JPS59204636A - Composition for rubber chafer - Google Patents

Abstract

PURPOSE:The titled composition having low Mooney viscosity, improved processing properties, providing a vulcanized material having high modulus of elasticity and pico abrasion index, containing a specific rubber reinforced composition, consisting of components in a specific ratio. CONSTITUTION:A composition consisting of (A) a rubber reinforced composition wherein 5-100pts.wt. fine thin short fibers of thermoplastic polymer containing -CONH- group in the polymer chain is embedded in 100pts.wt. vulcanizable rubber and the polymer is grafted onto the rubber through the a precondensate of phenol-formaldehyde resin at the interfaces of the fibers, (B) natural and/or polyisoprene, (C) diene rubber except the component B, and (D) 50-70pts.wt. carbon black based on 100pts.wt. total amounts of the rubber components in such a way that an amount of the polymer in the component A is 1-15pts.wt. based on 100pts.wt. total amounts of the rubber components, and total amounts of the rubber in the components A and B are 20-50wt% based on total rubber components, of a vulcanized material having >=30kg/cm<2> modulus at 100%, and >=200 pico abrasion index designated by ASTM D2228.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rubber chafer composition that has a low Mooney viscosity (ML) and excellent processability.

Recently, with the development of expressways, high-speed performance of tires has become increasingly required, and in order to prevent movement that occurs at the bead, rubber with a sieve elastic modulus has come to be used around the bead. Ta.

For this reason, an increasingly large force was applied to the rubber chafer placed between the rim and the door.
High breaking strength is now required.

The bead part is attached and fixed to the metal rim.

Parts of the rim that come into contact with the flange, etc., are particularly susceptible to damage (due to rim rubbing). Therefore, in this contact area.

A reasonable modulus of elasticity is required for purposes such as preventing rim rubbing and wear and increasing cornering power.

Various methods have been tried in the past to obtain rubber with a high modulus of elasticity. The method of blending a large amount of carbon black is difficult because the rubber does not stick together during the processing process, the power load increases during kneading and extrusion, and the compound ML increases, causing problems during tire molding. I don't like it.

The method of blending sulfur with sulfur has disadvantages such as blooming of sulfur and faster crack growth due to increased crosslink density. Addition of thermosetting resin.

Since thermosetting 11'+1 fat has low compatibility with commonly used natural rubber and diene rubber, it is difficult to obtain good dispersion if a large amount is blended. Furthermore, since this kneaded dough is hard even when unvulcanized, the load increases during blending and extrusion, and the workability of forming tires is poor. The method of simply blending short fibers is
Due to insufficient bonding between short fibers and rubber, creep increases and fatigue life decreases.

As a result of intensive research aimed at obtaining a rubber chafer composition with a high elastic modulus and pico abrasion index of a vulcanizate and a low Mooney viscosity, the inventors have developed a specific reinforced rubber composition used in the present invention. The present invention was completed based on the discovery that the above object can be achieved by blending each component in a specific ratio.

That is, the present invention provides vulcanizable rubber 100? 10 = NH- group in the polymer molecule in parts by weight 5
5 to 100 parts by weight of fine short fibers of f-plastic polymer are embedded, and at the interface of the fibers, the polymer and vulcanizable rubber are grafted via an initial condensate of a two-enol formaldehyde resin. A reinforced rubber composition (A) containing natural rubber, polyisoprene or a mixture of both (B), a diene rubber (C) excluding natural rubber and polyisoprene, and carbon black (D), The present invention also relates to a rubber chafer composition that satisfies the following conditions (1) to (1v).

(i) The deposit of the Maeko 1 Shinetsucho Q-4J'lE polymer is 1 to 15 parts by weight based on the total weight of the rubber component: 100 parts.

(ii) The ratio of rubber is such that the total amount of natural rubber or polyimprene in component (A) and component (B) is 20 to 50.
It is a heavy burial mound.

(iiQ Carbon black is 50 to 7 parts by weight based on 100 parts by weight in total of the rubber components.

Ov) Additions and additions to the composition are 100% modi-
Lass is 30” damn/CTlf or higher and ASTM
The pico-j pillow index specified in D2228 is 200 or more.

