JPS6023434A - Dust sealing material - Google Patents

Abstract

PURPOSE:To provide the titled substance composed mainly of chlorinated polyethylene, carbon black and glass powder, having excellent abrasion resistance, weather resistance, flexibility, oil resistance, flexural resistance, freeze resistance, and moldability, and suitable for a vehicle to check the leak of water. CONSTITUTION:The objective substance is produced by mixing and molding (A) 100pts.wt. of chlorinated polyethylene (preferably an amorphous chlorinated polyethylene having a chlorine content of 25-45wt%), (B) 5-50pts.wt. of carbon black (preferably thermal black or furnace black having a specific surface area of 600-1,200m<2>/g, (C) 5-100pts.wt. of glass powder, (D) 0.5-10.0pts.wt. of a detackifier (e.g. coumarone-indene resin), (E) 0.5-15.0pts.wt. of an agent to prevent the dehydrochlorination of vinyl chloride polymer (preferably dibasic lead phthalate, basic silicate, etc.) and (F) 0.5-20.0pts.wt. of an organic peroxide (preferably having a decomposition temperature of >=140 deg.C. USE:Bearing of a truck or an automobile having caterpillars.

Description

DETAILED DESCRIPTION OF THE INVENTION [I] Object of the Invention The present invention relates to a dust sealing material containing chlorinated polyethylene, carbon black and glass powder as main components. More specifically, (N chlorinated polyethylene, (B) carbon black, (C) glass powder, (D) tackifier,
(E) Vinyl chloride polymer dehydrochlorination prevention material and (
The present invention relates to a dust sealing material made of an organic peroxide, and the object thereof is to provide a dust sealing material with excellent wear resistance.

[■] Background of the Invention Prior to the invention, thermoplastic nidistomers have been used as lubricants, fillers, anti-aging agents, plasticizers, vulcanizing agents, vulcanization accelerators, vulcanization accelerating aids,
Additives such as crosslinking agents and crosslinking aids are added and heat treated.
Rubber elastic compositions obtained by crosslinking before vulcanization, that is, rubber products, are widely used in transportation vehicles that use caterpillars, safety and security heavy parts of automobiles, industrial products, and other parts. It is well-known that they greatly contribute to maintaining and improving the performance of cars, automobiles, and industrial products. Transport vehicles that use caterpillars,
Materials with even higher performance (higher properties) than the properties that are considered most important in automotive engineering, such as heat resistance, cold resistance, sealing resistance, abrasion resistance, water resistance, oil resistance, weather resistance, and bending resistance. It is requested. Thermoplastic elastomers with high performance in these properties (e.g., silicon-containing rubber, epichlorohydrin-based comb, urethane-based rubber, fluorine-containing comb) have high performance in terms of processability and cost. There's a problem. On the other hand, commonly used thermoplastic nidistomers have no problem in terms of price, but have poor heat resistance and weather resistance because they have double bonds. For this purpose, anti-aging agents, antioxidants, etc. are added, but the anti-aging agents and antioxidants tend to bleed, and all properties have their pros and cons, so it cannot always be said that they are satisfactory. moreover,
Problems with each commonly used thermoplastic elastomer will be discussed in detail.

Styrene-butadiene copolymer rubber (SBR) and acrylonitrile-butanoene copolymer rubber (NBR) have excellent oil resistance, cold resistance, and bending resistance, but they have double bonds in their structure. Even if a relatively large amount of anti-aging agent, antioxidant, etc., which has weather resistance and ozone resistance, is added to the product, the long-term retention is poor. Also, ethylene-
Propylene-diene terpolymer rubber (EPDM) has excellent cold resistance, bending resistance, and ozone resistance. However, it does not have excellent oil resistance, which is the most important physical property for dust sealing materials. Furthermore, chloroprene rubber (CR) exhibits excellent oil resistance, cold resistance, and bending resistance.

