JPH06322344A - Acrylic pressure-sensitive adhesive composition - Google Patents

Abstract

PURPOSE:To provide an acrylic pressure-sensitive adhesive composition comprising a specific acrylic copolymer and a tackifier in specified amounts, respectively, excellent in initial adhesive characteristics and resistance to saline solutions, and useful for the adhesion between an organism-repelling metal plate and a belt-like article for lining an existing pipe. CONSTITUTION:The adhesive composition comprises (A) 100 pts.wt. of a 2-18C alkyl (meth)acrylate polymer, and (B) 5-40 pts.wt. of a tackifier comprising 60-90wt.% of a rosin (derivative) and 10-40wt.% of a petroleum resin or a hydrogenated terpene resin. The adhesive composition is useful for the adhesion of a belt-like article used for lining an existing pipe to a metal plate capable of reacting with sea water to generate a marine organism-repelling ingredient on the inner circumferential surface of a spiral pipe. The belt-like article is spirally wound, and the adjacent side ends of the wound belt-like article are engaged with each other to give the spiral pipe for lining the inner peripheral surface of the existing pipe.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strip-shaped body which is a lining pipe for rehabilitating an existing pipe, and marine organisms adhere to the inner peripheral surface of the existing pipe into which seawater enters. The present invention relates to an acrylic pressure-sensitive adhesive composition used for bonding a metal plate capable of reliably preventing such a phenomenon.

[0002]

2. Description of the Related Art A marine organism carried by seawater may adhere to the inner peripheral surface of a pipe into which seawater can enter such as a cooling pipe of a nuclear power plant. When marine organisms adhere to the inner peripheral surface of the cooling pipe, the adhered marine organisms hinder the flow of fluid inside, increasing the flow resistance of the liquid inside the pipe and decreasing the cooling efficiency. There's a problem.

For this reason, it has been practiced to coat the inner peripheral surface of the cooling pipe with a drug, a paint, or the like that prevents marine organisms from adhering thereto. In addition, Japanese Patent Publication No. 3-59754 discloses that when the seawater flowing through the pipe is stagnant, dissolved oxygen in the seawater is removed to kill marine organisms, and the inner circumference of the pipe. A method for preventing marine organisms from adhering to the surface is disclosed.

Further, when the pipe inner peripheral surface is lined with a spiral tube manufactured by spirally winding a band-shaped body,
The inner surface of the spiral tube, which is the inner surface of the spiral tube, is pre-attached with an adhesive film to cover the inner surface of the spiral tube with the film, and marine organisms adhere to the film. Later, we are also developing a method of peeling the film from the inner peripheral surface of the spiral tube.

However, the method of applying a drug or the like to the inner peripheral surface of the pipe may adversely affect the surrounding environment, and the method disclosed in Japanese Patent Publication No. 3-59754 removes dissolved oxygen in seawater. It is not easy to do.

Further, in the method of coating the inner peripheral surface of the spiral tube with a film or the like and peeling off the film after marine organisms have adhered, the film is attached to the inner peripheral surface of the spiral tube with an adhesive. Therefore, the film may peel off after long-term use.

As a solution to such a problem, a marine organism is prepared by lining a metal plate capable of reacting with seawater to generate a marine organism repellent component on the inner peripheral surface of a spiral tube. Can be largely prevented from adhering to the inner peripheral surface of the spiral tube.

[0008]

[Problems to be Solved by the Invention] However, in the past,
For bonding the metal plate and the strip, an olefinic hot melt adhesive having an appropriate elasticity has been used, but when the strip with metal plate for the existing pipe lining is used as a spiral pipe on the inner peripheral surface of the existing pipe, A large decrease in the adhesive strength after immersion in salt water was observed.

The present invention solves the above-mentioned conventional problems, and there is almost no decrease in the adhesive strength after immersion in salt water,
Adheres to the existing pipe lining strip that is a spiral pipe lining the inner peripheral surface of the existing pipe and the surface part that becomes the inner peripheral surface when it is a spiral pipe, reacts with seawater and generates marine organism repellent components The present invention has been made for the purpose of providing an acrylic pressure-sensitive adhesive composition capable of enhancing durable adhesion after immersion in salt water against a metal plate that can be treated.