The rubber chafer composition of the present invention has a small Mooney viscosity (MLI+4 (100"C) or less, sometimes simply abbreviated as ML), and a 100% modulus of the vulcanizate (hereinafter also simply abbreviated as Mloo). Yes) is 3 Q
ky/rJJ dei"2, A, STM D222
The pico wear index specified in No. 8 is 200 or more.

It has excellent processability, has a high elastic modulus of +R material, and has good abrasion resistance.

In this invention, 5 to 100 parts by weight of fine staple fibers of a thermoplastic polymer having -6-NH- groups in the polymer molecule are added to 100 parts by weight of the vulcanizable rubber.

Preferably 20 to 100 parts by weight are embedded.

It is also necessary to blend a reinforced rubber composition in which the polymer and vulcanizable rubber are grafted via an initial condensate of phenol-formaldehyde resin at the interface of the fibers. Even though fibers are blended, a rubber composition with excellent moldability can be obtained.

The vulcanizable rubbers mentioned above include natural rubber, cis-1,
4 polybutadiene, polyisoprene, styrene-butadiene copolymer rubber, isoprene-isobutylene copolymer, and the like.

Among these rubbers, natural rubber is preferred.

The fine short fibers of the thermoplastic polymer have a melting point of 19
Nylon 6, Nylon 610. Nylon 12. Nylon 6]-Soil, nylon such as Bouillon 612, polyhegetamethylene urea, polyundecamethylene urea, and is formed from nylon with an average diameter of 0°05~O.f3μ and a circular cross section, the shortest fiber. The length is preferably 1μ or more, and the molecules are arranged in the direction of the fiber axis, and the fibers are embedded in the carbonizable rubber in the form of fine short fibers.

The available rubber is phenol formaldehyde type (jl
It is grafted via an initial condensate of fat.

The first jlJi of the above-mentioned phenol formaldehyde resin
The condensate I can be an initial condensate of resol type or novolac type phenol formaldehyde resin. Among these, novolak type phenol formaldehyde type (☆ is an initial condensation product of fat (1ν, lower half V is sometimes abbreviated as novolak) is preferable.

The above-mentioned novolac is a catalyst that is known per se.

For example, a soluble soluble product obtained by a condensation reaction of phenols such as phenol, bisphenols, and formaldehyde (or paraformaldehyde) using an acid such as sulfuric acid, hydrochloric acid, phosphoric acid, or oxalic acid as a catalyst. resin and its modified products. 1 for example as novolak.

novolac type phenol formaldehyde initial condensate,
Novolak-type lactam-bisphenol P-formaldehyde initial condensate, novolak-type styrenated phenol-phenol-formaldehyde initial condensate, etc. can be suitably used.

In this invention, in the reinforced rubber composition used, the strength of the fine short fibers of the thermoplastic polymer having one δNH- group in one molecule of the polymer embedded in the vulcanizable rubber is high, and At the interface of the short fibers, the thermoplastic polymer and the vulcanizable rubber are graft-bonded, preferably via a novolac, so that the vulcanizate has a high elastic modulus and pico abrasion index, and a rubber chafer with a small ML. For i r1. I'i! ? 4. It is possible to call for peace.

In this invention Vζ, 11. -6-N in the polymer molecule which is 1:I grafted onto the vulcanizable rubber.
The proportion of fine short fibers of heat-curable polymers with H-no, 1ζ is added (1iffiable rubber 100 li:
A weight reinforced rubber composition is used with 5 to 100 parts of the fiber per section.

Particularly, in this invention, the weight of fine short fibers of a thermoplastic polymer embedded in a rubber capable of
18: The proportion of monomer of vulcanizable rubber grafted to the thermoplastic polymer via novolac at the interface of the fiber (vulcanizable rubber/fine short fibers of thermally curable polymer) The thermoplastic polymer forming the fiber and the vulcanizable rubber are preferably graft-bonded via a novolac so that the indicated graft ratio is 3 to 25% by weight, particularly 5 to 20% by weight. preferable.

