JP2000007840A - Rubber sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rubber sheet capable of expecting a strong adhesive strength even by roller pressurization used in an execution site and readily performing bonding operations by adding a specific resin and a rubber-modified asphalt to a rubber composition having a specified composition. SOLUTION: This rubber sheet is obtained by molding a composition prepared by adding (B) (i) a polyethylene-based resin (preferably an ethylene vinyl acetate vinyl two-component copolymer), (ii) a liquid epoxy resin, (iii) an alkylphenol resin and (iv) a rubber-modified asphalt to (A) a rubber composition comprising a rubber (preferably an ethylene-propylene-based rubber), a vulcanizing agent, an auxiliary, a reinforcing agent and other additives, kneading the resultant mixture and molding the resultant composition into a sheetlike form. The amounts of the compounded components based on 100 pts.wt. of the component A are preferably 15-30 pts.wt. of the component (i), 2.0-6.0 pts.wt. of the component (ii), 0.2-1.8 pts.wt. of the component (iii) and 1.0-5.0 pts.wt. of the component (iv). Thereby, the resultant rubber sheet is excellent in thermal weldability through a molten rubber asphalt and adhesive strength, capable of readily performing bonding operations and suitably usable as a waterproof sheet, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber sheet used as a waterproof sheet or roofing for buildings and other structures, or as a grass sheet, and melts the rubber sheet according to the size and shape of the construction site. Adhesion through asphalt facilitates the bonding operation when joining vertically and horizontally, and enables the adhesion to be enhanced.

[0002]

2. Description of the Related Art It is known to use a rubber sheet for a waterproof sheet, a roofing sheet, a grass sheet and the like.
Since the size of the rubber sheet at the time of molding and vulcanization is much smaller than the width of the construction site, it was necessary to add a large number of rubber sheets vertically and horizontally at the construction site. For this reason, conventionally, a large number of rubber sheets are spread over the construction site, and the edges are overlapped, and adhesives such as a solvent-based adhesive, a naturally vulcanized rubber-based adhesive, or a heat-fusible adhesive made of a thermoplastic resin are used. It was glued. Therefore, conventionally, a troublesome operation of applying an adhesive to a rubber sheet at a construction site was required.

In order to solve this problem, rubber is used as a vulcanizing agent,
When kneading with auxiliaries, reinforcing agents and other additives, compound a polyolefin-based resin, vulcanize after forming into a sheet, and knead rubber with vulcanizing agents, auxiliaries, reinforcing agents and other additives. And then vulcanizing under pressure to integrate the rubber sheet with the polyolefin resin film (Japanese Patent Application Laid-Open Nos. 9-132676 and 9-132676). No. 9-143278). In addition, when joining these rubber sheets, it is proposed that molten rubber asphalt be interposed between the rubber sheets in order to prevent separation or water leakage even if sand, dust or other foreign matter is mixed between the rubber sheets. (See JP-A-10-88074).

[0004]

However, conventionally, the adhesion of the rubber sheet has been dependent on the fusion based on the thermoplasticity of the polyolefin resin contained in the rubber sheet. When the molten rubber asphalt is poured between the upper and lower rubber sheets of the overlapped portion, and pressed and joined by a running roller from above the upper rubber sheet, the molten rubber asphalt is placed between the two rubber sheets. There was a problem that a sufficient adhesive strength could not be obtained as compared with the case where heating was performed under pressure using a press machine.

According to the present invention, when rubber sheets are bonded to each other via molten rubber asphalt, a strong bonding force can be obtained even by pressing a roller used in a construction site, and the bonding operation is easy and practical rubber A sheet is provided.

[0006]

According to the first aspect of the present invention, a rubber composition comprising a rubber, a vulcanizing agent, an auxiliary agent, a reinforcing agent and other additives is formed into a sheet and vulcanized. The obtained rubber sheet is characterized in that a polyethylene resin, a liquid epoxy resin, an alkylphenol resin and a rubber modified asphalt are added and kneaded to the rubber composition.

That is, the present invention provides a conventional rubber composition comprising a rubber, a vulcanizing agent, an auxiliary agent, a reinforcing agent and other additives, together with a conventional polyethylene resin, a liquid epoxy resin, an alkylphenol resin and a rubber-modified asphalt. It is to be added. As a result, after forming into a sheet and vulcanizing, when the obtained rubber sheets are overlapped with a molten rubber asphalt layer interposed therebetween, a polyethylene resin and a liquid epoxy resin are formed at the interface between the rubber sheet and the molten rubber asphalt layer. Are formed and the adhesive strength is increased.
Moreover, since the rubber sheet contains the same rubber-modified asphalt as that of the molten rubber asphalt layer, the adhesive strength between the rubber sheet and the molten rubber asphalt layer is further improved. The rubber elasticity of the rubber sheet is hardly lost. Even when sand, dust, and other foreign substances are mixed between the rubber sheets, these foreign substances are buried in the rubber asphalt layer, so that a defective bonding portion does not occur.