[0010]

DISCLOSURE OF THE INVENTION According to the present invention, a spiral pipe which is lined on the inner peripheral surface of the existing pipe is provided by putting side edges adjacent to each other in a spiral shape into engagement with each other. Acrylic pressure-sensitive adhesive that bonds between the strip for pipe linings and the metal plate that can generate marine organism repellent components in reaction with seawater on the surface that becomes the inner peripheral surface when made into a spiral pipe An agent composition, which is 100 parts by weight of an acrylic copolymer (A) containing a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 18 carbon atoms as a main component, and a tackifying resin (B) 5 to 40 parts by weight (in terms of solid content), and the tackifying resin (B) further comprises 60 to 90% by weight of rosin or its derivative (a) and at least 1 selected from hydrogenated petroleum resin and hydrogenated terpene resin. 10 to 40% by weight of at least one resin (b) Ranaru is an acrylic pressure-sensitive adhesive composition.

In the present invention, the acrylic copolymer (A) containing a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 18 carbon atoms as a main component is an alkyl group having 2 to 18 carbon atoms. (Meth) acrylic acid alkyl ester having
It can be obtained by polymerizing or copolymerizing with a monomer which can be copolymerized with the monomer.

As the polymerization method, known methods such as bulk polymerization, solution polymerization, dispersion polymerization and emulsion polymerization can be adopted. The method of initiating the polymerization is also the one using a thermal polymerization initiator such as benzoyl peroxide, lauroyl peroxide, azobisisobutyronitrile, the one using a photopolymerization initiator such as benzoin, benzoin methyl ether, benzophenone and ultraviolet irradiation, or an electron beam. A method such as irradiation can be arbitrarily selected. The weight average molecular weight of the resulting acrylic copolymer (A) is preferably 200,000 or more.

Examples of the (meth) acrylic acid alkyl ester include ethyl (meth) acrylate, n-propyl (meth) acrylate and iso-propyl (meth).
Acrylate, n-butyl (meth) acrylate, se
c-Butyl (meth) acrylate, t-butyl (meth)
Acrylate, n-octyl (meth) acrylate, n
One or more of octyl (meth) acrylate, iso-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, dodecyl (meth) acrylate and the like are used. When the carbon number of the alkyl group is out of the range of 2 to 18, the characteristics as the pressure-sensitive adhesive are impaired, which is not preferable.

Examples of the monomer copolymerizable with the (meth) acrylic acid alkyl ester include (meth) acrylic acid, itaconic acid, 2- (meth) acrylic acid propane sulfonic acid, and (meth) acryloxyethyl phosphate. Examples thereof include polar acids such as unsaturated acids and hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate. These polar monomers are effective as a component that enhances the cohesive force of the pressure-sensitive adhesive.

In addition to the above polar monomers, methyl (meth)
It is also possible to use a monomer such as acrylate, styrene, vinyl acetate, (meth) acrylonitrile, (meth) acrylamide that gives a polymer having a high glass transition point.

In the present invention, the tackifying resin (B) is contained in an amount of 5 to 40 parts by weight in terms of solid content based on 100 parts by weight of the acrylic copolymer (A). When the addition amount of the tackifying resin (B) is less than 5 parts by weight, the effect of improving the peel strength becomes insufficient, and when it exceeds 40 parts by weight, the cohesive force and the tack force decrease.

In the present invention, the tackifying resin (B) is
It comprises rosin or its derivative (a) and at least one resin (b) selected from hydrogenated petroleum resins and hydrogenated terpene resins.

In the present invention, by using the tackifying resin (B) composed of the component (a) and the component (b), the adhesive property to an adherend having a low polarity surface at room temperature is excellent and Even at high temperatures, there will be little deterioration in physical properties. Conventionally, it has been said that a tackifying resin having excellent compatibility with an acrylic copolymer is preferable, but in the case of this type of pressure-sensitive adhesive composition, it is usually cross-linked in the film forming process and the like. However, at this time, a crosslinked portion and an uncrosslinked portion are usually formed because the acrylic copolymer has a molecular weight distribution and a high molecular weight polymer is more easily crosslinked.