However, since SBR and NBR have double bonds, short-term weather resistance and ozone resistance can be improved by adding relatively large amounts of anti-aging agents. However, with long-term use, these characteristics deteriorate. Furthermore, chlorosulfonated polyethylene has excellent oil resistance, cold resistance, bending resistance, ozone resistance, and weather resistance. However, there is a problem in terms of cost.

[■] Structure of the Invention In light of the above, the present inventors have developed a rubber that is relatively low cost, improves the drawbacks of these commonly used thermoplastic nidistomers, and is suitable for dust sealing materials. As a result of various searches for obtaining an elastic composition, (A) chlorination, 10.0 parts by weight of 71.1 ethylene,
(B) Furnace black 5 to 50 parts by weight, (C)
Glass powder 5-100 parts by weight, 0) Tackifier 0
．． 5 to 10.0 parts by weight, (odor) dehydrochlorination inhibitor for vinyl chloride polymers (hereinafter referred to as "dehydrochlorination inhibitor") 0
．． A dust sealing material consisting of 5 to 15.0 parts by weight and (F) 0.1 to 20.0 parts by weight of an organic peroxide is not only relatively inexpensive, but also has the advantage of being a thermoplastic nitrogen oxide material that is commonly used as described above. The present invention was achieved based on the discovery that the drawbacks of the conventional method are greatly improved.

(IV) Effects of the Invention The dust sealing material obtained by the present invention is promising for the following uses.

(1) Dust sealing material for transport vehicles that use caterpillars, etc. (2) Dust sealing material for areas where the shaft of a car rotates (
3) Dust seal material for water leak prevention vehicles such as underwater cameras (4) Dust seal material for reciprocating industrial materials The dust seal material obtained by the invention exhibits an anchoring effect when used in combination with glass powder and a tackifier.

Therefore, even if a relatively large amount of glass powder is added, poor dispersion does not occur, making it an excellent dust sealing material. The dust sealing material obtained by the present invention has the following effects (characteristics):
demonstrate.

(1) Excellent weather resistance.

(2) Good wear resistance.

(3) Excellent flexibility.

(4) Good oil resistance (aromatic oil, aromatic oil).

(5) Excellent flexibility and cold resistance.

(6) Good dimensional accuracy.

(7) Good moldability and low shrinkage during molding.

[■] Detailed Description of the Invention (A) Chlorinated polyethylene The chlorinated polyethylene used in the present invention is prepared by chlorinating 4e-lyethylene powder or particles in an aqueous suspension, or by chlorinating polyethylene dissolved in an organic solvent. It is obtained by chlorination (preferably by chlorination in an aqueous suspension). Generally, amorphous or crystalline chlorination, whose chlorine content is 20-50% by weight, J Polyethylene, particularly amorphous chlorinated polyethylene having a chlorine content of 25 to 45% by weight, is preferred.

Said polyethylene is obtained by homopolymerizing ethylene or copolymerizing ethylene with at most 10% by weight of α-olefin (generally having at most 12 carbon atoms). Its density is generally 0.910~
It is 0.970.9z jin. In addition, its molecular weight is 50,000~
It is 700,000.

In producing the composition of the present invention, only chlorinated polyethylene may be used, but other types of polymeric substances that are miscible with chlorinated polyethylene may also be blended. Examples of the polymer materials include ethylene-zolopyrene-diene ternary copolymer copolymer (EPDM), natural rubber, chloroprene rubber, chlorosulfonated polyethylene rubber, and styrene-butadiene copolymer copolymer (SBR). ), acrylonitrile-butadiene copolymer comb (NBR)
, rubber-like materials such as urethane-based combs and butadiene homopolymer combs [generally, Mooney viscosity (
ML1+4) is 10 to 150]. In addition, other polymeric substances include the polyethylene, vinyl chloride resin containing vinyl chloride as a main component (degree of polymerization, 400 to 18
00), methyl methacrylate resins containing methyl methacrylate as a main component, and acrylonitrile-styrene copolymer resins. To these rubbery and resinous substances? Edited by Kambara et al., ``Synthetic Column Book'' (Asakura Shoten, published in 1962)
It is well known from books such as ``Publastic Ndobook'' edited by Murahashi et al. (published by Asakura Shoten, 1973).

