JP2849180B2 - Resin composition for primer - Google Patents

Description

The present invention relates to a resin composition for a primer used for lining metals such as iron, stainless steel, and aluminum, and concrete.

[Conventional technology]

Epoxy acrylate resins are widely used for lining metals, such as iron, stainless steel, and aluminum, and concrete, because of their excellent corrosion resistance.

When lining the above base material with an epoxy acrylate resin, the base material is subjected to a surface treatment in advance by sandblasting or the like, and a primer resin is applied.

After that, a glass fiber impregnated with an unsaturated polyester resin or epoxy acrylate resin is lined to provide a corrosion resistant layer, or an unsaturated polyester resin mixed with glass flakes or an epoxy acrylate resin is troweled and sprayed. A corrosion resistant layer is provided by coating.

When performing the above lining, if the corrosion-resistant layer is formed of epoxy acrylate resin or unsaturated polyester resin without applying the primer resin to the base material, the adhesiveness with the base material is poor, Peeling occurs between the substrate and the corrosion resistant layer.

In order to prevent the peeling, an epoxy resin-based, urethane resin-based, epoxy acrylate resin-based primer or the like is usually applied.

Epoxy resin primers have excellent adhesion to metals, but the epoxy acrylate resin or unsaturated polyester resin at the interface in contact with the epoxy resin becomes uncured due to the effect of the epoxy resin curing agent. It has the disadvantage of being easy.

Urethane resin primers have good compatibility with epoxy acrylate resin or unsaturated polyester resin,
In a hot and humid work site, the curing speed is high, which causes inconvenience in the operation.

Further, when immersed in hot water, peeling (blister) between the substrate and the corrosion-resistant layer is likely to occur.

When an unsaturated polyester resin or an epoxy acrylate resin is used for a lining as a corrosion-resistant layer for such a reason, an epoxy acrylate resin-based primer is usually used.

The epoxy acrylate resin-based primer is usually cured with a combination of methyl ethyl ketone peroxide and an organic metal salt.

However, in this curing system, an uncured resin layer is generated under the influence of oxygen in the air, so that the performance required as a primer cannot be sufficiently brought out. In such a case, there is a disadvantage that the adhesion to the base material is reduced, and water penetrates between the base material and the primer in a system where hot water or the like is present, and blisters are easily generated.

In addition, conventional epoxy acrylate resin-based primers have lower adhesiveness to metals than epoxy resin-based primers, and blisters are liable to occur when immersed in hot water. Black rust easily occurs due to penetration.

[Problems to be solved by the invention]

The present invention solves the above-mentioned problems, and is hardly affected by oxygen in the air at the time of curing, has low adhesion to metal and generates little blister when immersed in hot water, or hardly generates a resin composition for a primer. Is provided.

[Means for solving the problem]

Means for Solving the Problems As a result of intensive studies, the present inventors have completed the present invention by using a specific curing agent in a composition comprising a specific epoxy acrylate resin and acrylic acid.

That is, the present invention relates to an epoxy acrylate obtained by reacting a bisphenol A type and / or bisphenol F type epoxy resin having at least two epoxy groups in one molecule with methacrylic acid, styrene and / or (meth) 100 parts by weight of an epoxy acrylate resin (A) comprising acrylic acid ester and 0.01 parts of acrylic acid (B)
To 10 parts by weight of a resin composition (C), a hydroperoxide (D) represented by the following general formula (I) and / or (II) and an organic cobalt salt (E) are used as a curing agent. Primer resin composition characterized by being cured by curing (R _{1 in} (I) is an alkyl group having 1 to 10 carbon atoms, a cyclohexyl group, a substituted cyclohexyl group, a phenyl group or a substituted phenyl group) R ₂ —OOH (II) (R _{2 in the} formula (II) Is H or an alkyl group having 1 to 10 carbon atoms).

The epoxy acrylate used in the present invention is obtained by a known esterification reaction from an epoxy resin and methacrylic acid.

As the epoxy resin to be used, bisphenol A,
Or an epoxy resin having an epoxy equivalent of 170 to 2000 obtained by reacting bisphenol F with epichlorohydrin, or in order to further improve adhesion and rust-proof curing,
A carboxyl group-terminated butadiene / acrylonitrile copolymer-modified epoxy resin having an epoxy equivalent of 200 to 5000 obtained by a reaction using an epoxy resin to which a carboxyl group-terminated butadiene / acrylonitrile copolymer has been added; Epoxy resin can be used in combination.

