JPS63178041A - Water, acid or alkali aqueous solution housing - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water or acid-alkali aqueous solution container made of iron or an iron-based alloy, a mobile liquid storage container such as a drum, or an acid-alkali aqueous solution in a factory. This invention relates to water and acid-alkali aqueous solution storage bodies useful as installation-type liquid storage containers such as storage tanks and water tanks on building roofs, and transport pipes. In the present invention, iron or iron-based alloys refers to iron such as pure iron, pig iron, and cast iron, and iron alloys whose main component is iron such as various steels. Abbreviate.

Since flat strained metals generally have poor chemical resistance and corrosion resistance, there has been a growing demand for coating the outer and inner walls of metal products with a polyolefin layer having excellent chemical resistance and corrosion resistance. For this coating, it is necessary to firmly bond the metal wall and the polyolefin, but as is well known, polyolefin is a material that is extremely difficult to bond, so there is a problem that it cannot be bonded with ordinary adhesives.

Conventionally, methods for bonding metals and polyolefins include (11) roughening the surface of the metal to be bonded and/or the surface of the polyolefin to increase the bonding area and increase the bonding strength through an anchor effect; and (2) flame treatment. Methods have been proposed, such as forming a layer of easily adhesive polar substances such as polyolefin oxides on the surface of the polyolefin to be bonded by chemical treatment, or (3) using improved adhesives and improving the polyolefin itself. There is.

Problems to be solved With methods (1) and (2) above, a certain degree of adhesive strength may be obtained if the surface treatment is performed appropriately and sufficiently, but it takes a long time to perform sufficient surface treatment. There are problems with workability, such as the time it takes. Recently, various improved adhesives have been developed, but many of them are expensive or the mechanical strength of the adhesive itself is low, resulting in failure of the adhesive layer and causing the bonding between metal and polyolefin. There is a problem with peeling. Furthermore, improvements in the polyolefin itself have the problem of making it difficult to obtain a high level of adhesive strength.

In view of the above-mentioned conventional circumstances, there is a strong demand for the development of a method for easily and firmly adhering metals and polyolefins without surface treatment or with only a light surface treatment. In particular, iron-based liquids are generally inexpensive, and are easily corroded by water and acid-alkali aqueous solutions, which are frequently used. Therefore, a polyolefin layer is firmly attached to the inner wall of the iron-based liquid container to ensure water resistance and There is an increasing demand for acid-alkali resistance.

- In the present invention, the inner wall of the iron-type container main body whose surface has been polished in advance is coated with a polyolefin layer that has been surface-polished in advance and then ignited to form an epoxy, urethane, or silicone-based material. It is an object of the present invention to provide a water, acid-alkali aqueous solution container, characterized in that the container is lined with an adhesive selected from the group consisting of cyanoacrylates and cyanoacrylates.

The inner wall surface of the iron group type container body to be attached inside is polished, while the surface of the polyolefin layer to be attached inside is polished and then subjected to ignition treatment. Using at least one type of adhesive selected from the group consisting of epoxy, urethane, silicone, and cyanoacrylate adhesives, strong adhesion can be achieved at room temperature in a normal adhesive manner.

In the present invention, for example, mobile liquid storage containers such as drums, stationary liquid storage containers such as acid-alkali aqueous solution storage tanks in factories and water supply tanks on the rooftops of buildings, and transport pipes are made of iron that is to be lined with polyolefin. This can be cited as an example of a family-type container body.

The inner wall surface of the iron-based housing body to be lined is polished prior to the lined side. This polishing is performed for the purpose of removing rust from the surface layer and adding irregularities to increase the effective bonding area. Any polishing method may be used as long as this purpose is achieved, but it is preferable to uniformly polish the surface using an abrasive or polishing means with a grain size of No. 30 to No. 400 specified in JIS-R6001, for example. Examples include abrasive cloth (JIS-R6521), abrasive paper (JI
S-1?6252), 7L/t to Ken R (JIS-R62
5'2), a polishing disk (JAS-R6255), etc. can be used. If the abrasive grain size is finer than No. 400, the workability is poor and it may be difficult to polish uniformly, so that a sufficient effect may not be expected. On the other hand, if it is coarser than No. 30, the iron group surface may be damaged. Also, caution is required as the workability may be inferior.