Here, in the case of using the conventional tackifying resin having excellent compatibility, the tackifying resin is uniformly mixed with the acrylic copolymer, and the tackifying resin is uniformly present in the crosslinked portion and the non-crosslinked portion. Therefore, under high temperature, there is a strong tendency that all parts including the cross-linked part are uniformly plasticized,
This plasticization softens the entire body, which in turn reduces the cohesive strength. As a result, it is considered that the adhesive property at high temperature is deteriorated.

On the other hand, in the present invention, in the case where the tackifying resin (B) comprising the component (a) and the component (b) is used, the acrylic resin is used because of the low polarity of the resin itself. Hydrogenated petroleum resins, which have been considered to have poor compatibility with polymers, are made compatible by specifying the acrylic copolymer composition or by using rosin or a derivative thereof together. Due to lack of uniform mixing with A), it is expected that the tackifying resin will not enter the cross-linking portion, and as a result, plasticization in the cross-linking portion will not occur easily at high temperature, and the deterioration of the adhesive property will be small. It is considered to be.

Among the components (a), the latter derivatives include partially disproportionated or disproportionated rosin, hydrogenated rosin, maleic acid-modified rosin, polymerized rosin, formaldehyde-modified rosin, and metal salts thereof. Other diethylene glycol,
Esters such as glycerin and pentaerythritol are included. The resin softening point of rosin or its derivative (a) is preferably 75 ° C. or higher.

As the hydrogenated petroleum resin as the component (b), a C9 petroleum resin obtained by cationically polymerizing a C9 fraction obtained by cracking naphtha is hydrogenated, or is mainly composed of cyclopentadiene. It is a hydrogenated petroleum resin obtained by thermal polymerization of a C5 fraction or dicyclopentadiene derived from the C5 fraction, and means an alicyclic petroleum resin.

Here, α-methylstyrene, vinyltoluene, vinylxylene, propenylbenzene, indene, methylindene, etc. are contained as a polymerizable component in the C9 fraction, and usually the C9 fraction is a mixture of the polymerizable components. Available. The hydrogenation conditions for these petroleum resins are usually nickel, palladium, cobalt, ruthenium, platinum,
A metal such as rhodium or an oxide thereof is used as a hydrogenation catalyst, and the temperature is usually 200 to 300 ° C. and the pressure is 10 to 300 k.
The condition of g / cm ² is adopted.

As the hydrogenated terpene resin as the component (b), terpene fractions such as α-pinene, β-pinene and dipentene are subjected to cationic polymerization using a Friedel-Crafts catalyst such as aluminum chloride and boron trifluoride. It means a hydrogenated product of the terpene resin obtained by the above, or a hydrogenated product of a copolymer comprising a terpene fraction and styrenes.
As the hydrogenation conditions, the conditions of the petroleum resin can be adopted as they are. These may be used alone or in combination of two or more.

The mixing ratio of the component (a) and the component (b) in the tackifying resin (B) is 60 to 90% by weight of the component (a) and 10 to 40% by weight of the component (b). When the amount of the component (a) exceeds 90% by weight and the amount of the component (b) is less than 10% by weight, the adhesive property to an adherend having a low polarity surface,
Particularly, when the peeling resistance is hardly improved, the component (b) exceeds 40% by weight, and the component (a) is less than 60% by weight, the compatibility with the acrylic copolymer (A) decreases. Therefore, tack at room temperature and adhesive properties are extremely deteriorated.

The acrylic pressure-sensitive adhesive composition of the present invention may further contain a crosslinking agent in order to improve cohesive strength. As this cross-linking agent, conventionally known ones,
For example, an isocyanate type crosslinking agent, a melamine type crosslinking agent, an epoxy type crosslinking agent, a peroxide type crosslinking agent, etc. are mentioned.

If desired, the acrylic pressure-sensitive adhesive composition of the present invention may contain various conventionally known additives such as plasticizers, softeners, fillers, pigments and dyes. You may do it.