The rubber used in the present invention is a conventional rubber used for waterproofing and weeding, and may be any rubber which can be mixed with a polyethylene resin. Particularly, ethylene propylene rubber and isobutylene isoprene rubber And a rubber containing at least one of halogenated isobutylene isoprene rubber as a main component is preferable. That is, any one of these rubbers can be used alone, or two or more can be mixed, or one or more rubber can be mixed with another rubber. However, when mixed with another rubber, the mixing ratio of the other rubber is preferably 40% or less of the total amount of rubber, and when the other rubber exceeds 40%, the weather resistance becomes insufficient.

The polyethylene resin used in the present invention is preferably a polyethylene modified with a functional group reactive to an epoxy group (excluding maleic anhydride) or a copolymer thereof. Examples thereof include a vinyl acetate binary copolymer, an ethylene glycidyl methacrylate binary copolymer, an ethylene glycidyl methacrylate vinyl acetate ternary copolymer, and an ethylene glycidyl methacrylate methyl acrylate ternary copolymer.
Particularly, an ethylene-vinyl acetate binary copolymer is preferable because it has excellent adhesive strength and can be obtained at low cost.

As the liquid epoxy resin used in the present invention, bisphenol A type epoxy resin, bisphenol F type epoxy resin, polyfunctional epoxy resin, glycidyl ester type epoxy resin, biphenyl type epoxy resin, etc. can be used. The bisphenol A type epoxy resin is particularly preferable because of its excellent versatility. The epoxy equivalent is preferably from 160 to 270. If the epoxy equivalent is outside this range, the adhesiveness becomes insufficient.

As the alkylphenol resin used in the present invention, those containing hexa are preferable from the viewpoint of adhesiveness, and phenol formaldehyde resins are particularly preferable from the viewpoint of excellent versatility.

The rubber-modified asphalt used in the present invention is an ordinary rubber-modified asphalt obtained by adding about 2 to 10% by weight of a rubber such as IIR or SBR or a resin such as SBS to asphalt and mixing them.

The amounts of the above-mentioned polyethylene resin, liquid epoxy resin, alkylphenol resin and rubber-modified asphalt are 15 to 30 parts by weight and 2.0 to 6.0 parts by weight, respectively, based on 100 parts by weight of the rubber composition. , 0.2
-1.8 parts by weight and 1.0-5.0 parts by weight are preferred, and if any of the polyethylene resin, liquid epoxy resin or alkylphenol resin is out of the above range,
Adhesive strength becomes insufficient. If the amount of the rubber-modified asphalt is less than 1.0 part by weight, there is no effect.
If it exceeds 0 parts by weight, foaming occurs during vulcanization.

The rubber, polyethylene resin, liquid epoxy resin, alkylphenol resin and rubber-modified asphalt described above can be used together with any vulcanizing agent such as sulfur or organic peroxide, an auxiliary agent, a reinforcing agent and other additives in a conventional manner. , Are formed into a sheet, and vulcanized. The obtained rubber sheet can be used alone, of course, and a reinforcing fiber sheet (for example,
(Woven fabric, knitted fabric, non-woven fabric) can be laminated and used as a composite sheet. In this case, the fiber sheet is laminated on the unvulcanized rubber sheet and integrated by vulcanization.

The obtained two rubber sheets are spread on the construction site so that the edges overlap, and the molten rubber is spread along the edge of the lower rubber sheet in a state where the upper rubber sheet of the overlapping portion is raised. The asphalt is allowed to flow down, and then the upper rubber sheet is overlaid, pressure is applied by a roller from above, and the edges of the two rubber sheets are brought into close contact with each other via a rubber asphalt layer therebetween, and natural cooling is performed. The overlap width of the two rubber sheets is preferably 40 to 50 mm. Further, the applied thickness of the molten rubber asphalt is 1 to 2 mm (the applied amount is 1200 to 2 mm).
400 g / m ² ) is preferable. When the coating thickness (coating amount) is small, a non-adhered portion is formed and water leakage easily occurs. On the contrary, when the coating thickness is too large, misalignment tends to occur and it is uneconomical.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A rubber composition 10 comprising EPDM, sulfur, auxiliaries, carbon black and other additives
1 part by weight of ethylene vinyl acetate binary copolymer
5 to 30 parts by weight, 2.0 to 6.0 parts by weight of liquid epoxy resin, 0.2 to 1.8 parts by weight of alkylphenol resin, and 1.0 to 5.0 parts by weight of rubber-modified asphalt, After kneading, the sheet is formed into a sheet having a thickness of about 2 mm, and then a pressing machine (temperature: 164 ° C., pressing pressure: 20 kgf / cm)
² ) Press for 20 minutes to obtain a vulcanized rubber sheet.