When these polymeric substances are blended, the blending ratio is at most 50 parts by weight based on the chlorinated polyethylene.

(B) Carbon black Furthermore, the carbon black used in the present invention generally has a specific surface area that can be measured by low-temperature nitrogen adsorption method and i
The pore volume is 207180'Om2/g as measured by the BET method and 1.5 to 4. Or! ,,/9, and those having a specific surface area of 600 to 1200 m2/9 are particularly effective.

Examples of the carbon black include channel black, thermal black, acetylene black, and carbon black produced by a furnace black method. Regarding these carbon blacks, please refer to "Carbon Black Handbook" (published by Tosho Publishing Co., Ltd., published in 1972) edited by Cargan Black Association, "Paper Handbook" (edited by Rubber Digest Co., Ltd., and "Rubber Silastic Compounded Chemicals" (Rubber Digest Co., Ltd., published in 1978). Their manufacturing methods and physical properties are well known, such as from the above-mentioned ``Synthetic Rubber Handbook''. , ri (generally, the specific surface area is 6
00 to 1.200 m2/g) is not suitable because the conductivity is large and the modulus is high. Channel grains obtained by the channel method (generally with a specific surface area of 50 to 1.200 m/9) are used for special purposes, but because their pH is acidic, they are used in the present invention. It is not suitable as carbon fiber. In contrast, thermal black and furnace black obtained by the thermal method and furnace method have reinforcing properties, flexibility, abrasion resistance, heat resistance, oil resistance, and alkalinity (as Pl-1) against chlorinated polyethylene. Therefore, it is suitable because it can provide high properties with a relatively small amount of compounding.

(C) Glass powder The glass powder used in the present invention generally has a specific gravity of 2.10 to 270. In addition, the softening temperature is 5
00-900°C. Furthermore, the particle size is between 5 and 100 microns.

(F)) Tackifier Further, in the present invention, the tackifier is a tackifier that is generally used to improve the caking and dispersion properties of fillers or to increase adhesive properties. be. Typical examples of adhesion promoters include coumaron-indene resin produced by polymerizing coumaron, indene, styrene, etc. contained in coal tar, phenol/chillone resin, and petroleum hydrocarbons. Examples include resins and lonone derivatives. These tackifiers are listed in Section 1 of the above-mentioned ``Handbook of Rubber and Plastic Compounded Chemicals''.
The types, physical properties, etc. are described in detail on pages 29 to 144.

■) Dehydrochlorination inhibitor Furthermore, the dehydrochlorination inhibitor used in the present invention generally contains no-locaine atoms (
Polymers containing mainly chlorine atoms are widely used to prevent dehydrochlorination caused by heat or the like. The dehydrochlorination inhibitors are broadly classified into metal soaps, inorganic acid salt metal compounds, organic tin compounds, and pure organic compounds.

Among these, typical examples of metal soaps include metal salts of organic carboxylic acids having 1 to 10 carbon atoms (which may be substituted with at most 3 chlorine atoms). Such metals include lithium, magnesium, calcium, strontium, barium, cadmium, aluminum and lead.

Other metal soaps include lead salts of carboxylic acids such as tribasic maleic acid, dibasic phthalic acid and salicylic acid. In addition, examples of inorganic acid salts include alkylaryl cadmium sulfite, lead orthosilicate-silica glu coprecipitate, basic lead silicate, tribasic lead sulfate, basic lead sulfite, and dibasic lead phosphite. can give. Among metal oxides, magnesium oxide is preferably used. Further, organic tin compounds include dibutyl tin solaure-1, octyl tin compounds, trimethyltin compounds, dibutyl tin malate, sulfur-containing organotin compounds, stannane diol derivatives, and butyl tin compounds.
-C-tin-β-mercaptozolo gunoate. Examples of pure organic compounds include chelating agents [the general formula is shown in formula (■)] and epoxy compounds.