Hereinafter, the acrylic pressure-sensitive adhesive composition of the present invention is spirally wound to spirally line the inner peripheral surface of an existing pipe by engaging adjacent side edges with each other. Bond between the existing strip for pipe lining, which is a pipe, and the metal plate that can react with seawater to generate marine organism repellent components on the surface that becomes the inner peripheral surface when made into a spiral pipe It is used as an adhesive, but for an example of an existing pipe lining strip for pipe lining that is the object of its adhesion,
A description will be given with reference to the drawings.

As shown in FIG. 1, the existing strip-shaped strip 1 with a metal plate for pipe lining has a strip-shaped substrate 11, and one surface of the substrate 11 is protected from marine organisms. In order to prevent this, an adhesive layer 1 made of the acrylic pressure-sensitive adhesive composition of the present invention is formed on the entire surface of a strip-shaped metal plate 12.
Bonded by 3.

On the other surface of the substrate 11, one side surface 1
A fitting protrusion 14 is provided upright at an appropriate distance from 1a. The fitting protrusion 14 is continuous in the longitudinal direction of the substrate 11. The fitting protrusion 14 has a pillar portion 14a slightly longer than the thickness of the substrate 11, and an insertion portion 14b having a semicircular cross section arranged at the tip of the pillar portion 14a.

On the other side 11b side of the substrate 11,
When the board 11 is spirally wound, the board 11 portion between the side surface 11a on the side where the fitting projection 14 is arranged and the base end portion of the fitting projection 14 can be fitted. A step-down portion 15 is formed on the protruding side of the fitting projection 14 by the thickness of the board 11. In the middle of the step drop portion 15, the fitting protrusion 1
The fitting recess 16 formed in a semi-circular cross section having a semi-circular cross section into which the fitting portion 14b of No. 4 can fit is formed on the substrate 11.
Are provided along the longitudinal direction of.

As shown in FIG. 2, this strip 1 is supplied to a pipe making machine at a step-down portion 15 on one side of a substrate 11 which is already spirally wound in an existing pipe. The side portions of the first substrate 11 are fitted and overlapped with each other, and the fitting projection 14 is fitted into the fitting recess 16 of the step-down portion 15. Then, the insertion portion 14b of the fitting protrusion 14 is fitted into the fitting recess 1
6, the other side of the substrate 11 and the stepped-down portion 15 which are inserted into the space inside and are overlapped with a hot melt adhesive.
It is manufactured and used as a spiral tube so that and are bonded.

The belt-shaped plate substrate is integrally formed of a resin such as polyethylene, polypropylene, polyvinyl chloride, polycarbonate, polyester or the like.

The metal plate is a metal capable of reacting with seawater to generate a marine organism repellent component, and specific examples thereof include, but are not limited to, copper plates and alloys thereof. Regarding the thickness of the metal plate, the thickness of the belt-shaped substrate is 2 to 3
In the case of mm, the thickness is set to about 1/6 to 2/3 of the thickness of the strip substrate.

As a method of adhering the metal plate of the strip-shaped body with a metal plate for an existing pipe lining and the strip-shaped body with an acrylic pressure-sensitive adhesive, a solution of an acrylic pressure-sensitive adhesive dissolved in a solvent is applied to an adherend. After applying to one or both and drying the solvent, both adherends can be adhered.

[0036]

The acrylic pressure-sensitive adhesive composition of the present invention comprises 100 parts by weight of an acrylic copolymer (A) mainly composed of a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 18 carbon atoms. , Rosin or its derivative (a) 60 to 90 having excellent compatibility with the acrylic copolymer (A)
% And one or more resins (b) selected from hydrogenated petroleum resins and hydrogenated terpene resins, which have poor compatibility with the acrylic copolymer (A) due to the low polarity of the resin itself. 10
By using 5 to 40 parts by weight of the tackifying resin (B) made up of 40 to 40% by weight, the initial adhesion property to an adherend having a low polarity surface is excellent and the durable adhesion after immersion in salt water is improved. Because it is excellent, the existing pipe lining strip, which is a spiral pipe that lines the inner peripheral surface of the existing pipe,
It can be suitably used as an adhesive agent for adhering a surface portion, which becomes an inner peripheral surface when formed into a spiral tube, and a metal plate capable of reacting with seawater to generate a marine organism repellent component.

