JPH0322897B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a primer for polyolefin resins.

More specifically, in the presence of a tertiary phosphine, carbon dioxide gas is blown into an isocyanate compound at a reaction temperature of -70°C to 150°C, and the reaction is carried out for 30 to 10 hours. Coating of polyolefin resin molded product containing an adduct of polyhydroxypolyolefin and isocyanate having an oxadiazine-2,4,6-trione ring (hereinafter simply referred to as oxadiazinetrione ring or trione ring), polyolefin resin This invention relates to a primer useful for adhesion between molded products or for adhesion between polyolefin resin molded products and other materials.

Generally, the surface of polyolefin resin molded products such as polyethylene or polypropylene has poor adhesion to paints and adhesives, so the surface of the resin is modified by electrically or chemically oxidizing it. A method of improving adhesion or a method of undercoating with various primer components to improve adhesion has been adopted. Known examples of such primers include polyethyleneimine compounds and isocyanate compounds. However, in many cases, this effect only appears in combination with specific adhesives.
Furthermore, the effects are not necessarily satisfactory.

An object of the present invention is to provide a primer for polyolefin resin that provides excellent adhesion and peeling resistance.

That is, the present invention provides a 1,3,5 compound obtained by blowing carbon dioxide gas into an isocyanate compound in the presence of a tertiary phosphine at a reaction temperature of -70°C to 150°C and reacting for 30 to 10 hours. - A primer for a polyolefin resin containing an adduct of an isocyanate having an oxadiazine-2,4,6-trione ring and a polyhydroxypolyolefin.

The isocyanate having an oxadiazinetrione ring, which is an isocyanate component used in producing the adduct used as a primer component in the present invention, means a compound having both an oxadiazinetrione ring and an isocyanate group in the molecule. Such compounds can be produced by reaction of isocyanate compounds with carbon dioxide. Examples of raw material isocyanate compounds include tetramethylene diisocyanate, hexamethylene diisocyanate, ω,ω'-diisocyanatodipropyl ether, 2,6-diisocyanatocaproic acid ester, 1,6,11-tripropyl ether, Isocyanatoundecane, bis(isocyanatomethyl)cyclohexane, bis(isocyanatoethyl)cyclohexane, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane, bis(4-isocyanatocyclohexyl)methane, xylene Aliphatic, alicyclic, and araliphatic polyisocyanate compounds such as diisocyanate and bis(2-isocyanatoethyl)benzene are used. These polyisocyanate compounds may be used alone or in mixtures with each other. Also, monoisocyanate compounds such as methyl isocyanate, ethyl isocyanate, n-
It can be used by mixing and reacting with butyl isocyanate, ω-chlorohexyl isocyanate, cyclohexyl isocyanate, cyclohexylmethyl isocyanate, benzyl isocyanate, phenylethyl isocyanate, and the like. Also,
It may be a dimer or trimer of the polyisocyanate compound. The reaction between the polyisocyanate compound and carbon dioxide is carried out in the presence of a catalyst, and tertiary phosphines are effective as the catalyst. The reaction is generally carried out by blowing carbon dioxide gas into the reaction system of the isocyanate compound and the catalyst. The reaction temperature is usually -70~150℃, especially -20~70℃
°C is preferred. Such a reaction usually yields a mixture of isocyanates having one to several oxadiazitrione rings. The reaction completes in about 30 minutes to 10 hours, depending on the amount of catalyst. After the reaction, unreacted carbon dioxide can be removed while blowing nitrogen gas under heating, and unreacted isocyanate compounds can be removed by conventional methods such as distillation and extraction. After the reaction, various compounds are usually added to completely stop the reaction and to preserve the product stably.
As stabilizers, alkylating agents, acylating agents, acids, ester derivatives, phenols, peroxides, sulfur, polysulfides, metal sulfides, halogens, and the like can be used.

Such isocyanate having an oxadiazinetrione ring is usually a mixture of isocyanates having 1 to 3 trione rings, and this mixture can be used as it is as an isocyanate component in producing the adduct of the present invention. Moreover, this isocyanate component may contain unreacted isocyanate.

The adduct used as a primer component in the present invention can be produced by reacting an isocyanate having a trione ring as described above with a polyhydroxypolyolefin. The polyhydroxy polyolefin as used in the present invention is a saturated or partially saturated hydrocarbon polymer having at least one hydroxyl group at the end of the main chain. Such polyhydroxypolyolefins have molecular weight
500 to 200,000 polymers that are liquid, semisolid, and solid at room temperature (average number of hydroxyl groups per molecule is 1.5 to 8.0).

Such polyhydroxy polyolefins are
For example, using diene as a raw material, Telekerik (Telekerik)
-chelic) Diene polymers and/or diene copolymers produced by radical polymerization, anionic polymerization (living polymerization), etc., which are conventionally employed as polymer synthesis methods, are usually obtained by hydrogenating them. It will be done. Furthermore, such polyhydroxypolyolefin can be obtained by oxidizing and decomposing a copolymer of α-olefin and other monomers.
It can also be obtained by subsequent reduction. Examples of such polyhydroxypolyolefins include Polyether-H (manufactured by Mitsubishi Chemical Industries, Ltd.), and those having a molecular weight of 500 to 5,000 can be suitably used. To produce an adduct by reacting such a polyhydroxy polyolefin with the above trione ring-containing isocyanate,
It can be produced using normal urethanization reaction conditions so that the NCO/OH ratio is approximately 0.1 to 5.

