JPH0270734A - Rubber composition for waterproof sheet - Google Patents

Abstract

PURPOSE:To improve the adhesiveness, weathering resistance and heat resistance of a waterproof sheet by using a rubber prepared by hydrogenating a conjugated diene/aromatic vinyl compound random copolymer specified in the MW distribution and the vinyl bond content. CONSTITUTION:This rubber composition for waterproof sheets is prepared by using a hydrogenated diene polymer (ML1+4 at 100 deg.C of 5-150, desirably, 30-100) prepared by hydrogenating a random diene copolymer of a conjugated didene such as 1,3-butadiene with 5-50wt.%, desirably, 15-30wt.%, vinyl-aromatic compound such as styrene (of an MW distribution Mw/Mn<=10 and a vinyl bond content in the diene part of 10-80wt.%, desirably, 20-50wt.% and an Mw of 5,000-1,000,000) to a degree of hydrogenation >=80% as a rubber component.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention provides a random diene copolymer containing at least one conjugated diene and 5 to 50% by weight of a vinyl aromatic compound, which has a molecular weight distribution of Mw/Mn. is 10 or less, and the vinyl bond content of the diene part is 10 to 80%, and at least 80% of the olefinic unsaturated bonds in the polymer are hydrogenated. This invention relates to a waterproof sheet that uses a polymer as a rubber component and has good adhesiveness, weather resistance, and heat resistance.

[Prior Art] Generally, as a waterproof sheet mainly made of synthetic rubber, a blend system of butyl rubber/ethylene φ propylene rubber or a single system of ethylene φ propylene rubber is used. Adhesion of sheets to each other is an important step in the application of this waterproof sheet, and if the sheets are not properly adhered to each other, the sheets may peel off from each other, impairing the original purpose of waterproofing and potentially leading to water leakage accidents. be.

At present, neither ethylene-diluted propylene rubber nor butyl rubber/ethylene/propylene rubber blend compositions have sufficient adhesive properties. Solutions to these problems include adding tackifiers to the base rubber composition or blending polar substances, and on the other hand, roughening the surface of the tarpaulin sheet to increase the adhesive area and increase the adhesive strength. So-called puffing is commonly used to improve the quality of the skin, but at present no fundamental solution has been reached in either case.

[Problems to be Solved by the Invention] The present invention provides a random diene copolymer containing at least one conjugated diene and 5 to 50% by weight of a vinyl aromatic compound, which has a molecular weight distribution Mw/Mn of 10 or less, and Use a hydrogenated diene polymer in which at least 80% of the olefinic unsaturated bonds in the diene part are hydrogenated by hydrogenating a diene polymer having a vinyl bond content of 10 to 80% in the diene part. Accordingly, it is an object of the present invention to provide a waterproof sheet that has good adhesion, which is the problem mentioned above, and also has good weather resistance and heat resistance.

[Means for Solving the Problems] The present invention is a random diene copolymer containing a small amount (both 5 to 50% by weight of one type of conjugated diene and a vinyl aromatic compound), and having a molecular weight distribution Mw/Mn of 10 or less. , and a diene polymer having a vinyl bond content of 10 to 80% in the diene part is hydrogenated to obtain a hydrogenated diene polymer in which at least 80% of the olefinic unsaturated bonds in the polymer are hydrogenated. The present invention provides a rubber composition for a waterproof sheet, which is characterized in that it is used as a rubber component.

Examples of the hydrogenated diene polymer used in the present invention include hydrogenated rubber of a random diene copolymer of at least one conjugated diene and a vinyl aromatic compound.

Examples of the conjugated diene of such a conjugated diene-based polymer include conjugated dienes having 4 to about 12 carbon atoms in the -shell, and specific examples include 1°3-butadiene, isoprene, 2. 3-dimethyl-1,3-butadiene, 1
．． 3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexanediene, 4,5-diethyl-1,
Examples include 3-octadiene, 3-butyl-1,3-octadiene, and chloroprene. The conjugated diene is not particularly limited, but 1,3-butadiene and isoprene are particularly preferred, and elastomers such as polybutadiene, polyisoprene, and butadiene/isoprene copolymers are particularly preferred.