The obtained two rubber sheets are overlapped and arranged so that the edge thereof has a width of about 40 to 50 mm and the one back surface is in contact with the other back surface. The sheet is raised, and molten rubber asphalt having a temperature of 180 to 200 ° C. is flowed down along the edge of the lower rubber sheet to form a rubber asphalt layer having a thickness of 1 to 2 mm,
Thereafter, the upper rubber sheets are stacked, and the two rubber sheets are connected while applying a pressure of 1 to 2 kgf / cm ² with a roller from above.

The above EPDM may be replaced by IIR, halogenated IIR or a mixture of two or more thereof. Further, the ethylene-vinyl acetate binary copolymer,
It can be substituted with any of ethylene glycidyl methacrylate binary copolymer, ethylene glycidyl methacrylate vinyl acetate terpolymer or ethylene glycidyl methacrylate methyl acrylate terpolymer.

[0019]

EXAMPLE A rubber sheet was prepared using various rubbers and resins, and the rubber sheet was coated with molten asphalt and subjected to a peeling test.

The following rubber was used. EPDM (A): Idemitsu DSM Co., Ltd., trade name "Keltan 578" EPDM (B): manufactured by Mitsui Petrochemical Co., Ltd., trade name "Mitsui EP
T1070 "IIR: manufactured by Nippon Synthetic Rubber Co., Ltd., trade name" JSR butyl 26 "
8 "

Using the above rubber, three kinds of compounds shown in Table 1 below were prepared. In the table, “char coal” indicates “calcium carbonate”, and “process oil” indicates “paraffin-based process oil”. The unit is parts by weight.

Table 1 Formulation A Formulation B Formulation C EPDM (A) 100--EPDM (B)-30-IIR-70 100 Zinc white 5.55 Stearic acid 11 1 charcoal (light) 49.5 58.5 58.5 charcoal ( Heavy) 10 10 10 MAF black 55 60 60 Process oil 30 20 20 Sulfur 1.5 22 CBS 2.5--TMTD 1.5--Zn MDC 2.5--MBTS 1.5 1.5 1.5 Te EDC-2 2

The following resins A to D were used as the polyethylene resin. Resin A: Ethylene vinyl acetate binary copolymer (melting point 63
C., Sumitomo Chemical Co., Ltd., trade name "Smitate MB-11") Resin B: ethylene glycidyl methacrylate binary copolymer (melting point 105 ° C., Sumitomo Chemical Co., Ltd., trade name "Bond First 2C") Resin C: ethylene glycidyl Methacrylate vinyl acetate terpolymer (melting point 98 ° C .: manufactured by Sumitomo Chemical Co., Ltd., trade name “Bond First 2A”) Resin: ethylene glycidyl methacrylate acrylate terpolymer (melting point 52 ° C., manufactured by Sumitomo Chemical Co., Ltd.) Product name “Bond First 7M”)

The following EPR is used as a liquid epoxy resin:
As the alkylphenol resin (phenol formaldehyde resin), the following PFR (a) to PFR
(C) was used respectively. EPR: liquid epoxy resin (manufactured by Yuka Shell Epoxy Co., Ltd.
PFR (a): Phenol formaldehyde resin A (Sumitomo Durez, trade name "Sumilite Resin PR126")
87 ") PFR (b): phenol formaldehyde resin B (trade name" Sumilite Resin PR531 "manufactured by Sumitomo Durez Co., Ltd.)
95 ") PFR (c): Phenol formaldehyde resin C (Sumitomo Durez, trade name" Sumilite Resin PR703 ")
1A ")

As the rubber-modified asphalt, a rubber-modified asphalt (trade name “Ecophalt K-1”) manufactured by Nippon Oil Co., Ltd. in which SBR was mixed into asphalt was used.