Polyolefins used as inner lining materials include homopolymers and copolymers of α-olefins such as ethylene, propylene, and butene-1, such as high-density polyethylene, medium-density polyethylene, low-density polyethylene, very low-density polyethylene, and straight Polyethylenes such as chain low density polyethylene, polypropylene, polybutene-11 poly-4
- Various copolymers of ethylene and various copolymerizing agents other than α-olefin, such as methylpentene-1, ethylene-propylene copolymer, ethylene-butene-1 copolymer, etc., such as ethylene-vinyl acetate copolymer, These include ethylene-methyl acrylate copolymer and ethylene-ethyl acrylate copolymer. In addition, the polyolefin referred to in the present invention may be crosslinked or non-crosslinked, and the crosslinked polyolefin has a gel fraction of 10% or more, more preferably a gel fraction of 10% or more. A crosslinked polyolefin of 50% or more is suitable. As such crosslinked polyolefins, a wide variety of conventionally known ones can be used.

More specifically, f8!1 peroxide is added to the above polyolefin and crosslinked by heat treatment, the above polyolefin is irradiated with an electron beam to make a crosslinked polyolefin, or a water crosslinkable polyolefin is crosslinked. I can give examples of things like this.

The surface of the polyolefin is first polished, but this can be done in the same way as polishing the inner wall of the iron group housing body, and in this case, an abrasive or polishing means with a grain size of #30 to #400 according to JIS-R6001 is used. It is preferable to uniformly polish the surface of the polyolefin by using a polishing agent.

Next, the polished polyolefin surface is subjected to ignition treatment. A wide range of known methods such as flame treatment and hot air treatment can be applied to this ignition treatment. Gas burners can be used for flame treatment, and hot jets can be used for hot air treatment.

When performing the ignition treatment, it is preferable to uniformly apply flame or hot air of at least 250° C. or higher to the surface of the polyolefin for at least 0.1 seconds to the extent that the surface of the polyolefin to be bonded is not burnt. Although it depends on the thickness and shape of the polyolefin used as the inner lining material, in order to prevent the polyolefin from deforming due to heat, it is practical from the viewpoint of workability to carry out the process at as high a temperature as possible and in a short time. Therefore, treatment with a heat source of 500° C. or higher for about 0.5 to 10 seconds is more preferable. If the ignition temperature is lower than 250° C. or if the ignition treatment time is less than 0.1 seconds, it is not preferable because it is difficult to expect the desired effect of the present invention.

The above-mentioned pretreated inner wall of the iron group housing main body and the polyolefin are adhered with the following adhesive.

As the adhesive, epoxy adhesive, urethane adhesive, silicone adhesive, or cyanoacrylate adhesive may be used alone, or two or more types may be used in combination.

As the epoxy adhesive, a wide variety of conventionally known adhesives can be used, such as those containing a bisphenol A type epoxy resin, an amine curing agent, a polyamide resin or a polysulfide resin curing agent, etc. The bisphenol A type epoxy resin preferably has an epoxy equivalent of 140 to 300 and is liquid at room temperature.

In addition, as amine-based curing agents, aliphatic amines (primary,
Examples include epoxy adhesives (secondary and tertiary), aromatic amines, polyamide amines, etc., and modified products thereof. Among these, those that are liquid at room temperature are preferable. Such epoxy adhesives include ordinary fillers and colorants. , a reactive diluent, etc. may also be added. The epoxy adhesive is usually used by mixing an epoxy resin and a curing agent immediately before bonding, and after bonding at room temperature, it may be heated at a relatively low temperature of 50 to 60° C. if necessary.

As the urethane adhesive, a wide variety of conventionally known adhesives can be used, such as those blended with polyisocyanate and polyol. The polyisocyanate is preferably one that is liquid at room temperature, and the polyol is preferably a polyol or polyurethane polyol that is liquid at room temperature. Conventional fillers, colorants, curing catalysts, etc. can also be added to such urethane adhesives. Like epoxy adhesives, urethane adhesives are also used by mixing polyisocyanate and polyol immediately before bonding.

As the silicone adhesive, a wide range of conventionally known ones can be used, such as room temperature curing silicone adhesives,
It can be roughly divided into two-component type and one-component type.

The two-component type is a mixture of a polysiloxane having an O'H terminal (terminally reactive polysiloxane) and a crosslinking agent such as a tetraalcodisilane or a tetraalkyl titanate.

- Waveforms are mainly composed of polysiloxane containing acetoxy groups (acetic acid generating type), polysiloxane containing alkoxy groups (alcohol generating type), etc., and curing catalysts, fillers, etc. are added as appropriate. You can leave it there.

As the cyanoacrylate adhesive, a wide variety of conventionally known adhesives can be used, such as those containing α-cyanoacrylate as a main component. Examples of α-cyanoacrylate include methyl α-cyanoacrylate and ethyl α-cyanoacrylate.