As the catalyst used in the above esterification reaction,
Compounds having a tertiary nitrogen such as triethylamine and imidazole derivatives exemplified in JP-A No. 45-40069, phosphorus compounds such as trimethylphosphine, and amine salts such as tetramethylammonium chloride and triethylamine hydrochloride are used.

The epoxy acrylate synthesized by the above method is usually used as an epoxy acrylate resin (A) by dissolving in the following vinyl.

Examples of the vinyl used in the present invention include (meth) acrylates such as styrene, chlorostyrene, divinylbenzene or methyl (meth) acrylate, and polyfunctional (meth) acryls such as ethylene glycol di (meth) acrylate. Acid esters and the like are used. These can be used alone or in combination of two or more.

The mixing amount of the vinyl monomer, preferably styrene and / or (meth) acrylate, is practically 10 to 150 parts by weight with respect to 100 parts by weight of the epoxy acrylate.

An optimum cured product can be obtained in the above-mentioned mixing ratio.

In the present invention, acrylic acid (B) is blended at a ratio of 0.01 to 10 parts by weight based on 100 parts by weight of the epoxy acrylate resin (A).

If the blending ratio of acrylic acid (B) is below the above range, the adhesion to metal decreases, and if it exceeds the above range, the hot water resistance decreases, causing blistering.

The resin composition for a primer of the present invention can be used as a curing agent in the resin composition (C) of the present invention as a compound represented by the general formula (I) and / or (I)
The hydroperoxide (D) shown in I) and the organic cobalt salt (E) are mixed, and the curing temperature is -10 to 60C, preferably-
Can be cured at 10-40 ° C.

As the hydroperoxide (D) used in the present invention, those represented by the general formulas (I) and / or (II) are used. For example, hydrogen peroxide, t-butyl hydroperoxide, cumene hydroperoxide, Examples thereof include diisopropylbenzene hydroperoxide, P-menthane hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, and 1,1,3,3-tetramethylbutyl hydroperoxide.

These can be used alone or in combination of two or more.

The hydroperoxide (D) can be used by dissolving it in water, a plasticizer, dimethyl fumarate or the like in order to improve the solubility in the resin.

Hydroperoxide (D) is a resin composition (C) 100
It is used in a proportion of 0.01 to 10 parts by weight, preferably 0.5 to 5 parts by weight with respect to parts by weight.

When the adjustment of the curing speed and the physical properties of the cured product are taken into consideration, the above mixing ratio is preferable.

As the organic cobalt salt (B) to be used at this time, an organic cobalt salt such as cobalt naphthenate and cobalt octenoate is used.

The amount of the organic cobalt salt (E) added depends on the amount of the resin composition (C).
0.01 to 10 parts by weight, preferably 0.1 to 10 parts by weight, per 100 parts by weight
3 parts by weight.

In consideration of workability and physical properties of the cured product, the above mixing ratio is preferable.

In the present invention, corrosion resistance and adhesiveness can be improved by using a resin composition (C) with a filler, if necessary.

Examples of the filler used in the present invention include talc, whiskers, mica, and bengara.

These have an effect of securing an appropriate coating film thickness and improving the adhesiveness or an effect of preventing rust when applied to an iron plate, and therefore can be used alone or in combination of two or more.

When the filler is blended in the present invention, the proportion of the filler is 5 to 200 parts by weight, preferably 5 to 150 parts by weight, per 100 parts by weight of the resin composition (C).

In consideration of the working viscosity at the time of curing and the corrosion resistance, the above mixing ratio is preferable.

 Hereinafter, the present invention will be described with reference to examples.

〔Example〕

The evaluation methods employed in this example and comparative examples are as follows.

(1) Measurement of tensile step strength One side of an iron plate (material: SS41) with dimensions of 150 × 25 × thickness 3 (mm) is sandblasted with a # 70 grid, immediately degreased with acetone, and then dried with a dryer. Let dry.

After applying the resin for primer up to 25 mm from the end of the iron plate surface subjected to the above treatment, after curing at room temperature for 24 hours,
After curing at 80 ° C. for 2 hours, a test piece for a tensile shear test was prepared.

 The tensile speed was measured under the condition of 1 mm / min.

The adhesive strength was a value obtained by dividing the maximum breaking load by the adhesive area.

(2) Evaluation of hot water resistance by immersion in hot water on one side Iron plate with dimensions of 200 x 200 x thickness 5 (mm) (material: SS41)
Was sandblasted with a # 70 grid, immediately degreased with acetone, and then dried with a drier.