Further, specific examples of the vinyl aromatic compound used in the production of the copolymer of the conjugated diene and the vinyl aromatic compound include styrene, t-butylstyrene, α-methylstyrene, p-methylstyrene, and the like. In particular, styrene and α-methylstyrene are preferred. As specific examples of copolymers, butadiene/styrene copolymers, isoprene/styrene copolymers, butadiene/α-methylstyrene copolymers, etc. are most preferred since they provide highly hydrogenated rubber.

Such a copolymer is a random copolymer and has a vinyl aromatic compound content of 5 to 50% by weight, preferably 15 to 30%. If it is less than 5% by weight, it is difficult to obtain sufficient adhesive strength;
If the amount exceeds 50% by weight, the hydrogenated diene polymer will take on resinous properties and the object of the present invention will not be achieved.

Further, the vinyl bond of the conjugated diene unit accounts for 10 to 80% by weight, preferably 20 to 50% by weight of the entire conjugated diene unit. If it is less than 10% by weight, the hydrogenated diene polymer will have resinous properties and the object of the present invention cannot be achieved, and if it is more than 80% by weight, it will have a sufficient mechanical characteristic molecular weight of about 5,000 to about 1,000.
,000, and includes not only linear copolymers but also so-called branched, radial or star copolymers coupled with a coupling agent.

Specific examples of coupling agents include (dichloromethyl)
triclobisilane, (dichlorophenyl)trichlorosilane, 1,2-bis(trichlorosilyl)ethane, hexachlorodisilane, 1,2°3.4,7.7-hexachloro-6-methyldichlorosilyl-2-norbornene,
Examples include octachlorotrisiloxane and trichloromethyltrichlorosilane.

Furthermore, in living anionic polymerization, polymers whose ends are modified with polar groups and polymers whose polymers are modified with polar groups by other means are also included. Examples of the polar group to be modified include a hydroxyl group, a carboxyl group, an ester group, an isocyanate group, a urethane group, an amide group, a urea group, and a thiourethane group.

The diene polymer can be obtained, for example, by anionic living polymerization in a hydrocarbon solvent using an organolithium initiator. Further, the branched polymer can be obtained by adding a required amount of a trifunctional or more functional coupling agent at the end of the polymerization to perform a coupling reaction.

Ethers, tertiary amine compounds, alkoxides, phenoxides, and sulfonates of alkali metals such as sodium and potassium are used to control the amount of vinyl bonds such as 1.2-13,4-bonds.

As the organolithium initiator, n-butyllithium, 5
ec-butyllithium, tert-butyllithium, etc. are used. Hydrocarbon solvents include hexane, heptane, methylcyclopentane, cyclohexane, benzene, toluene, xylene, 2-methylbutene-1,2-
Methylbutene-2 and the like are used.

The polymerization may be carried out in a batch manner or in a continuous manner, and the polymerization temperature is usually in the range of 0 to 120°C and the polymerization time is in the range of 10 minutes to 3 hours. The coupling agent is a trifunctional or more functional coupling agent such as tetrachlorosilicon, butyltrichlorosilicon, tetrachlorotin, butyltrichlorotin, tetrachlorogermanium, bis(trichlorosilyl)ethane, divinylbenzene, adipic acid diester, epoxidized liquid polybutadiene. , epoxidized soybean oil, epoxidized linseed oil, tolylene diisocyanate, diphenylmethane diisocyanate, 1. Examples include 2,4-benzene triisocyanate.

A hydrogenated diene polymer is obtained by hydrogenating the diene polymer thus polymerized.

Mooney viscosity of hydrogenated diene polymer (ML1+4.10
0°C) is 5 to 150, preferably 30 to 100, from the viewpoint of kneading workability and mechanical properties.

The hydrogenation rate of olefinic unsaturated bonds in the hydrogenated diene polymer is 80% or more, preferably 85% or more. If the hydrogenation rate is less than 80%, sufficient weather resistance and heat resistance cannot be obtained.

In the hydrogenation reaction, the above conjugated diene polymer is dissolved in a hydrocarbon solvent, and the hydrogenation reaction is carried out at 20 to 150°C and 1 kg/cJ to 100 k.
It is carried out in the presence of a hydrogenation catalyst under pressurized hydrogen of g/CI#.