1 In formula (1), R, R and R may be the same or different, and are hydrocarbon groups having at most 20 carbon atoms.

Furthermore, other dehydrochlorination inhibitors include stearoylbenzoylmethane and balmitoylbenzoylmethane. It is written on the page. Among these dehydrochlorination inhibitors, inorganic acid salts, metal oxides and organic tin compounds are preferred, and inorganic acid salts and metal oxides are particularly preferred. In particular, dibasic lead phthalates, dibasic lead stearates, tribasic lead sulfates, basic silicates, magnesium oxide and lead oxide are preferred.

(About organic peroxide)Although there are no particular limitations on the organic peroxide used in the present invention, it is particularly desirable to have a decomposition temperature (temperature at which the half-life is 1 minute) of 120°C or higher, particularly 140°C.
The above are preferred.

Representative examples of suitable organic peroxides include 1,1-bis-
Ketosono 4-oxides such as tertiary-butylperoxy-3,3,5-1-methylcyclohexane, 2.5
-dimethylbexane-2; hydroperoxide such as 5-sobaidorobexane, 2,5-dimethyl-2
, 5-no-tertiary-butylno-P-oxyhexane, diacylno-oxides such as benzoyl peroxide, and soalkyl peroxides such as dicumyl/J-oxide.

Furthermore, polyfunctional substances such as triallyl isocyanurate and triallyl isocyanurate, which are commonly used as crosslinking aids in the rubber field, may be blended.

(G) Composition ratio (mixture ratio) 100 parts chlorinated, ]? The blending ratios of other composition components to polyethylene (other rubber-like substances and /-!, bamboo resin-like substances are also included if they are included) are as follows.

The blending ratio of carbon black is 5 to 50 parts by weight,
The amount is preferably 10 to 50 parts by weight, and preferably 10 to 40 parts by weight. If the blending ratio of carbon black to 100 parts by weight of chlorinated polyethylene is less than 5 parts by weight, a dust material with excellent reinforcing properties and abrasion resistance cannot be obtained. On the other hand, if it exceeds 50 parts by weight, moldability is poor and not only a good dust sealing material cannot be obtained, but also a material having appropriate flexibility cannot be obtained.

Furthermore, the composition ratio of the glass powder is 10 to 100 parts by weight, preferably 20 to 100 parts by weight;
70 parts by weight is preferred. If the composition ratio of glass powder to 100 parts by weight of chlorinated polyethylene is less than 10 parts by weight, a composition with good wear resistance cannot be obtained. On the other hand, 1
If the particle size exceeds 0.00, either the dispersibility of the glass powder is not good even if the above-mentioned adhesion promoter is used, or it is difficult to obtain a uniform composition, and the glass powder is difficult to obtain. Even if a composition is obtained, the flexibility is not good.

In addition, the composition ratio of the tackifier is 0.5 to 10.0 parts by weight, and preferably 0.5 to 7.0 parts by weight.
0 to 5.0 parts by weight is suitable. If the composition ratio of the adhesion promoter to 100 parts by weight of chlorinated polyethylene is less than 0.5 parts by weight, the dispersibility of the glass powder is not good. On the other hand, when more than 10.0 parts by weight is added, the surface hardness of the resulting product (dust sealing material) increases, but not only does the flexibility deteriorate, but the abrasion resistance also decreases.

The mixing ratio of Sara K and dehydrochlorination inhibitor is 1.0 to 15.
0 parts by weight is preferred, particularly 5.0 to 10.0 parts by weight.

The blending ratio of the organic peroxide is preferably 0.1 to 20.0 parts by weight, or 1.0 to 10.0 parts by weight.

Furthermore, if a crosslinking aid is used, the proportion used is at most 10.0 parts by weight.