In the rubber compositions of the above-mentioned Compounds A to C, the above resins A to D as polyethylene resins, the above EPR as liquid epoxy resin, the above PFRs (a) to (c) as alkylphenol resin, and The above rubber-modified asphalt (hereinafter, abbreviated as rubber asphalt) is blended in various weight ratios, and from 3.936 to 3.981 per batch.
7kg each 14 inch roll (roll temperature 60 ~ 110
C.), and a rubber sheet (width 450 mm, thickness 2.0 ± 0.1 mm) was dispensed with a 14-inch roll at a temperature of 60 to 70 ° C.

The unvulcanized rubber sheet is 400 mm on a side.
Into a test piece, placed on a 2mm-thick duralumin plate, 1.8mm thick, inner dimension 400mm
And put the same duralumin plate on top of it and sandwich it between the upper and lower hot plates of the press machine.
Vulcanization was performed by hot pressing at 64 ° C. under a pressure of 20 kgf / cm ² for 20 minutes.

The obtained vulcanized rubber sheet was cut into a rectangle having a length of 350 mm and a width of 300 mm, and was melted at 190 ° C. with molten rubber asphalt (trade name “Ecophalt K-
1 ") was coated to a thickness of about 2 mm and cooled at room temperature for 24 hours. Next, it is cut into a rectangular shape having a width of 25 mm and a length of 250 mm, and a cloth sticking tape (No. 750, manufactured by Nitto Denko Corporation) is stuck on the surface of the rubber asphalt layer, cooled to -40 ° C. After making a peeling opening at one end and returning to room temperature, a tensile tester (Technograph TG-1KN, manufactured by Minebea Co., Ltd.) was used as a measuring device at a temperature of 15 ° C. and a tensile speed of 10
A peeling test was performed by a 180 mm peeling method at 00 mm / min.

In the above-mentioned peeling test, the adhesive strength of the rubber asphalt layer which was broken was evaluated as ○, the partially peeled rubber was evaluated as △, and the whole surface was evaluated as ×. In addition, the workability was evaluated as 粘着 when there was neither stickiness nor settling at the time of kneading and during dispensing, and as x when there was excessive stickiness or settling. Regarding foaming at the time of vulcanization, those that did not foam at all during the vulcanization of the rubber sheet were rated as ○, those that slightly foamed were rated as Δ, and those that foamed were rated as x.

The results are shown in Tables 2 to 7 below together with the compounding ratio (unit: parts by weight) of the rubber sheet. In the table, "PE" indicates "polyethylene resin".

Table 2 Sample No. 1 2 3 4 5 6 7 8 9 Type of rubber compound A A A A A A A A A A Type of PE II I II I I II I Amount (parts) 17 17 13 17 28 28 28 28 33 EPR compounding amount (parts) 5.5 5.5 5.5 5.5 2.5 2.5 1.5 2.5 2.5 PFR type aa aaa aa aa Same compounding amount (parts) 1.6 1.6 1.6 2.1 0.3 0.3 0.3 0.1 0.3 Rubber compounding Amount (parts) 4.5 6.0 4.5 4.5 1.5 0.5 1.5 1.5 1.5 Adhesive strength ○ ○ △ △ ○ △ △ △ ○ Workability ○ ○ ○ ○ ○ ○ ○ ○ × Foaming during vulcanization ○ △ ○ ○ ○ ○ ○ ○ ○

Table 3 Sample No. 10 11 12 13 Type of rubber compound A A A A Type of PE Rohany Same compounding amount (part) 23 23 23 23 EPR compounding amount (part) 4.0 4.0 4.0 4.0 PFR type aaab Amount (parts) 1.0 1.0 1.0 1.0 Amount of rubber ass (parts) 3.0 3.0 3.0 3.0 Adhesive strength ○ ○ ○ ○ Processability ○ ○ ○ ○ Foaming during vulcanization ○ ○ ○ ○

Table 4 Sample No. 14 15 16 17 18 19 Type of rubber compound A A A A A A PE Type II I II I Amount (parts) 23 23 23 23 23 23 EPR Amount (parts) 4.0-4.0 4.0-4.0 Type of PFR c---aa Same blending amount (parts) 1.0---1.0 1.0 Rubber assembling amount (parts) 3.0--3.0 3.0-Adhesive strength ○ × × × × △ Processability ○ ○ ○ ○ ○ ○ Foaming during vulcanization ○ ○ ○ ○ ○ ○

Table 5 Sample No. 20 21 22 23 Type of rubber compound Type of CC C C PE Type II Good Compound amount (parts) 17 17 13 17 EPR compound amount (parts) 5.5 5.5 5.5 5.5 Type of PFR a a a a Same compounding amount (part) 1.6 1.6 1.6 2.1 Rubber ass compounding amount (part) 4.5 6.0 4.5 4.5 Adhesive strength ○ ○ △ △ Processability ○ ○ ○ ○ Foaming during vulcanization ○ △ ○ ○