Hydrogenation catalysts include catalysts in which precious metals such as palladium, ruthenium, rhodium, and platinum are supported on silica, carbon, diatomaceous earth, etc., complex catalysts such as rhodium, ruthenium, and platinum, and organic carboxylic acids and organic aluminum such as cobalt and nickel. or a catalyst consisting of organolithium,
Titanium compounds such as dicyclopentadienyl titanium dichloride, dicyclopentadienyl diphenyl titanium, dicyclopentajenyl titanium ditolyl, dicyclopentadienyl titanium dibenzyl, lithium, aluminum,
A hydrogenation catalyst consisting of an organometallic compound consisting of magnesium is used.

In addition, the rubber composition for a waterproof sheet of the present invention may optionally contain other diene rubbers such as styrene-butadiene rubber (SBR) and isoprene rubber (IR), that is, ethylene-α-olefin-(diene) rubber ( EP (D
)M), ordinary polymers such as butyl rubber, acrylic rubber, epichlorohydrin rubber, and various commonly used compounding agents can be added.

Among the compounding agents, examples of reinforcing fillers and extenders include carbon black, fumed silica, wet silica,
Fine quartz powder, diatomaceous earth, zinc white, basic magnesium carbonate, activated calcium carbonate, magnesium silicate, aluminum silicon, titanium dioxide, talc, mica powder, aluminum sulfate, calcium sulfate, barium sulfate, asbestos, graphite, wollastonite , molybdenum disulfide, oxygen fibers, aramid fibers, various whiskers, glass fibers, organic reinforcing agents, and organic fillers.

Processing aids include, for example, metal oxides, amines, fatty acids and their derivatives; softeners include, for example, lubricating oils, process oils, coal tar, castor oil, and calcium stearate; anti-aging agents include, for example, phenylene diamines. , phosphates, quinolines, cresols, phenols, dithiocarbamate metal salts; examples of heat-resistant agents that can be used include iron oxide, cerium oxide, potassium hydroxide, iron naphthenate, and potassium naphthenate.

Other scorch inhibitors, tackifiers, etc. can be added as desired.

Vulcanizing agents include sulfur, dipentamethylenethiuram, sulfur compounds such as tetrasulfide, dicumyl peroxide, 1,1'-di(t-butylperoxy)-3,
Peroxides such as 3,5-)limethyl dichlorohexane, di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, p-quinonedioxime, p, Oxime compounds such as p'dibenzoylquinone dioxime can be used alone or in combination.

As the vulcanization accelerator, N-cyclohexyl-2-benzothiazole-sulfenamide, N-oxydiethylene-2-benzothiazole-sulfenamide, N,N-
Diisopropyl-2-benzothiazolesulfenamide, 2-mercaptobenzothiazole, 2-(2,4
-dinitrophenyl)mercaptobenzothiazole, 2
-(2゜6-danityl-4-morpholinothio), benzothiazole, penzothiazyl disulfide and other thiazoles; diphenylguanidine, triphenylguanidine, di-ortho-tolylguanidine, ortho-tolyl piguanide, diphenyl Guanidine type such as guanidine phthalate; acetaldehyde-aniline reaction product; aldehyde amine such as butyraldehyde-aniline condensate, hexamethylenetetramine, acetaldehyde ammonia, or aldehyde-ammonia type; 2-
Imidacillins such as mercaptoimidazoline; thiocarbanilide, diethylthiourea, dibutylthiourea,
Thiourea types such as trimethylruthiourea and di-orthotolylthiourea; thiuram types such as tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, and dipentamethylenethiuram tetrasulfide; zinc dimethyldithiocarbamate;
dithiocarbamate salts such as zinc diethylthiocarbamate, zinc di-n-butyldithiocarbamate, zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate, tellurium diethyldithiocarbamate; Examples include xanthate systems such as zinc dibutylxanthate, and mixtures thereof. These vulcanization accelerators have a rubber component of 10
It is usually used in a proportion of 0.1 to 20 parts by weight, preferably 0.2 to 10 parts by weight.

[Example] Hereinafter, the present invention will be further explained with reference to Examples, and various measurements were made according to the following methods.

The method for measuring the hydrogenated rubber used in the present invention was as follows. That is, the bound styrene content was determined from an infrared calibration curve based on the absorption of phenyl groups at 699 cm-'. The amount of vinyl bond was determined by an infrared method (Morello method). The molecular weight, total molecular distribution, and coupling efficiency (C/E) were determined from gel permeation chromatography (GPC). In addition, the hydrogenation rate was determined using ethylene tetrachloride as a solvent.
It was calculated from the spectral decrease of the unsaturated bond in the 100 MHz IH-NMR spectrum measured at 15% concentration.