Apply the primer resin to the iron plate surface that has been subjected to the above treatment, leave the primer resin in a constant temperature room at 25 ° C for 24 hours,
Cured.

For evaluation of hot water resistance by immersion in single-sided hot water, the primer-coated surface was immersed in hot water at 96 to 98 ° C., and the interface of the primer coating was observed every immersion for a predetermined time.

Example 1 In a four-necked flask equipped with a stirrer, an air inlet tube, a thermometer, and a condenser, a bisphenol A type epoxy resin (manufactured by Nippon Ciba Geigy Co., Ltd., trade name: Araldite # 26)
0) 1000g, methacrylic acid 455g, hydroquinone 0.58
g, 2.91 g of tetramethylammonium chloride, and 623 g of styrene, and reacted at 120 ° C. for 2.5 hours while paying attention to heat generation. An epoxy acrylate resin having an acid value of 7 was obtained.

347 g of styrene and 72.8 g of acrylic acid were added to the epoxy acrylate resin to obtain a resin composition (C-1).

Next, as a curing agent, 1.0 part by weight of 80% cumene hydroperoxide (manufactured by Kayaku Akzo Co., Ltd., trade name: Kayakumen H) and 100% by weight of the resin composition (C-1), and 6% cobalt naphthenate 0.5 part by weight (trade name: Naphtex Cobalt, manufactured by Nippon Chemical Industry Co., Ltd.) was blended to obtain a resin composition for primers (a).

Using the resin composition for primer (a), the tensile shear strength and the hot water resistance by immersion in single-sided hot water were evaluated.

 The evaluation results are shown in Tables 1 and 2.

Example 2 In a four-necked flask equipped with a stirrer, an air inlet tube, a thermometer, and a condenser, a bisphenol A type epoxy resin modified with a carboxyl group-terminated butadiene / acrylonitrile copolymer (manufactured by Dainippon Ink and Chemicals, Inc. Product name:
Epiclon TSR601) 1000 g, methacrylic acid 187 g, hydroquinone 0.47 g, tetramethylammonium chloride 2.37 g, styrene 600 g were charged and reacted at 120 ° C. for 3.5 hours while paying attention to heat generation to obtain an epoxy acrylate resin having an acid value of 5.

Styrene 371 g, acrylic acid
21.6 g was added to obtain a resin composition (C-2).

Next, the same curing agent as that used in Example 1 was mixed in the same ratio with the resin composition (C-2) to obtain a resin composition for primer (b).

Using the above resin composition for primers (b), tensile shear strength and hot water resistance by immersion in single-sided hot water were evaluated.

 The evaluation results are shown in Tables 1 and 2.

Example 3 100 g of the resin composition (C-1) used in Example 1
Was further added with 15 g of bengara and 50 g of talc as a filler, and sufficiently stirred to obtain a resin composition (C-3).

Next, t-butyl hydroperoxide (manufactured by NOF Corporation, trade name:
1.0 part by weight of perbutyl H) and 0.5 part by weight of 6% cobalt naphthenate (manufactured by Nippon Chemical Industry Co., Ltd., trade name: Naphtex Cobalt) were blended to obtain a resin composition for primer (c).

Using the above resin composition for primer (C), the tensile shear strength and the hot water resistance by immersion in single-sided hot water were evaluated.

 The evaluation results are shown in Tables 1 and 2.

Comparative Example 1 A four-necked flask equipped with a stirrer, an air inlet tube, a thermometer, and a condenser was charged with bisphenol A type epoxy resin (manufactured by Nippon Ciba Geigy Co., Ltd., trade name: Araldite # 26)
0) 1000g, methacrylic acid 455g, hydroquinone 0.58g,
Tetramethylammonium chloride 2.91 g, styrene 6
23 g was charged and reacted at 120 ° C. for 2.5 hours while paying attention to heat generation, to obtain an epoxy acrylate resin having an acid value of 6.

347 g of styrene was added to the resin obtained by the above reaction to obtain a resin composition (C-4).

80% as a curing agent in 100 parts by weight of resin composition (C-4)
1.0 part by weight of cumene hydroperoxide (manufactured by Kayaku Akzo Co., Ltd., trade name: Kayakumen H) and 0.5 part by weight of 6% cobalt naphthenate (trade name: Naphtex Cobalt, manufactured by Nippon Chemical Industry Co., Ltd.) Thus, a primer resin composition (d) was obtained.

Using the resin composition for primer (d), the tensile shear strength and the hot water resistance by immersion in single-sided hot water were evaluated.

 The evaluation results are shown in Tables 1 and 2.

Comparative Example 2 Resin composition (C-4) 100 produced in Comparative example 1
In parts by weight, 55% methyl ethyl ketone peroxide (manufactured by NOF Corporation, trade name: Permec N) as a curing agent 1.
0 parts by weight and 0.5 parts by weight of 6% cobalt naphthenate (manufactured by Nippon Chemical Industry Co., Ltd., trade name: Naphtex Cobalt) were blended to obtain a resin composition for primer (e).

Using the above resin composition for primer (e), tensile shear strength and hot water resistance by immersion in single-sided hot water were evaluated.

 The evaluation results are shown in Tables 1 and 2.

Comparative Example 3 Epoxy acrylate resin generally used for corrosion resistance (manufactured by Nippon Yupika Co., Ltd., trade name: Neopol 82)
50L) was used as the resin composition (C-5).

1.0 part by weight of 55% methyl ethyl ketone peroxide (manufactured by NOF Corporation, trade name: Permec N) per 100 parts by weight of the resin composition (C-5) as a curing agent, and 6
0.5% by weight of a cobalt naphthenate (manufactured by Nippon Chemical Industry Co., Ltd., trade name: Naphtex Cobalt) was blended to obtain a resin composition for primer (F).

Using the resin composition (F) for a primer, tensile shear strength and hot water resistance by immersion in single-sided hot water were evaluated.

 The evaluation results are shown in Tables 1 and 2.

Comparative Example 4 A commercially available epoxy acrylate resin for a primer having excellent adhesion to metal (Yupika Japan Co., Ltd.)
(Trade name: Neopol 8350H) was used as the resin composition (C-6) in the present invention.

As a curing agent, with respect to 100 parts by weight of the resin composition (C-6), 1.0 part by weight of 55% methyl ethyl ketone peroxide (manufactured by NOF Corporation, trade name: Permec N) and 6% of cobalt naphthenate (Nippon Chemical 0.5 part by weight of a trade name: Naphtex Cobalt manufactured by Sangyo Co., Ltd. was blended to obtain a resin composition for primer (g).

Using the above resin composition for primer (g), tensile shear strength and hot water resistance by single-sided hot water immersion were evaluated.

 The evaluation results are shown in Tables 1 and 2.

[Effects of the present invention] From the results in Tables 1 and 2, the primer resin composition of the present invention has better adhesiveness to metal than ordinary epoxy acrylate resin, and is immersed in hot water for 1000 hours. No blistering was observed at all. Further, it can be seen that oxidation of the interface between the base steel sheet and the primer due to permeation of water is less likely to occur at the primer coating interface after immersion in hot water than at the conventional epoxy acrylate resin-based primer.

Continuation of the front page (72) Inventor Takashi Takayanagi 5-6-1 Higashi-Hachiman, Hiratsuka-shi, Kanagawa Prefecture Mitsubishi Plastics Corporation Plastic Center (56) References JP-A-58-204057 (JP, A) JP-A Sho 49-26336 (JP, A) JP-A-63-15864 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09D 4/00, 4/02, 4/06, 163/10 C08F 290/06

Claims (3)

(57) [Claims] 1. Bisphenol A type and / or bisphenol F having at least two epoxy groups in one molecule
Acrylate obtained by reacting epoxy resin with methacrylic acid, styrene and / or (meth)
A resin composition (C) composed of 100 parts by weight of an epoxy acrylate resin (A) composed of an acrylate ester and 0.01 to 10 parts by weight of an acrylic acid (B) was added as a curing agent to the following general formula (I) and / or A resin composition for a primer, comprising a hydroperoxide (D) represented by (II) and an organic cobalt salt (E). (R _{1 in} (I) is an alkyl group having 1 to 10 carbon atoms, a cyclohexyl group, a substituted cyclohexyl group, a phenyl group, or a substituted phenyl group.) R ₂ —OOH (II) (R _{2 in the} formula (II) Is H or an alkyl group having 1 to 10 carbon atoms.) 2. The epoxy resin used in the present invention is an epoxy resin modified with a carboxyl group-terminated butadiene / acrylonitrile copolymer, or an epoxy resin mixture containing the modified epoxy resin. )) A resin composition for a primer. 3. The resin composition for a primer according to claim 1, wherein at least one kind of talc, whisker, mica or bengara is blended as a filler with respect to 100 parts by weight of the resin composition (C).