[0037]

EXAMPLES The present invention will be clarified by giving Examples and Comparative Examples of the present invention. (1) Polymerization of Acrylic Copolymer and Preparation of Acrylic Pressure-Sensitive Adhesive Composition Examples 1 to 5 and Comparative Examples 1 to 3 are shown in Table 1 in a separable flask equipped with a cooling tube, a stirrer and a thermometer. The following monomer composition was added, and the total amount of all monomers was dissolved in ethyl acetate so that the total weight ratio of the monomers was ethyl acetate = total monomer / ethyl acetate = 55/45.
Benzoyl peroxide was added to the obtained solution as a polymerization initiator.
062 parts by weight was added. The mixture was refluxed under nitrogen for 8 hours.
Polymerization was performed by stirring at 0 ° C. for 8 hours to obtain an acrylic copolymer solution.

Solid content 10 of the acrylic copolymer solution
A predetermined amount of the tackifying resin shown in Table 1 was added to 0 part by weight,
Further, as a cross-linking agent, N, N'-hexamethylene-1,6-
Bis (1-aziridinecarboxamide) (HDU) was mixed in an amount of 0.1 parts by weight to prepare Examples 1-5 and Comparative Examples 1-3.
The acrylic pressure-sensitive adhesive composition of was prepared. As the tackifying resin, tackifying resin: hydrogenated rosin pentaerythritol ester (softening temperature 105 ° C), tackifying resin: hydrogenated petroleum resin (softening point 145 ° C), tackifying resin: hydrogenated petroleum resin (softening 120 ° C.), tackifying resin: polymerized rosin pentaerythritol ester (softening point 160 ° C.), tackifying resin disproportionated rosin pentaerythritol ester (softening point 115 ° C.) were used.

[0039]

[Table 1]

Comparative Example 4 100 parts by weight of a modified silicone resin (trade name "Kaneka Cyril 5B25", molecular weight 8000, manufactured by Kanegafuchi Chemical Co., Ltd.), bisphenol A type epoxy resin (trade name "Epicoat 828", manufactured by Yuka Shell Epoxy Co., Ltd., Molecular weight 380) 50
Parts by weight, 2,4,6-tris (dimethylaminomethyl)
A modified silicone-epoxy elastic adhesive was prepared by using 5 parts by weight of phenol (tertiary amine curing agent) and 2 parts by weight of dibutyltin dilaurate.

Comparative Example 5 As a monomer composition, a bisphenol A type epoxy resin (produced by Yuka Shell Epoxy Co., Ltd. under the trade name "Epicoat 82"
8 ", molecular weight 380) 100 parts by weight, and triethylenetetramine 19.3 parts by weight were used to prepare an epoxy adhesive.

Comparative Example 6 Ethylene-ethyl acrylate resin (manufactured by Mitsui DuPont Polychemical Co., Ltd., trade name "EVAFLEX-EEA A-"
701 ", ethyl acrylate content: 9% by weight, MF
An adhesive having R: 5 dg / min and Vicat softening point: 73 ° C.) was prepared.

(2) Adhesive Sample Preparation Method and Adhesiveness Evaluation After applying the acrylic pressure-sensitive adhesive composition obtained above and the other adhesives to both adherends below, 100 ° C. × 10
The solvent is dried by heating for 2 minutes and both adherends at room temperature 1 kg / c
Adhesion was performed by applying a pressure of m ² .

The adhesive curing conditions are as follows: Comparative Example 4 at room temperature for 2 days, 50 ° C. for 3 days, Comparative Example 5 at room temperature for 3 days, and Comparative Example 6 at 200 ° C. The condition of 3 minutes was adopted.