The reinforced rubber composition according to the present invention having the characteristics described above can be used for example, for example, in 1 minute with vulcanizable rubber. -) + (20oooo 10N in undropped polymer molecule)
Thermoplastic polymer having an H-group, and 0.2 to 5 per 100 parts by weight of the total amount of these rubbers and thermoplastic polymer.
t parts by weight of the initial condensate of a novolanque-type phenol formaldehyde resin and a formaldehyde donor are kneaded at a temperature above the melting point of the thermoplastic polymer and below 270°C, and the resulting kneaded product is mixed with the rubber in the mixed wire. The proportion of thermoplastic polymer is rubber.

When the thermoplastic polymer is 5 to 10.0 parts by weight per 100 parts by weight, the ratio of the rubber and thermoplastic polymer in the mixed wire is more than 5 parts by weight per 100 parts by weight of rubber. If necessary, additional vulcanizable rubber may be added to the mix to give a ratio of 5 to 100 parts by weight of thermoplastic polymer per 100 parts by weight of total rubber, and further at a temperature above the melting point of the thermoplastic polymer and 2'? '
It can be produced by a method of kneading at a temperature of 0°C or lower, extruding at a temperature higher than the melting point of the thermoplastic polymer and 270°C or lower, and stretching the extrudate at a temperature lower than the melting point of the thermoplastic polymer. .

As the formaldehyde donor, a compound that generates formaldehyde upon heating is used. For example, as a formaldehyde donor.

Hexamethylenetetramine, acetaldehyde ♀■'' Ammonia ° (H1-CH-NH2) 1.noζ-la formaldehyde, α-polyoxine methylene, polyvalent methio-lumelamine derivative, oxazolidine derivative, polyvalent methylolated acetylene urea Examples include.

In the above method (d) using the above novolak and formaldehyde donor, knead the heatable cob, the thermoplastic polymer having -LNH- groups in the polymer molecule, the novolak and the formaldehyde body for 7 h). By this, the vulcanizable rubber and the thermoplastic polymer are graft-bonded via the novolak, and the thermoplastic polymer is dispersed in the vulcanizable rubber in a small amount. (The particle size of the plastic polymer is usually 1 to 2 μm).

In the above method, by stretching the extrudate, the force pM1 of the resulting reinforced comb composition is such that the thermoplastic polymer in the rubber is converted into a fibrous structure with the fibers oriented towards themselves (V). The result is fine short fibers with great strength.

A reinforced rubber composition obtained by the above method.

100 parts by weight of vulcanizable rubber Todoroki 5・100M
amount? A thermoplastic polymer having 10 NH- groups is contained in the polymer molecule of the part, the thermoplastic polymer is fine short fibers, and the thermoplastic polymer and the vulcanizable rubber are bonded to the novolac at the interface of the fibers. It is graft-bonded via.

The composition for rubber chafer of the present invention comprises the above-mentioned reinforced rubber composition (A), natural rubber, polyisoprene or a mixture of both (B), natural comb and die/based rubber excluding polyisoprene (C), and carbon. Black (D)
It is made by blending.

Examples of the nodiene rubber (0) include X-1',4-IJ7 lydiene, styrene-butadiene copolymer, isoprene-isobutylene copolymer, and the like.

Carbon black has a particle size of 90 mμ or less and a dibutyl phthalate (D'BP) oil absorption of 70 + p/! /
1009 or more is preferably used. As a carbon blank, for example, HA. F, FF, FEF
.

GPF, SAIi', I SA. One scale of each scale such as F, SRF, Carbo/Black is used.

Mae Station Each component <i, (+) 111 of the heat-giving polymer (矧狛') is the golden rule of the rubber component 1: t'oo heavy fan: 1 to 5 parts, Preferably, it is 2 to 15 parts by weight, and (ii) the proportion of rubber is the natural rubber in component (A), and the total amount of polyimprene and component (B) is 20
(i:1) The amount of carbon blank is 50 to 70 parts by weight based on the total 100 parts by weight of the rubber components, (iv) The addition of the composition (l+ft is 10% by weight)
0% modulus is "O"9/lar1: or more,
It is blended to satisfy the following conditions stipulated in ASTM D2228: 1 thread wear index is 200 or more.