If the blending ratio of the dehydrochlorination inhibitor to the chlorinated polyethylene is less than the lower limit, a dust sealing material with good stability cannot be obtained. On the other hand, even if the amount exceeds the upper limit, the stability will not be further improved, and in fact, they may form a bleed mark on the surface of the dust sealing material, which is not preferable. Furthermore, if the blending ratio of the organic peroxide is less than the lower limit, crosslinking will not proceed to completion and a good sealing material will not be obtained. On the other hand, if the upper limit is exceeded, crosslinking will proceed rapidly, making it difficult to obtain a product with a good shape, or it may become difficult to control crosslinking.

斡) Mixing method, molding method, etc. Although it is possible to obtain a composition for producing the dust sealing material of the present invention by uniformly blending the above-mentioned substances, it is also possible to obtain a composition for producing the dust sealing material of the present invention. Additives such as additives, plasticizers, oxygen, ozone, heat and light (ultraviolet) stabilizers, lubricants and colorants may be added depending on the intended use of the composition.

Furthermore, when manufacturing the composition of the present invention, a treated product obtained by pre-processing the glass powder and the tackifier may be used, or when the composition is manufactured without this treatment. May be added.

When producing the composition of the present invention, the blending (mixing) method is as follows: Mixing may be carried out using a mixer such as an open roll, a dry blender, a Banbury mixer, or a Negoo mixer commonly used in the art. good. Among these mixing methods, in order to obtain a more uniform composition, two or more of these mixing methods may be applied (for example, after mixing in advance with a dry blender, the mixture may be mixed using an open roll. How to mix).

The composition of the present invention may be molded into a dust seal using molding machines commonly used in the rubber industry, such as extrusion molding machines, injection molding machines, compression molding machines, and calender molding machines. In addition, a method of manufacturing a molded product (dust seal) while vulcanizing (crosslinking) by adding chlorinated polyethylene or the above-mentioned composition and vulcanizing (crosslinking) it in the rubber technology field, that is, a method of simultaneously proceeding vulcanization and molding. It may be formed into a desired shape using a molding machine such as an extrusion molding machine, an injection molding machine, a compression molding machine, or a calendar molding machine, which are used for molding into a desired shape.

However, in the field of comb technology, there is still no method for producing molded products using chlorinated polyethylene while vulcanizing (crosslinking) it by adding the above-mentioned composition, that is, a method in which vulcanization and molding proceed simultaneously. It may be applied and molded into a desired shape.

[VD Examples and Comparative Examples The present invention will now be explained in more detail with reference to Examples.

In addition, in the Examples and Comparative Examples, the oil resistance test was conducted using a JIS test tube set at a temperature of 120°C.
A sample for volume change rate measurement was immersed in S Temple 3 oil, and after being left for 3 days, the hardness (hereinafter referred to as rHs J) was measured to determine the change in Hs. Further, the rate of change in volume (hereinafter referred to as "ΔV") was measured using the Archimedes method. Furthermore, oil resistance and grease resistance tests were conducted using products manufactured by Mitsubishi Corporation (product name: F-mild, EP-4).
6β) and grease (trade name AP-2) under the same conditions as the oil resistance test. In addition, the abrasion resistance test was conducted using a paint abrasion tester with a load of 1.5 kg.
The amount of wear was measured on a country-by-country basis using Sand d--(AA-400) under the condition that the number of revolutions was 1000 revolutions.

In addition, the chlorinated polyethylene, carbon black, glass powder, tackifier,
The physical properties and types of the dehydrochlorination inhibitor, organic peroxide, and crosslinking aid are shown below.

[(4) Chlorinated polyethylene] Density is 0.941 g/cr as chlorinated polyethylene
Water-based n3 ethylene polymer (average molecular weight approximately 200,000)! @Chlorinated polyethylene obtained by chlorination using the turbidity method [chlorine content 40.2% by weight, amorphous,
hereinafter referred to as "r CPE"] and density is 0.93
Chlorinated polyethylene [chlorine content: 30.2% by weight] obtained by chlorinating an ethylene polymer (average molecular weight: about 170,000) of 6,j9/cnT by an aqueous suspension method.
, amorphous, hereinafter referred to as r CPE (B) J] was used.