Table 6 Sample No. 24 25 26 27 28 Type of rubber compounding Type of CCC CC CPE Type I II II Compounding amount (parts) 28 28 28 28 33 EPR compounding amount (parts) 2.5 2.5 1.5 2.5 2.5 PFR type aaaaa Same blending amount (parts) 0.3 0.3 0.3 0.1 0.3 Rubber assembling amount (parts) 1.5 0.5 1.5 1.5 1.5 Adhesive strength ○ △ △ △ ○ Workability ○ ○ ○ ○ × Foaming during vulcanization ○ ○ ○ ○ ○

Table 7 Sample No. 29 30 31 32 33 34 Type of rubber compounding BBBBBBPE Type of PE II I II II Compounding amount (parts) 17 13 28 28 28 28 EPR compounding amount (parts) 5.5 5.5 2.5 2.5 1.5 2.5 PFR type aa aaaa a Same amount (parts) 1.6 1.6 0.3 0.3 0.3 0.1 Rubber ass compounding amount (parts) 4.5 4.5 1.5 0.5 1.5.1.5 Adhesive strength ○ △ ○ △ △ △ Processability ○ ○ ○ ○ ○ ○ Foaming during vulcanization ○ ○ ○ ○ ○ ○

As is clear from Tables 2 to 7, samples 1, 5, 10, 11, 12, 13, 14, 20, 24,
29 and 31 are each a polyethylene resin (PE);
Since appropriate amounts of the liquid epoxy resin (EPR), the alkylphenol resin (EPF) and the rubber ass were mixed, the adhesive strength, processability and foaming during the process were all good. On the other hand, samples 2, 3, 4, 6, 7, 8,
9, 21, 22, 23, 25, 26, 27, 28, 3
0, 32, 33, and 34, all of the above PE, EPR, EPF and rubber ass are compounded, but at least any one compounding amount is out of an appropriate range, so that the adhesive strength, processability, foaming during processing. Either is slightly inferior, and sample 1
5, 16, 17, 18, and 19 correspond to the PE, EPR, E
Since either PF or rubber ass was not incorporated at all, the adhesive strength was particularly insufficient.

[0038]

As described above, the rubber sheet according to claim 1 is obtained by adding a liquid epoxy resin, an alkylphenol resin and a rubber-modified asphalt to a rubber together with a thermoplastic polyethylene resin. Excellent heat-sealing properties, excellent adhesive strength compared to conventional rubber sheets that do not use the above-mentioned liquid epoxy resin, alkylphenol resin and rubber-modified asphalt, easy bonding work, waterproof sheet and roofing, It can be suitably used as a grass sheet. And
The rubber sheet according to claims 2 and 3 is easy to manufacture,
The rubber sheet according to claim 4 has particularly excellent adhesive strength and workability, and does not cause foaming during vulcanization of the rubber sheet.

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C08L 23:04 95:00) F term (reference) 4F072 AA01 AA05 AA06 AA09 AD02 AD04 AD08 AD13 AD23 AD52 AG03 AK05 AL17 4J002 AG005 BB062 BB072 BB151 BB181 BB241 CC054 CD053 CD193 GL00

Claims (4)

[Claims] 1. A rubber sheet obtained by molding a rubber composition comprising rubber, a vulcanizing agent, an auxiliary agent, a reinforcing agent and other additives into a sheet and vulcanizing the rubber composition, wherein a polyethylene-based rubber composition is added to the rubber composition. A rubber sheet characterized by adding and kneading a resin, a liquid epoxy resin, an alkylphenol resin and a rubber-modified asphalt. 2. The rubber sheet according to claim 1, wherein the rubber contains any one of ethylene propylene rubber, isobutylene isoprene rubber and halogenated isobutylene isoprene rubber as a main component, and the polyethylene resin has reactivity with an epoxy group. A rubber sheet which is a polyethylene or a copolymer thereof modified with a functional group (excluding maleic anhydride). 3. The rubber sheet according to claim 1, wherein the polyethylene resin is an ethylene-vinyl acetate binary copolymer. 4. The rubber sheet according to claim 1, wherein the compounding amounts of the polyethylene resin, the liquid epoxy resin, the alkylphenol resin and the rubber-modified asphalt are each 100 parts by weight of the rubber composition. 15 to 30 parts by weight, 2.0 to 6.0 parts by weight,
A rubber sheet containing 0.2 to 1.8 parts by weight and 1.0 to 5.0 parts by weight.