6iJ pjy DJ If the amount of the plastic polymer is less than the above-mentioned below, lvl ] is small and a composition with a high elastic modulus and pico wear index of the vulcanizate cannot be obtained, and if the +- of the thermoplastic polymer is more than the above-mentioned upper limit. The ML of the composition increases. If the blending ratio of natural rubber or polyisoprene is outside the above range, the number of bends of the vulcanizate tends to decrease. When the amount of carbon black is less than the above-mentioned lower limit, the pico wear index of the vulcanizate becomes small, and when the amount of carbon black is more than the above-mentioned upper limit, the ML of the composition becomes large. It's ox.
If the M 100 and pico wear index of the vulcanizate are outside the above ranges, it is not suitable as a composition for comb chafers.

The rubber chafer composition of the present invention is prepared by mixing the above-mentioned components in a kneading machine such as a Banbury mixer or a roll.
It can be obtained by heating at 180°C for about 1 to 60 minutes.

The rubber chafer composition of the present invention contains additives such as a vulcanizing agent.

The vulcanizing agent is a known vulcanizing agent, such as sulfur.

Organic peroxidants, sulfur-containing compounds, etc. can be used. There are no particular restrictions on the method of blending the vulcanizing agent into the rubber composition, and any known blending method may be employed. Along with the vulcanizing agent, Tsukithite carbon, activated calcium carbonate, ultrafine magnesium silicate, no-istyrene resin, coumaron indene resin, phenolic resin,
Reinforcing agents such as lignin, modified melamine resin, and oil resin,
Each heavy gray carbon Rh lucium, basic magnesium carbonate, clay, 111I-lead, diatomaceous earth, recycled rubber, powdered rubber, fillers such as ebonite powder, aldehydes, ammonias, aldehydes/amines, Guanine, etc.: f(', Thioureas, thiazoles, thiurams, vulcanization accelerators such as L dithiocarbamates, xanthates, metal oxides, vulcanization accelerators such as fatty acids, amines, aldehydes, amines, Ketones, amines, phenols, imidazoles.

A composition can be prepared by adding sulfur-containing or sulfur-containing anti-aging agents, naphthenic or aromatic process oils, etc. to an extent that does not exceed 41%.

In particular, it is preferred that the composition of the present invention contains 1 to 30 M parts of process oil per 100 parts by weight of rubber.

The composition of the present invention has a low Mooney viscosity and therefore has a force of 11
The workability is excellent, and the Mloo of the vulcanizate is 30.
:'-9/al or higher and the pico wear index is 200 or more, preferably 210 or more and a4. 7. It has a large elastic modulus and excellent wear resistance, and can be used in place of known rubber chafer compositions as tire components for passenger cars, buses, trucks, airplanes, etc. (sidewalls, treads, etc.).
rims, beads, etc.).

Examples and comparative examples are shown below. In the description above, parts indicate parts by weight.

In addition, the Mooney viscosity MLl++ (10
0°C) was measured according to J I'S K 6300,
The tensile modulus, tensile strength and tear strength of the vulcanizate are determined according to JIS
K6301 has a pico wear index of A, ST'M 1) 2
22B.

Example 1 A natural rubber with a viscosity of 1X10' (
N, R) 100 parts, O, 1:H 1m-(3-methacryloyloxy-2-hydroxypropyl)N/-phenyl-p-7 enylenediamine [Knocklac G-1
．． (Manufactured by Shinko Ouchi) 1.0 part was added.

After washing for 1 minute, 6-nylon (product name: 103013,
Manufactured by Ube Industries, melting point 221°C, molecular weight 30,000)
50 parts were added and kneaded for 4 minutes. During this time, the temperature inside the mixer rose to 230°C, and the 6-nylon melted.