When bonding the inner wall of the container and the polyolefin to each other using the above adhesive, it is sufficient to apply the above adhesive to one or both of the inner wall of the container and the polyolefin at room temperature and bring the two into contact. Pressure or heating may be applied depending on the situation. The amount of adhesive to be applied varies depending on the type of adhesive used, the shape of the inner wall of the container to be adhered, etc., but it cannot be generalized, but in terms of -a, 0.0
It may be applied to a thickness of about 1 to 1 dragon. There is no particular restriction on the method of applying the adhesive, and a wide range of commonly used means can be employed.

Since the present invention, the present invention has excellent resistance to water and acid-alkali aqueous solutions such as tap water, hot water, hot spring water, sea water, sulfuric acid water, hydrochloric acid water, nitric acid water, acetic acid water, caustic soda water, and caustic potash water. Various types of iron-group containers shown in the table are industrially possible, such as mobile liquid storage containers such as drums, stationary liquid storage containers such as acid-alkali aqueous solution storage tanks in factories and water tanks on the roofs of buildings, and transportation pipes. becomes.

Ōshi The present invention will be explained in more detail below with reference to Examples and Comparative Examples.

Examples 1 to 7, Comparative Examples 1 to 2 A polyolefin sheet having a thickness of 1.5 mm and made of the material shown in Table 1 was placed on the inner wall of a container made of the material shown in Table 1 and having a length of 500 m, a medium length of 400 m, and a depth of 300 cm. I pasted it inside.

After degreasing the inner wall surface of the container prior to lining,
The surface of the polyolefin sheet was polished with No. 0 abrasive paper, while the surface of the polyolefin sheet was abraded with No. 150 abrasive paper, and then flame treated with a gas burner for about 5 seconds, so that both the inner wall of the pipe and the polyolefin sheet were coated with No. Both were adhered by applying the adhesive shown in the table. In the comparative example, only the inner wall of the pipe was surface-treated, and the polyolefin sheet was not surface-treated.

After the lining work, the adhesive part was left under pressure at room temperature for 72 hours, and then the containers of Examples 1 to 5 and Comparative Example 1 were coated with 60
The containers of Examples 6 to 7 and Comparative Example 2 were filled with 68.5% sulfuric acid at 60°C and 28% caustic soda at 60°C, and the chemical resistance was examined for 21 days. In Examples 1 to 7, no particular abnormality was observed on the inner wall of the container, and the adhesive strength (180
Peel strength: JIS K 6854) However, blistering occurred in the inner sheet part after 24 hours in Comparative Example 1 and 48 hours in Comparative Example 2, and the adhesive strength at that point was the value shown in Table 1. Met.

Table 1 The materials used and the terms shown in Table 1 are as follows.

Polyolefin-1: 0.15 parts of dicumyl peroxide per 100 parts (parts by weight, same hereinafter) of high-density polyethylene with a density of 0.945 and a melt index of 0.2,
2.0 parts of vinyltrimethoxysilane, and dibutyl-
Crosslinked polyethylene with a degree of crosslinking of 70% obtained by mixing 0.05 part of tin-dilaurate, grafting modification for about 2 minutes in an extruder controlled at 200°C, and then crosslinking by molding.

Polyolefin-2: polyethylene with a density of 0.945 and a melt index of 0.2.

Polyolefin-3: 170 per composition obtained by mixing 2.0 parts of dicumyl peroxide and 0.3 parts of antioxidant with 100 parts of low-density polyethylene having a density of 0.920 and a melt index of 1.0. Crosslinked polyethylene with a degree of crosslinking of 85% obtained by press molding and crosslinking at °C for 30 minutes.

Epoxy system: Product name Arteco 350 manufactured by Alpha Giken Co., Ltd.
0゜Urethane system: Manufactured by Sanyo Chemical Co., Ltd., product name Unibon so o
o.

Cyanoacrylate: Trade name Aron Alpha 232° manufactured by Toagosei Co., Ltd. Silicone system: Trade name KE67RTV manufactured by Shin-Etsu Chemical Co., Ltd.

EVA; melt index 3, vinyl acetate content 2
5% ethylene-vinyl acetate copolymer.

Claims (1)

[Claims] 1. The inner wall of the container body made of iron or iron-based alloy whose surface has been polished in advance is coated with a polyolefin layer that has been surface-polished and then ignited to contain epoxy-based, urethane-based, silicon-based, and cyanoacrylate. 1. A water/acid-alkali aqueous solution container, characterized in that the inner surface is pasted using at least one type of adhesive selected from the group consisting of: 2. Claim 1, in which the container body made of iron or iron-based alloy is a pipe, a mobile liquid storage container, a stationary liquid storage container, etc.
The water, acid-alkali aqueous solution container described in 2. 3. The water and acid-alkali aqueous solution container according to any one of claims 1 to 2, wherein the polyolefin is a crosslinked polyolefin.