[(B) Carbon black]

Still, carbon black, furnace black (
Showa era? Manufactured by Nodo Co., Ltd., product name Shogura, Ri
N-220, particle size 19-29 mm, specific area 1
1.1~128 m2/jq, hereinafter referred to as rcBJ)
I used

[(C) Glass powder] Furthermore, the glass powder has a specific gravity of 248 and an average particle size.
Glass powder (manufactured by Toshiba Balochii, trade name: Toshiba Glass Peas B-731, hereinafter referred to as "glass") having a diameter of 30 microns and a hardness (Mohs hardness) of 6.5 was used.

[(c) Tackifier]

As a tackifier, phenol formaldehyde resin (manufactured by Hitachi Chemical Co., Ltd., trade name Hitanol 1502,
Softening point 85-1.05℃, specific gravity 1.03-1.04,
(hereinafter referred to as r TACK J) was used.

[(odor dehydrochlorination inhibitor)]

Tribasic lead sulfate (hereinafter referred to as "tribase") was used as a dehydrochlorination inhibitor for vinyl chloride polymers.

[(F) Organic peroxide]

As the organic peroxide, dicumyl oxide (manufactured by NOF Corporation, trade name Percumil D, hereinafter referred to as "peroxide") was used.

[(G) Crosslinking aid]

Triallyl isocyanate (hereinafter referred to as "T") is used as a crosslinking aid.
AIC] was used.

Examples 1 to 5, Comparative Examples 1 to 8 100 parts by weight of chlorinated polyethylene (types are shown in Table 1). In addition, when using a mixture consisting of CPE (4) and CPE (B), the surface temperature is adjusted to
5.0 parts by weight of peroxide, 5.0 parts by weight of TAIC (as a crosslinking aid) and 10.0 parts by weight of tribase. [As a dehydrochlorination inhibitor for vinyl chloride polymers, but Comparative Examples 7 and 8 were not used] and CB (as carbon glaze), glass (as glass powder) and TACK (as tackifier) ( Table 1 shows the respective blending amounts).The mixture was thoroughly kneaded for 30 minutes using an open roll whose surface temperature was previously set at 50°C to form a sheet.

Each sheet thus obtained was heat pressed for 15 minutes at a temperature of 170°C and a pressure of 200 kg/cnr2, with an outer diameter of 70 mm, an inner diameter of 50 mm, and a thickness of 15 mm.
A ring-shaped dust seal for the throat was manufactured.

Each of the obtained dust seals was subjected to a wear resistance test, an oil resistance test, and a grease resistance test. The results are shown in Table 2. In addition, in this table, H
s is expressed as change (unit: points).

In Comparative Examples 7 and 8, dehydrochlorination occurred during the production of the dust seal, and a dust seal could not be obtained.

From the results of the above Examples and Comparative Examples, the dust seal material obtained by the present invention is not only excellent in volume change rate (ΔV) of oil resistance and grease resistance, but also has good wear resistance. This is obvious, and therefore, it is clear that it has a promising future application as a dust sealing material for transport vehicles using caterpillars as described above.

Patent applicant: Showa Denko Co., Ltd. Patent applicant: Akira Tofuji Agent: Patent attorney Sei Kikuchi

Claims (1)

[Scope of Claims] (5) Chlorinated polyethylene 100 parts by weight, (B) Carbon black 5-50 parts by weight, (C) Glass powder 5-100 parts by weight, (D) Adhesive agent 0.5-'
1 o, 0 parts by weight, (]0 vinyl chloride polymer dehydrochlorination inhibitor 0.5-]5.0 parts by weight, and (organic peroxide 0.1-20.0 parts by weight) 7-L material.