+4 & 7 in lie? Softening point 10 obtained by condensing phenol and paraformaltehyde using * as a catalyst
6℃, moisture content 0.12 Kurumachita, free phenol content I
jCO + ], 2.25 parts of novolac type phenol polymeraldehyde precondensation product (manufactured by Meiwa Kasei Co., Ltd., trade name 550PL), which is a powder crystal with triple fA of 1%, was added.
After kneading for 1141 min, hexamethylenetetramine 0°22
5 parts were added and kneaded for 2.5 minutes (During this time, the temperature in Banbury was 7°C). After the graft reaction, the mixture was dumped. Put the obtained kneaded material into the nozzle Y2η
111+, -2 Q++I#Iφ extruder (H
Oake Inc.) was extruded into a string shape at a die setting temperature of 235℃ once a month, and the extrudate was extruded into a string shape through a funnel installed vertically below the nozzle (1 screw in the funnel: 0℃ cooling water was supplied by a pump and a pipe. The supplied cooling water flows through the funnel and into a cooling water storage vessel located vertically below the funnel, from where it is returned to the funnel by means of pumps and pipes. ), then passed through a guide roll and was wound onto a bobbin at a draft ratio of 9 and a speed of 35 m/min. After drying this roll at room temperature for a day and night to remove adhering water.

Approximately 500 of these rolls are bundled into a sheet (thickness 2 + I1
m, width 150 rrum), and this sheet-like material was roll-rolled to about 10 times the size with a pair of rolling rolls with a roll gap of 0.2ηi+++ and a temperature of 60°C to obtain a reinforced rubber composition (1).
Masterbatch) (sample 1) was obtained.

The compounding ingredients shown in Table 1 except for the vulcanization accelerator and sulfur were kneaded in a Banbury machine set at 90°C and 77 rpm to obtain a mixed material, which is a composition for rubber chafer.
Next, this mixed wire material was kneaded with a vulcanization accelerator and sulfur on a 10-inch roll, and after being rolled out into a sheet, it was placed in a mold and vulcanized.

A vulcanizate was obtained. Vulcanization was performed at 145°C for 40 minutes. The results are summarized in Tables 1 and 2.

Fractionation, Grafting Rate Measurement The reinforced rubber composition 22, which had been i4+ with (J, example) - was added to 200 ml of benzene!1 part of room grime to dissolve the rubber content in the reinforced rubber composition. The slurry was centrifuged at room temperature to separate it into a solution portion and a precipitate portion.The above operation was repeated seven times for the precipitate portion, and the precipitate portion was dried to obtain nylon fibers.

This nylon fiber was dissolved in a mixed solvent of phenol and orthodichlorobenzene at a weight ratio of 1]4.
Analysis by nuclear magnetic resonance spectrum (NMR) (including t'y:
i 1 fluorotetramethylsilane) L, methyl and methylene groups originating from natural rubber from NMR cheat sheet, 6
- Methylene group adjacent to CO group due to nylon, N
For each peak of the methylene group adjacent to the H group and the other three methylene groups, the molar ratio of 6-nylon to natural rubber was determined by the cut area method, and the grafting ratio was calculated.

The shape of the nylon fibers described above was measured using a scanning microscope at a magnification of 1.0000 times for about 200 fibers.The fibers were extremely thin, short fibers with a circular cross section.Results are shown in Table 1.

Example 2 As a novolak, 141 parts of ε-caprolactam and 55.6 parts of paraformaldehyde with a purity of 81% were heated at 120°C.
The reaction was carried out for 5 hours to obtain an addition reaction solution containing an addition reaction product of ε-caprolactam and formaldehyde. Gradually drip the mixture into the ε-cuff.

After condensation reaction of rolactam with formaldehyde adduct tohisphenol F, 1 reaction mixture was distilled under reduced pressure (1
A reinforced rubber composition (
Sample 2. ), and a composition for a rubber chafer was obtained in the same manner as in Example 1, except that this reinforced rubber composition was used.

The results are summarized in Tables 1 and 2.

Example 3 As Novolank, 1412 parts of phenol and 1#L of concentrated
J, 1,041 parts of styrene was gradually added dropwise to a mixed solution with 40.3 parts of 5% hydrochloric acid, and the mixture was mixed at 130°C for 2 hours to styrenate the phenol.1 The reaction mixture was distilled under reduced pressure (180°C, 40i ), t, to obtain styrenated phenol, add 1.426 parts of formalin and 87 parts of sodium hydroxide at a concentration of 40 parts to the styrenated phenol, and mix at 80°C for 5 hours to dissolve formaldehyde into the styrenated phenol. was added (methylolated), 1653 parts of phenol and 123 parts of oxalic acid were added to the total amount of the addition reaction solution, and the methylolated styrenated phenol and phenol were condensed for 2 hours at 00°C for 1 reaction. The mixture was distilled under reduced pressure (1oo-+l
s.

