the crosslinking agent composition was evaluated. In addition, the crosslinking performance of the PE compound was evaluated in the same manner as in Example 18, and the results are shown in Table 6. The initial boiling point of the paraffinic hydrocarbon (1620) in the crosslinking agent composition used in Example 20 was 166 ° C.

(Comparative Example 7) A PE compound was prepared in the same manner as in Example 18 except that the type of the crosslinking agent composition was changed as shown in Table 6, and dusting during addition and mixing of the crosslinking agent composition was performed. The presence or absence was evaluated. In addition, the crosslinking performance of the PE compound was evaluated in the same manner as in Example 18, and the results are shown in Table 6. The crosslinking agent composition used in Comparative Example 7 did not contain a paraffinic hydrocarbon and was a crosslinking agent composition outside the scope of the present invention.

[0075]

[Table 6]

Examples 18 and 19 in Table 6 and Comparative Example 7
As is clear from the comparison, the cross-linking agent composition of the present invention containing a paraffinic hydrocarbon did not powder when kneaded with PE. Further, in a heating atmosphere, P
E could be rapidly crosslinked, and a crosslinked product having good physical properties was obtained.

On the other hand, as is clear from comparison between Examples 18 and 19 and Example 20 in Table 6, the first boiling point was 200
When a cross-linking agent composition containing a paraffinic hydrocarbon at a temperature of at least ° C was used, the paraffinic hydrocarbon did not seep out from the surface of the crosslinked PE. In contrast, when a crosslinking agent composition containing a paraffinic hydrocarbon having an initial boiling point of less than 200 ° C. is used, seepage of the paraffinic hydrocarbon from the surface of the crosslinked PE and a slight decrease in surface properties did.

The technical idea grasped from the above embodiment will be described below. The paraffinic hydrocarbon has an initial boiling point of 200;
The crosslinking agent composition according to any one of claims 1 to 3, wherein the crosslinking agent composition has a temperature in the range of -350 ° C.

In such a configuration, it is possible to prevent the paraffin-based hydrocarbon from seeping out from the surface of the rubber or thermoplastic resin at the time of cross-linking or after cross-linking, and to suppress the deterioration of the surface property. Evaporation can be suppressed to prevent the working environment from deteriorating.

The crosslinking agent composition according to any one of claims 1 to 3, wherein the inorganic filler is a silicic acid or a silicate. With this configuration, the amount of adsorption or oil absorption to the organic peroxide can be increased.

[0081]

As described in detail above, according to the present invention, the following excellent effects can be obtained. That is, according to the cross-linking agent composition of the first invention, dusting during mixing with rubber or thermoplastic resin can be suppressed, workability during mixing can be improved, and mixing time can be shortened. Can be enhanced.

Further, according to the crosslinking agent composition of the second invention, the effects of the first invention can be exhibited more effectively. Further, according to the cross-linking agent composition of the third invention, in addition to the effects of the first or second invention, it is possible to improve the hydrogen extraction ability required for a cross-linking reaction of rubber or a thermoplastic resin.

According to the rubber crosslinking method of the fourth invention, the rubber can be rapidly crosslinked in a heated atmosphere, and a crosslinked product having good physical properties can be obtained. According to the thermoplastic resin crosslinking method of the fifth invention, the thermoplastic resin can be rapidly crosslinked in a heated atmosphere, and a crosslinked product having good physical properties can be obtained.

Claims (5)

[Claims] 1. A cross-linking composition comprising an organic peroxide, an inorganic filler and a paraffinic hydrocarbon. 2. The content of the organic peroxide is 20 to 60.
The crosslinking agent composition according to claim 1, wherein the content of the inorganic filler is 30 to 50% by weight, and the content of the paraffinic hydrocarbon is 5 to 40% by weight. 3. The crosslinking agent composition according to claim 1, wherein the organic peroxide is a peroxyketal or a dialkyl peroxide. 4. A method for crosslinking a rubber, wherein the rubber and the crosslinking agent composition are mixed and then heat-treated, wherein the crosslinking agent composition comprises
4. A method for crosslinking a rubber, which is the crosslinking agent composition according to any one of claims 1 to 3. 5. After mixing the thermoplastic resin and the crosslinking agent composition,
A method for crosslinking a thermoplastic resin to be heated, wherein the crosslinking agent composition is the crosslinking agent composition according to any one of claims 1 to 3.