Tensile test, aging test, ozone deterioration test is JISK630
Compliant with 1. In the adhesion test, a chloroprene rubber solvent-based adhesive is applied to the surfaces of two vulcanized rubber sheets, and after drying for 10 minutes, the two sheets are pasted together and pressed together with a roll. A peel test was performed one week later.

[Reference Example] Next, the method for producing the hydrogenated diene polymer used in the present invention will be explained in more detail. The ratio (parts by weight) based on 100 parts by weight of the polymer is shown below in units of PHR.

Sample 1 (1) After charging 2.500 g of degassed and dehydrated cyclohexane, 150 g of styrene, and 350 g of 1°3-butadiene into a 5fi autoclave, 2.5 g of tetrahydrofuran was added.
0.34 g of g5n-butyllithium was added to carry out polymerization. Temperature-rising polymerization was carried out at a polymerization temperature of 30 to 80°C. After the conversion rate was almost 100%, 0.14% of 5iC14 was added.
g added.

Then, 2,6-tert-butylcatechol was added and the solvent was removed by steam stripping.
A polymer was obtained by drying with a heated roll at ℃. The styrene-butadiene copolymer thus obtained has a vinyl bond content of 20
%, the styrene content was 15% by weight, and the branched polymer having three or more branches was 40% by weight. According to GPC measurement, the average molecular weight is 3
2°000, and Mw/Mn was 1.5.

(2) The conjugated diene polymer polymerized in (1)
The mixture was charged into an autoclave and made into a 15% cyclohexane solution. After purging the system with nitrogen, a catalyst solution containing nickel naphthenate, n-butyl lithium, and tetrahydrofuran (mole ratio) of 1:8:20 (mole ratio) prepared in advance in a separate container was added as nickel to 2.000 moles of the olefin portion. 1
I prepared it to be mole. Thereafter, hydrogen was introduced into the reaction system, and a hydrogenation reaction was carried out at 70°C. After controlling the hydrogenation rate based on the amount of hydrogen absorbed and consumed, the hydrogen in the system was replaced with nitrogen, and the anti-aging agent 2,6-di-tert-butyl para-cresol was added by IPIIR. After repeated decontamination and coagulation, roll drying was performed by a conventional method to obtain a hydrogenated diene copolymer used in Example 1 with a hydrogenation rate of 85%.

Sample 2 A styrene-butadiene copolymer having a vinyl bond amount of 40% and a styrene content of 15% by weight was obtained in the same manner as in (1) of Sample 1 except that the coupling reaction was not performed. This was carried out in the same manner as in (2) of Sample 1 to obtain a hydrogenated diene copolymer used in Example 2 with a hydrogenation rate of 95%.

Hereinafter, Examples 3 to 6 and Comparative Example 1 shown in Table 1 will be described in the same manner.
Hydrogenated diene polymer samples 3 to 8 used in Examples 1 to 2 were obtained. Furthermore, the ethylene-propylene terpolymer and isobutylene-isoprene rubber used in Comparative Examples 3 and 4 are also listed in Table 1 with Mooney viscosities.

The following blank Examples 1 to 6 and Comparative Examples 1 to 4 were sequentially charged into a BR type Banbury mixer and kneaded according to the formulations shown in Table 2 (excluding the vulcanizing agent). The rubber composition was discharged when it became uniform.

Next, the rubber composition thus obtained was wound around an open roll, and the vulcanizing agent shown in Table 2 was added and kneaded. Next, take out the kneaded material in a sheet form from the open roll,
The vulcanizate was heated under pressure for a predetermined period of time in a 160°C steam vulcanization press, and the physical properties of this vulcanizate were measured.

The measurement results are summarized in Table 3.

Margin below [Effect of the invention] Compared to the comparative example, the rubber composition for waterproof sheets of the present invention has Adhesion as shown in the examples; Weatherability, Heat-resistant October 1986 2Q day It has excellent characteristics.

Claims (1)

[Claims] At least one conjugated diene and a vinyl aromatic compound 5~
A 50% by weight random diene copolymer having a molecular weight distribution Mw/Mn of 10 or less and a vinyl bond content of 10 to 80% in the diene part is hydrogenated to produce the polymer. A rubber composition for a waterproof sheet, characterized in that a hydrogenated diene polymer in which at least 80% of the combined olefinic unsaturated bonds are hydrogenated is used as a rubber component.