'C+' 4: O+n, +++H, 2) A reinforced rubber composition was prepared in the same manner as in Example 1, except that the obtained styrenated phenol-phenol-formaldehyde initial condensate with a softening point of 73°C (ring and ball method) was used. (Sample 3) was obtained, and an Ii+1 composition for rubber chafer was obtained in the same manner as in Example 2, except that this reinforced rubber composition was used. The results are summarized in Tables 1 and 2.

Example 4 A reinforced rubber composition (sample 4) was prepared in the same manner as in Example 1, except that the amount of 6-nylon added to the natural rubber was changed to 100 parts.
Using this reinforced rubber composition, a rubber chafer composition having the formulation shown in Table 2 was obtained. The results are summarized in Tables 1 and 2.

Example 5 A reinforced rubber composition (Test Mine 15) was prepared in the same manner as in Example 1, except that the amount of 6-nylon added to the natural rubber was changed to 20 parts.
Using this reinforced rubber composition, a rubber chafer composition having the formulation shown in Table 2 was obtained. The results are summarized in Tables 1 and 2. Examples 6 to 9 A rubber chafer composition was prepared in the same manner as in Example 1, except that the blending ratio of each component was changed to the + shown in Table 2. It's a good deal. The results are summarized in Table 2.

Example 10. -13 Example except that the type of carbon black to be blended was changed]
It was carried out in the same way. The results are summarized in Table 2.

Comparative Example 1 A composition for a rubber chafer was obtained in the same manner as in Example 1, except that the reinforced rubber composition was not used and the proportions of each component were changed as shown in Table 2. The results are summarized in Table 2.

Table 1 Note that the fiber length of the nylon fibers embedded in the valley-reinforced rubber compound in test AS 1.1 and 5 is approximately 2 (t-
1-1) +3n: Polyphytagene (UB
EPOL-BR100.

(manufactured by Ube Industries, Ltd.) (l-1:2) r::q+ (, manufactured by styrene-butadiene copolymer rubber (r3BR-Sat Q OO+ Japan Synthetic Rubber Co., Ltd.)) (Note 33) Particle size Illμ, DBP
Oil absorption mz/10 (IN-]-Work O: S8 to T
tr 85〃〃l15 uII+-220
:]+;AF"n21〃'pH7〃14-:ro30'J
IA, F〃30rrrr1101'N' 4710
', FF Jr 38 #
'75 uN-550:FEF
〃 41 〃 〃 122
/r (Note 4) Other 1...II-1 mixture iJI+, lead white: 5 parts, stearic acid: 2 parts.

Anti-aging agent N-phenyl-N'-isoprobyl-p
-Phenylenediamine 1@IS.

Curing accelerator N-oxydiethylenebenzothiazyl-
2-sulfenamide 0.8 parts, sulfur 2.0
Department Patent Applicant Ube Industries Co., Ltd.

Claims (1)

[Claims] 100 parts by weight of vulcanizable rubber contains fine particles of a thermoplastic polymer having C) -CN H-no, in the polymer molecule /j5 (:', ;, fiber, -)~]00 Chongqiang - Chongyang -
A reinforced rubber composition (8) in which the polymer and the vulcanizable rubber are grafted via a phenol-formaldehyde-based resin first IJJ aM metal fitting at the interface between ), natural rubber, polyisoprene or a mixture of both (B), diene rubber (C) excluding natural rubber and polyisoprene, and carbon black (D), and the following (1) to (
A set of rubber chainers that satisfies the conditions of 1). (1) The amount of the thermoplastic polymer is 1-15 parts by weight per 100 parts by weight of the gold side of the rubber component. (1 [) Since it is rubber, the total amount of natural rubber in component (A) and component (B) is 20.
~50 weight class. (fit) The amount of bomb black is 50 to 70 parts by weight based on 100 parts by weight of the rubber components in total. (1v) The vulcanized product of the composition has a 100% modulus of 30
K2/cn1 or higher, AS'l'M D2228
The pico abrasion index specified in 200 or more.