With respect to each adhesive of Examples and Comparative Examples, the following small test piece adhesiveness evaluation and adhesiveness evaluation of a copper plate-attached synthetic resin strip were performed. Small test piece Adhesion evaluation Tensile shear test As an adherend, a 20 mm x 125 mm x 3 mm thick polyethylene plate and 20 mm x 125 mm x 0.5 mm thickness
With a copper plate having an adhesion area of 20 mm × 20 mm, and the initial adhesion strength (test method: conforming to JIS K6850, tensile speed: 50 mm / min, measurement temperature: 23
C) was measured. Next, as a durability evaluation, the test specimen was immersed in a 10% NaCl aqueous solution at a temperature of 60 ° C. for 5 days,
After taking out, it was dried and the adhesive strength was measured in the same manner as the above measurement.

90 ° Peeling Test As an adherend, a 20 mm × 125 mm × 3 mm thick polyethylene plate and a 20 mm × 125 mm × 0.5 mm thick
With a copper plate having an adhesion area of 20 mm × 100 mm, and the initial adhesion strength (test method: conforming to JIS K6854, tensile speed: 50 mm / min, measurement temperature: 23)
C) was measured. Next, as a durability evaluation, the test specimen was immersed in a 10% NaCl aqueous solution at a temperature of 60 ° C. for 5 days,
After taking out, it was dried and the adhesive strength was measured in the same manner as the above measurement. The results are shown in Table 2.

[0047]

[Table 2]

Adhesion evaluation of synthetic resin strip with copper plate 500 mm × 1000 mm × thickness polyethylene plate of 500 mm × 1000 mm × thickness as an adherend
A 5 mm copper plate is bonded with a bonding area of 500 mm × 1000 mm, the adherend is made into a cylindrical shape having a diameter of about 30 cm, and the test body is immersed in a 10% NaCl aqueous solution at a temperature of 60 ° C. for 5 days, taken out and dried, 90 ° peel strength (Test method: JIS K6854, test piece shape:
20 mm x 125 mm, pulling speed: 50 mm / mi
n, measurement temperature: 23 ° C.) was measured. The results are shown in Table 3.

[0049]

[Table 3]

As is clear from Tables 2 and 3, in all cases of Examples 1 to 5 of the present invention, small test piece adhesiveness evaluation (tensile shear test and 90 ° peeling test), copper plate attached synthetic resin In the band-shaped body adhesiveness evaluation (90 ° peeling test), the adhesiveness is excellent at the initial stage and after immersion in salt water, whereas in Comparative Examples 1 to 6, at least one of them is inferior.

[0051]

EFFECTS OF THE INVENTION The acrylic pressure-sensitive adhesive composition of the present invention, having the above-mentioned constitution, is excellent in the initial adhesive property to an adherend having a low polar surface, and after immersion in salt water. It has excellent durability and adhesiveness, and can be suitably used as an adhesive agent for adhering the existing pipe lining strip and a metal plate capable of reacting with seawater to generate a marine organism repellent component.

[0052]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a belt-shaped strip with a metal plate for an existing pipe lining, which is produced by using the acrylic pressure-sensitive adhesive composition of the present invention.

FIG. 2 is a cross-sectional view showing a main part of a spiral tube formed by using the strip-shaped body of FIG.

[Simple explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Band-like body 11 Substrate 12 Metal plate 13 Adhesive layer 14 Fitting protrusions 15 Step drop portion 16 Fitting concave lines

Claims (1)

[Claims] 1. An existing pipe lining strip, which is a spiral pipe that is lined on an inner peripheral surface of an existing pipe by making side edges that are spirally wound and adjacent to each other engage with each other, and a spiral. An acrylic pressure-sensitive adhesive composition for adhering between a metal plate capable of generating a marine organism repellent component by reacting with seawater, on a surface portion which becomes an inner peripheral surface when formed into a pipe,
100 parts by weight of an acrylic copolymer (A) containing a (meth) acrylic acid alkyl ester having an alkyl group having 2 to 18 carbon atoms as a main component, and a tackifying resin (B) of 5 to 40 parts by weight. The tackifying resin (B) is 60 to 90% by weight of rosin or its derivative (a), and 10 to 40% by weight of at least one resin (b) selected from hydrogenated petroleum resin and hydrogenated terpene resin. An acrylic pressure-sensitive adhesive composition comprising: