JPS62181363A - Primer composition - Google Patents

Abstract

PURPOSE:The titled composition useful as an undercoating agent, having firm adhesivity to polyolefin type vulcanized rubber, vinyl chloride resin, etc., obtained by blending chloroprene rubber with an acrylic monomer in a specific ratio, a Lewis acid and an organic solvent and polymerizing. CONSTITUTION:The aimed composition, a mixture comprising (A) chloroprene rubber, (B) an acrylic monomer [preferably (meth)acrylic acid or their derivatives], (C) a Lewis acid [preferably inorganic acid and the amount of the Lewis acid is 0.1-20pts.wt. based on 100pts.wt. total amount of the solid content of the component A and the component B] and (D) an organic solvent (e.g., n-hexane, benzene, THF, methyl ethyl ketone, etc.,) wherein 10-500pts.wt. component B is blended and polymerized with 100pts.wt. solid content of the component A.

Description

[Detailed Description of the Invention] Purpose of the Invention (Field of Industrial Application) The present invention is applicable to the surface of various synthetic rubbers including polyolefin vulcanized rubber, or various synthetic resins including polyolefin synthetic resins and vinyl chloride. This invention relates to a primer composition that is applied as an undercoat to strengthen the adhesion of paints and adhesives to surfaces.

(Prior art) There are many types of industrial rubber products, especially ethylene-propylene-diene ternary copolymer rubber (EPDM).
Polyolefin vulcanized rubbers such as ethylene-propylene copolymer rubber (EPM) have excellent weather resistance, aging resistance, and ozone resistance, and can also be used in a wide range of temperatures from -50°C to 150°C. Because it is a rubber with excellent features such as , it is now used in many fields. In addition, depending on the application, the above EPDM or EPM
Natural rubber (NR), styrene-butadiene copolymer rubber (SBR), butadiene rubber (BR), inbutylene-
Isoprene copolymer rubber (IrR), chloroprene rubber (
CR), acrylonitrile-butadiene copolymer rubber (N
Rubber blended with synthetic rubber such as BR) or A
BS resin, styrene resin (PS), polyethylene (PS)
), rubber blended with resins such as polypropylene (PP) are also used in many fields.

In addition, polyolefin-based synthetic resins such as the above-mentioned PP and PR have excellent performance in terms of weather resistance, aging resistance, ozone resistance, etc., as well as polyolefin-based vulcanized rubber, and are also inexpensive, so they are used in various types of vehicles. It is used in a wide range of applications such as parts and electrical products.

(Problem to be Solved by the Invention) However, polyolefin vulcanized rubbers such as EPDM and EPM, and polyolefin synthetic resins such as PP and PR, do not contain polar groups in the main chain of their molecules, so they are reactive. The problem is that even if paint or adhesive is applied to the surface of a molded product made from these rubbers or resins, the resulting coating film is likely to peel off.

However, although many countermeasures have been attempted to address the above-mentioned drawbacks, no satisfactory solution has yet been found.

In addition, with molded products made from resins containing large amounts of plasticizer, such as vinyl chloride, the plasticizer migrates to the surface after long-term use, so paints and adhesives applied to the surface do not adhere well. The disadvantage is that the power gradually decreases.

As a result of repeated research in view of the above problems, the present inventor has arrived at the present invention by discovering a primer composition that has strong adhesion to polyolefin vulcanized rubber, polyolefin synthetic resin, vinyl chloride, etc. This is what I did.

Constitution of the Invention (Means for Solving Problems) That is, the present invention comprises fat chloroprene rubber, (b) an acrylic monomer, (C) a Lewis acid, (d) an organic solvent,
A mixture consisting of 10 to 5 parts of acrylic monomer based on 100 parts by weight of the solid content of the polychloroprene.
The above-mentioned problems have been solved by devising a primer composition which is mixed and polymerized in a proportion of 0.00 parts by weight.

(Function) By blending the acrylic monomer and the above acid with chloroprene rubber, which has high polarity and high cohesive strength, the acid is added to the double bond in the acrylic monomer molecule, increasing the polarity of the primer composition. However, since the adhesion is strengthened and the surface of the rubber or synthetic resin to be coated is also oxidized, the adhesion of this primer composition becomes extremely strong.

(Example) Hereinafter, the constituent components of the primer composition of the present invention will be explained by giving specific examples.

First, the acrylic monomer is acrylic acid, methacrylic acid, or derivatives thereof, and polyacrylic acid m8
Specifically, methyl acrylate, ethyl acrylate, n-butyl acrylate, 1so-butyl acrylate, 2-ethylhexyl acrylate, isodecyl acrylate, 2-hydroxyethyl acrylate, 2
Examples include -hydroxypropyl acrylate, glycidyl acrylate, and dimethylamine ethyl acrylate.

In addition, methacrylic acid derivatives include methyl methacrylate, ethyl methacrylate, n-butyl methacrylate,
Examples include 1so-butyl methacrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, glycidyl methacrylate, and dimethylaminoethyl methacrylate.

The above acrylic acid, methacrylic acid, or these 3A conductors may be used alone, or several types may be mixed as appropriate.

In addition, the acids used in the present invention specifically include sulfuric acid, nitric acid,
Nitrous acid, hydrochloric acid, phosphoric acid, phosphorous acid, pyrophosphoric acid, metaphosphoric acid, tripolyphosphoric acid, tetrapolyphosphoric acid, orthoboric acid, metaboric acid, hydrobromic acid, hydrofluoric acid, hydroiodic acid, carbonic acid, hydrogen sulfide Inorganic acids such as AlCl
3.Aj213r, ,AJFz,GaF, ,InF,
,.

Tj? F3, Ga CA':l, PClz, PC
l3, S b Cj23, S b CI S , F
e Ce 2F B : O(CHa)z C/ ward CR-s : o (c H3)z and.

F　B　　OCCtHs　z) Lewis acids such as

Next, organic solvents are saturated hydrocarbons such as n-hexane and cyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; ethers such as dioxane and tetrahydrofuran; acetate esters such as ethyl acetate and propyl acetate; The solvent is a solvent appropriately selected from ketones such as 1 setone, cyclohexanone, and methyl ethyl ketone, or a mixed solvent consisting of two or more thereof.

The primer composition of the present invention can be obtained by polymerizing the above chloroprene rubber and an acrylic monomer in a solvent using a polymerization initiator such as benzoyl peroxide, and then adding an acid.
The blending ratio of acrylic monomer to 0 parts by weight is 10~
Preferably, it is 500 parts by weight. If the acrylic monomer exceeds 500 parts by weight, the hardness will gradually increase and the resulting primer composition will tend to become brittle when applied to the object to be coated. The adhesion of the coating film to the surface decreases.

In addition, when the acid is an inorganic acid, it is preferable to mix the above acid in a ratio of 0.1 to 20 parts by weight with respect to the solid content of chloroprene rubber and 100 parts by weight of 13i of the acrylic monomer, and the acid is 0.01 parts by weight. If it is less than 20 parts by weight, the adhesion will decrease, and if it exceeds 20 parts by weight, no improvement in adhesion can be expected.

By blending a polymer of chloroprene rubber, an acrylic monomer, and an inorganic acid, the acid is added to the double bond in the acrylic monomer molecule.

A primer composition with increased polarity and strong adhesion can be obtained. Furthermore, since the surface of the object to be coated is also oxidized by this inorganic acid, the adhesion of the primer composition becomes even stronger.

Furthermore, when the acid is a Lewis acid, the total IIO of the solid content of chloroprene rubber and the acrylic monomer.

It is preferable to mix the above acid in a proportion of 0.1 to 30 parts by weight. If the acid is less than 0.1 part by weight, the adhesion will decrease, while if it exceeds 30 parts by weight, the adhesion will decrease. No improvement can be expected.

When this Lewis acid is blended, the same effect can be obtained when the above-mentioned non-alpha acid is blended, and furthermore, there is a double bond in the molecule of the object to be coated, ω4! In the case of ↓, the polarity of the surface of the object to be coated can be increased because the Lewis acid is added to this double bond.

Next, the above primer composition is applied to various synthetic resins such as PP, PE and vinyl chloride, or polyolefin vulcanized rubber such as EPDM and EPM, and furthermore, the properties of polyolefin vulcanized rubber are The above NR, 'SBR,, I IR, CR,
, rubber components such as NBR, ABS resin, I's, PE,
Rubbers containing resin components such as PP and ethylene-vinyl acetate copolymer resin (EVA) are also included.

In addition, the above-mentioned polyolefin-based vulcanized rubber and the rubbers to which various rubber components and resin components as exemplified above are added include compounds that are usually used, namely: 1, ■ 2-mercaptopenzothiazole, zinc dimethyldithiocarbamate, tetramethylthiuram disulfide as a vulcanization accelerator, ■ Phenyl-α-naphthylamine, 2゜6-di as an anti-aging agent, antioxidant, and ozone deterioration inhibitor. L-butyl-p-cresol, (1) carbon black, magbutium carbonate, clay as a filler, (2) dioctyl sebacate, mineral oil, etc. as a plasticizer are added.

Additionally, no special equipment is required to apply the primer composition of the present invention to the surface of the base material made of rubber or resin as described above, and the primer composition can be simply applied using a normal coating method such as dipping, spraying, or brushing. That's fine.

Furthermore, since the primer composition is a one-component type, it has a very long pot life, and if the viscosity increases due to evaporation of the solvent, it can be reused by adding the solvent again to adjust the viscosity.

Examples of the primer composition of the present invention are listed below. (
Hereinafter, all parts are by weight. ) Following Example-1~
All acids in the primer composition listed in No. 7 are inorganic acids.

Example-1 99.9 parts of solid content of chloroprene rubber, 10.0 parts of methyl methacrylate, and 0.05 parts of benzoyl peroxide (BPO) as a polymerization initiator were mixed in a mixed solvent of toluene/n-hexane-1/1 4850 A polymer was obtained by dissolving the polymer in the same volume and reacting at 80°C for 18 hours. Next, 0.1099 part of 0°IN nitric acid was added to the obtained viscous liquid and mixed to obtain a primer composition.

Example-2 Solid content of chloroprene rubber: 95.0 parts, 95.5 parts of ethyl methacrylate, and BPOo as a polymerization initiator.
05 parts was dissolved in 4850 parts of a mixed solvent consisting of toluene/n-hexane=1/1, and a reaction was carried out at 80° C. for 8 hours to obtain a polymer. Then, the resulting viscous liquid was mixed with 0. I
5.0 parts of N sulfuric acid was added and mixed to obtain a primer composition.

Example-3 Solid content of chloroprene rubber: 80.0 parts, 1-160.0 parts of ethyl methacrylate, and BPOo as a polymerization initiator.
, 05 parts were dissolved in 4,850 parts of a mixed solvent consisting of toluene/n-hexane=1/l, and a reaction was carried out at 80° C. for 8 hours to obtain a polymer. Then, the obtained viscous liquid was added with 0.05
10.0 parts of N-hydrochloric acid was added and mixed to obtain a primer composition.

Example-4 Solid content of chloroprene rubber: 50.0 parts, methyl acrylate: 50.0 parts, and BPoo, 0 as a polymerization initiator.
5 parts were dissolved in 4850 parts of a mixed solvent consisting of toluene/n-hexane=1/l, and a reaction was carried out at 80°C for 8 hours to obtain a polymer. Next, 10.0 parts of 0.05N phosphoric acid was added to the obtained viscous liquid and mixed to obtain a primer composition.

Example-5 20.0 parts of solid content of chloroprene rubber, 100.0 parts of propyl methacrylate, and BPOo as a polymerization initiator
, 05 parts were dissolved in 4,850 parts of a mixed solvent consisting of toluene/n-hexane = 1/1, and a reaction was carried out at 80°C for 18 hours to obtain a polymer. Then, the resulting viscous liquid was mixed with 0.
10 parts of IN birophosphoric acid was added and mixed to obtain a primer composition.

Example-6 10.0 parts of solid content of chloroprene rubber, 1.0 parts of propyl acrylate, and BPoo, 05 as a polymerization initiator
1 part was dissolved in 4,850 parts of a mixed solvent consisting of toluene/n-hexane (7=1/1), and a reaction was carried out at 80° C. for 8 hours to obtain a polymer. Then, the resulting viscous liquid was mixed with 0. 1.0 part of IN hydrobromic acid was added and mixed to obtain a primer composition.

Example-7 80.0 parts of solid content of chloroprene rubber, 80.0 parts of methyl methacrylate, 80.0 parts of ethyl methacrylate, and 05 parts of BPOo as a polymerization initiator were mixed with toluene/n
-Mixture consisting of hexane = 171? A polymer was obtained by dissolving 8 drugs in 4850 pieces and reacting at 80°C for 8 hours. Next, 10.0 parts of 0, IN nitrous acid was added to the obtained viscous liquid and mixed to obtain a primer composition.

Next, examples of primer compositions containing Lewis acids are listed. (Examples-8 to 14) Example-8 99.9 parts of solid content of chloroprene rubber, 10.0 parts of methyl methacrylate, and 2.0 parts of BPO as a polymerization initiator.
5 parts were dissolved in 4850 parts of a mixed solvent consisting of toluene/n-hexane = 1/1, and a reaction was carried out at 80°C for 8 hours to obtain a polymer. The resulting viscous liquid was then applied with Arc! ,0
．． 1 part was added and mixed to obtain a primer composition.

Example-8 Solid content of chloroprene rubber: 99.9 parts, methyl methacrylate: 10.0 parts, and BPOo, 0 as a polymerization initiator.
5 parts were dissolved in 4850 parts of a mixed solvent consisting of toluene/n-hexane = 1/1, and a reaction was carried out at 80°C for 8 hours to obtain a polymer. The resulting viscous liquid was then treated with AAC! 30
．． 1 part was added and mixed to obtain a primer composition.

Example-9 95.0 parts of solid content of chloroprene rubber, 95.0 parts of ethyl methacrylate, and 0.5 parts of BPOo were dissolved in 4850 parts of the above mixed solvent and reacted under the same conditions as above to obtain a polymer. Ta. Then, 71,1Br was added to the resulting viscous liquid.
= 5.0 parts and mixed to obtain a primer composition.

Example-10 80.0 parts of solid content of chloroprene rubber, 160.0 parts of ethyl methacrylate, and 0.5 parts of BPOo were dissolved in 4850 parts of the above mixed solvent and reacted under the same conditions as above to obtain a polymer. Ta. Then, FeCl3 was added to the obtained viscous liquid.
20.0 parts were added and mixed to obtain a primer composition.

Example-11 50.0 parts of solid content of chloroprene rubber, 50.0 parts of methyl acrylate, and 05 parts of BPOo were added to the above mixed solvent 4.
The polymer was dissolved in 850 parts and reacted under the same conditions as above to obtain a polymer. The resulting viscous liquid was then injected with 5bcI! 54
30.0 parts were added and mixed to obtain a primer composition.

Example 12 20.0 parts of solid content of chloroprene rubber, 0 parts of propyl methacrylate, 0 parts of BPO, were dissolved in 4850 parts of the above mixed solvent, and reacted under the same conditions as above to form a polymer. I got it. Next, 1.0 part of F B : OCCtHs )t was added to the obtained viscous liquid and mixed to obtain a primer composition.

Example-13 10.0 parts of solid content of chloroprene rubber, 1.0 parts of propyl acrylate, and 05 parts of BPOo were added to the above mixed solvent 4.
The polymer was dissolved in 850 parts and reacted under the same conditions as above to obtain a polymer. Then, the obtained viscous liquid was treated with PC7!51.
0 parts were added and mixed to obtain a primer composition.

Example-14 80.0 parts of solid content of chloroprene rubber, 80.0 parts of ethyl methacrylate, 80.0 parts of methyl methacrylate and 0.5 parts of BPOo were dissolved in 4850 parts of the above mixed solvent, and the mixture was dissolved under the same conditions as above. A polymer was obtained by reaction.

Next, 1.0 part of P (1!, 1.0 part) was added to the obtained viscous liquid and mixed to obtain a primer composition.

Next, 20.0 parts of FeCJz was added to the obtained viscous liquid and mixed to obtain a primer composition.

Next, tests conducted to examine the adhesion of the primer compositions of Examples 1 to 14 and their results will be explained.

Test method: After extrusion molding an EPDM compound having the composition shown in Table 1, the temperature was 160°C.
, EPDM with 10X10X2 long thickness after 30 minutes vulcanization treatment
Two test pieces were prepared.

Next, as shown in the figure, the primer composition of Example 1 was applied to one end of each of the two test pieces 3, and then air-dried for 30 minutes at room temperature to form a primer layer 1. Next, the re-test piece 1 was bonded via a chloroprene rubber adhesive 2 consisting of each component shown in Table 2, left at room temperature for 24 hours, and then pulled in the direction of the arrow in the figure to determine its tensile shear. The strength was measured and the results shown in Table 3 were obtained.

Table 1 also shows the tensile shear strength measured after leaving this joined test piece l in an 80°C atmosphere for 5 hours.
Shown in 3.

Table 2 Table 3 also shows the results of similar tests using each of the brimer compositions of Examples 2 to 14.

Table 3 (Unit: kg/18mm2) Next, using a vinyl chloride resin base material obtained by extrusion molding a mixture consisting of each component shown in Table 4 at 170°C,
X I Q X A test piece with a thickness of 2 mm was prepared. Next, Example-1 was applied to each end of the two test pieces using the method described above.
After applying each of the brimer compositions,
A single layer of primer was formed by air drying for a minute, and a retest piece was bonded via the chloroprene rubber adhesive and left at room temperature for 24 hours. Moreover, the same operation was performed for the primer compositions of Examples 2 to 14.

Table-4 After that, the tensile shear table-5 (
Unit: kg/18mm2) From the above test results, all of the primer compositions of Examples 1 to 14 exhibited excellent effects as an undercoat when applying adhesive to EPDM or vinyl chloride resin. It turned out that it does.

Next, the adhesion of the coating film when the above-mentioned brimer compositions = 1 to 14 were used as an undercoat when coating the polyolefin polymer base material was measured by the following method.

EPDM consisting of each component shown in Table 1 above was heated at 160°C.
Each of the l0XIQX2 Ryatsu test pieces obtained by vulcanization treatment for 30 minutes was dipped in the primer compositions of Examples 1 to 14, and after air-drying at room temperature for 30 minutes, a urethane compound having the composition shown in Table 6 was prepared. A urethane paint obtained by reacting the sample at 80° C. for 13 hours in dry nitrogen gas was applied to each test piece and cured at room temperature for 24 hours.

Thereafter, the adhesion of the urethane coating formed on the surface of each test piece was examined by a cross-cut test, and it was found that all had sufficient adhesion.

(100 wl OO) The compositions of Comparative Examples 1 to 9 below are conventionally used as primer coating agents for polyolefin polymers.

Comparative Example 1 A composition was prepared by diluting Besokosol J-534J (manufactured by Dainippon Ink & Chemicals, Co., Ltd., linseed oil-modified long oil alkyd resin) with a mineral base, and further adding cobalt naphthenate as a desiccant.

Comparative Example-2 "Ester Resin-20" (manufactured by Toyobo Co., Ltd., saturated polyester resin) was mixed with methyl ethyl ketone/toluene = 1/
A composition diluted with a mixed solvent of 9 (weight ratio) was prepared.

Comparative Example 3 A composition was prepared by diluting Vinyrite-VMCHJ (manufactured by Union Carbide, vinyl chloride vinyl acetate copolymer) with a mixed solvent of methyl ethyl ketone/toluene = 1/1 (weight ratio).

Comparative Example 4 A composition was prepared by diluting S-LEC BM-2J (manufactured by Block Chemical Co., Ltd., butyral resin) with a mixed solvent of butanol/xylene = 1/1 (weight ratio).

Comparative Example 5 A composition was prepared by diluting OLESTAR M55-80AJ (manufactured by Mitsui Toatsu Co., Ltd., a moisture-curing polyurethane resin) with toluene.

Comparative Example-6 “Desmofene-100J (manufactured by Bayer AG, polyhydroxy compound) and “Desmodur-R” (manufactured by Bayer AG, polyhydroxy compound)
A composition was prepared by diluting a mixture of 1/1.5 (weight ratio) of polyisocyanate with a mixed solvent of methylene glycol/butyl acetate/ethyl acetate/toluene = 1/1/1/1 (weight ratio). .

Comparative Example-7 4/1 of "Beccosol J-524j (manufactured by Dainippon Ink & Chemicals, Ltd., linseed oil-modified long oil alkyd resin)" and "Super Beckamin J-820" (manufactured by the same company, butylated melamine resin) A composition was prepared by diluting the mixture with Kijirol.

Comparative Example-8 [Acryloid C-110VJ (manufactured by Rohm & Haas, thermoplastic acrylic resin] and nitrocellulose 9
A composition was prepared by diluting the 971 mixture with toluene.

Comparative Example-9 A 4/1 mixture of Acrydic 47-712J (manufactured by Dainippon Ink & Chemicals, thermosetting acrylic resin) and Super Beckamine 47-508J was diluted with a mixed solvent of toluene and butyl acetate. A composition was prepared.

Next, each of the compositions of Comparative Examples 1 to 9 was applied to the base material made of EPDM, and the urethane paint was applied thereon and cured for 24 hours. The adhesion of all coatings was found to be extremely weak.

(0/100) From the above test results, the above Examples-1 to
It was found that all of the 14 primer compositions exhibited excellent effects as an undercoat when coating a paint on a substrate made of EPDM.

Next, a usage example will be described in which the primer compositions of the above-mentioned Examples are used as an undercoat when coating paints and adhesives on various rubber products for automobiles.

Usage example = l: Door weather strip EPDM is often used in door weather strips that seal the gap between the vehicle body and the door.

Therefore, the primer composition of Example 1 was applied to the surface of a weatherstrip base material made of EPDM, and a urethane paint having the composition shown in Table 6 was applied thereon, and after air-drying at room temperature for 1 hour, Furthermore, a 5% by weight solution of dimethyl silicone oil (100,000 cSt) in toluene was applied.

Usage Example 2 EPDM is also widely used in the glass run used in the parts that slide against the window glass of Nigelas Land Assassins.

Therefore, the primer composition of Example 2 was applied to the surface of the glass run substrate made of EPDM, and the primer composition shown in the table above was applied thereon.
Apply urethane paint with the composition shown in 6 and apply urethane paint at room temperature.
It was air-dried for 4 hours.

Next, an abrasion resistance test was conducted on the coatings formed on the surfaces of the weather strip and glass run treated as described above in the following manner.

Test @: Kl type abrasion tester Test conditions: Friction element glass (thickness 5mm) Load
3 kg Friction element cycle 60 times/min Friction element stroke 145 Dragon test method: A part of the above weather strip and glass run was attached to a testing machine, and the coating surface was rubbed according to the test conditions.

As a result, no exposure of the base material was observed in any case even after repeated friction 50,000 times.

Furthermore, a 180° bending test was conducted to check the followability of each of the above coating films, and all of them showed extremely good followability, and EP
The flexibility and flexibility, which are the characteristics of DM, were not impaired in any way.

Next, the above abrasion resistance test was conducted using each of the primer compositions of Comparative Examples 1 to 9, which have been conventionally used as primer coatings for rubber. The base material was exposed due to repeated friction.

Usage Example 3: Electrostatic flocking product Nigrasran includes a product whose sliding surface with the window glass is electrostatically flocked using fibers.

The glass run base material was dipped in the primer composition of Example 3 and left to stand at room temperature for 30 minutes, and then the following urethane adhesive was applied to the surface, followed by nylon-
An electrostatic flocked product was obtained by electrostatically flocking a pile consisting of 66 short fibers and curing the urethane adhesive with hot air.

[Urethane adhesive]

A urethane adhesive was obtained by reacting the formulations shown in Table 7 at 80° C. for 3 hours in dry nitrogen gas.

Next, an abrasion resistance test of the coating film on the electrostatic flocked product treated as described above was conducted in the following manner.

Testing machine: Reciprocating type abrasion tester Test conditions: Friction element Glass (thickness 5) Friction element cycle 60 times/min Friction element stroke 145 Dragon Test method: Some of the above electrostatic flocking products were used in the testing machine After installation, the coating surface was rubbed according to the test conditions.

As a result, no exposure of the base material was observed even after 20,000 repetitions of friction.

It wasn't.

The brimer composition of the present invention can also be used for the following purposes.

Usage Example-4: Diaphragm In order to investigate the gasoline resistance of the NBR diaphragm base material coated with urethane paint after applying the primer composition of Example-4 and leaving it at room temperature for 30 minutes, the base material was placed at 24°C along with an untreated diaphragm. The sample was immersed in gasoline for 48 hours, and the mass change rate before and after immersion was measured using the following equation.

ΔW= ((wz ”Wl)/Wl) X 100
(%) (Wl is the mass before immersion, and W2 is the mass after immersion) As a result, the ΔW of the untreated diaphragm was 30%, while the ΔW of the treated diaphragm was 20%.
．． It was found that the primer composition of Example 4 was extremely effective in improving the gasoline resistance of the diaphragm base material.

Usage Example-5 Nibre cylinder cup In order to investigate the glycol resistance of the SBR brake cylinder cup base material, which was coated with the primer composition of Example-1 and left at room temperature for 30 minutes, and then coated with urethane paint, After immersing it together with the untreated brake cylinder cup body in commercially available low molecular weight ethylene glycol at 24°C for 1200 hours, the mass change rate ΔW before and after immersion was measured using the same method as for the diaphragm.

As a result, the Δ of the untreated brake cylinder cup body
W was 3.5%, whereas the ΔW of the treated product was reduced to 1.5%, indicating that the rubber composition was extremely effective in improving the glycol resistance of the brake cylinder cup body. It turned out that it shows.

Usage Example 5: Wiper Blade The primer composition of Example 2 was applied to the surface of an EPDM wiper blade, left at room temperature for 30 minutes, and the urethane paint shown in Table 6 was applied. A wiper blade with excellent followability and low frictional resistance during sliding was obtained.

From the above test results, it was found that the primer compositions of Examples 1 to 4 were extremely useful as undercoating agents when coating paints and adhesives on polyolefin vulcanized rubber.

Effects of the Invention As detailed above, the primer composition of the present invention exhibits the effect of exhibiting extremely strong adhesion to polyopine polymers, vinyl chloride resins, etc. This invention is extremely excellent as an undercoat when applying adhesives or paints to the surface of substrates made of various synthetic resins and rubbers.

[Brief explanation of drawings]

The figure is a cross-sectional view schematically showing a state in which a single layer of primer was formed on each end of two EPDM test pieces, and then the ends of both test pieces were joined via a chloroprene rubber adhesive. 1... One layer of primer, 2... Adhesive, 3... Test piece.

Claims (1)

[Claims] 1. A mixture consisting of (a) chloroprene rubber, (b) an acrylic monomer, (c) a Lewis acid, and (d) an organic solvent, based on 100 parts by weight of the solid content of the chloroprene rubber. and the acrylic monomer is 10-5
A primer composition which is mixed and polymerized in a proportion of 0.00 parts by weight. 2. The primer composition according to claim 1, wherein the acrylic monomer is at least one selected from acrylic acid, methacrylic acid, and derivatives thereof. 3. The Lewis acid is an inorganic acid, and is mixed in a proportion of 0.1 to 20 parts by weight based on 100 parts by weight of the solid content of the chloroprene rubber and the acrylic monomer. Primer composition according to item 1.