In a preferred embodiment of the present invention, a solution primer is used in which an adduct of an isocyanate having an oxadiazinetrione ring and a polyhydroxypolyolefin is dissolved in the isocyanate in an inert solvent. Such solvents include, for example, ketones such as acetone, methyl ethyl ketone, aromatic hydrocarbons such as toluene, xylene, halogenated saturated or unsaturated solvents such as methylene chloride, trichloromethane, trichloroethane, trichloroethylene, etc. or fatty acid esters such as ethyl acetate and butyl acetate. The concentration of the adduct when used as a solution is
It is preferably 0.1 to 50% by weight.

The primer of the present invention may be further added with a viscosity modifier, a filler, a dispersion stabilizer, etc., if necessary.

Paints and adhesives that can be used in combination with the primer of the present invention include those conventionally used as polyolefin resin paints and adhesives, such as epoxy resin-based, polyurethane-based, acrylic-based, and polyolefin-based paints. There is an adhesive.

Among these, the primer of the present invention is a polyolefin adhesive [a hot melt adhesive based on an ethylene-vinyl acetate copolymer (vinyl acetate content: 5 to 50% by weight) and its saponified product or a carboxyl modified product thereof; Takemelt series; Takemelt M-205, Takemelt M-
207 manufactured by Takeda Pharmaceutical Co., Ltd.].

Polyolefin resins to which the primer of the present invention is applied include polyethylene (LDPE, HDPE
), polypropylene or cross-linked polyethylene, and can be widely applied to coating these molded products, adhering these molded products to each other, or adhering these molded products to different materials. be.

When painting or adhering a polyolefin resin using the primer of the present invention, the primer composition is first applied to the surface of the resin to be painted or adhered, and the primer composition is usually dried at room temperature. The primer of the present invention does not lose its effectiveness as a primer even if it is left for a while after drying. This point is one of the advantages when compared with conventional isocyanate-based primers.

For this coating method, ordinary coating methods such as dipping, spraying, and brushing can be appropriately employed. The coating amount is approximately 0.5g/m ² to 100 in terms of adducts.
g/ ^m2 . Then, a paint or an adhesive is applied on the primer coating film formed by the above operation, and a similarly primed resin or other different material is overlaid to complete the adhesion.

Materials primed with the primer of the present invention exhibit excellent adhesive strength after adhesion, and provide coatings that do not peel off after painting.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples, but these are not intended to limit the present invention in any way.

Reference example 1 40 for 841g of hexamethylene diisocyanate
1.8 g of tri-n-butylphosphine was added while blowing carbon dioxide gas at °C, and the reaction was carried out for 6 hours with stirring. The supply of carbon dioxide gas was stopped, 0.3 g of sulfur powder was added, and the mixture was stirred for 30 minutes and then cooled. When the raw material was removed from this material using a thin film evaporator, 255 g of a pale yellow, slightly viscous liquid was obtained. This thing is
It has an NCO content of 4.78meq/g, an oxadiazinetrione content of 2.77meq/g, and a residual monomer amount of 0.4
%.

Reference Example 2 3.0 g of tri-n-butylphosphine was added to 971 g of 1,3-bis(isocyanatomethyl)cyclohexane at 10°C while blowing carbon dioxide gas, and the reaction was carried out for 5 hours while stirring. Replace the carbon dioxide supply with nitrogen and add 3.8g of benzoyl peroxide to 80
Stir for a minute. When the raw material was removed by evaporation of the product using a thin film evaporator, 280 g of a pale yellow viscous liquid was obtained. This product has an NCO content of 4.35 meq/g, an oxadiazinetrione content of 2.22 meq/g, and a residual monomer content of 0.8%.

Reference example 3 1,3-bis(isocyanatomethyl)cyclohexane 194g and tri-n-butylphosphine 2.0g
A reaction was carried out for 8 hours in the same manner as in Reference Example 2 using
The reaction was stopped using 2.6 g of benzoyl peroxide.
The product was dissolved in 100 ml of toluene, 500 ml of n-hexane was added thereto, and the solution was thoroughly shaken to remove the solvent layer. After repeating this extraction operation three times in total, butyl acetate was added to the extraction residue to reduce the nonvolatile content to 85%.
% solution. The NCO content of this thing is
2.60meq/g, oxadiazinetrione content is
It is 2.27meq/g.

Reference Example 4 22 g of the isocyanate component having an oxadiazinetrione ring obtained in Reference Example 1 and polyhydroxypolyolefin (Polyether H, hydroxyl value 44
(manufactured by Mitsubishi Kasei Corporation), 50 ml of toluene, and 3 mg of dibutyltin dilaurate were reacted at 70°C for 3 hours with stirring to obtain an adduct having an NCO content of 0.76 meq/g and an oxadiazinetrione content of 0.6 meq/g. I got it.

Infrared absorption spectrum and NMR of this product
It was found that a product with a urethane bond and an oxadiazinetrione ring could be obtained from the sputum.

Example 1 10.7 g of the adduct obtained in Reference Example 4 was added to toluene.
A primer solution was obtained by dissolving 109 g of the primer. commercially available
LDPE (Mirason B-53 Mitsui Polychemical Co., Ltd.)
Two sheets with a thickness of 1 mm were prepared from a commercially available product (manufactured by J.D. Co., Ltd.), and the above primer solution was applied with a brush onto the adhesive surface of each sheet, followed by drying at room temperature. A 100μ thick film of modified polyolefin hot melt adhesive (Takemelt M-205, manufactured by Takeda Pharmaceutical Company, Ltd.) was sandwiched between the coated surfaces in the shape of a sandwich.
Bonding was carried out using contact pressure at 110°C for 15 minutes. The adhesive test piece thus obtained was subjected to the JISK6854 test method.
When the T-peel strength was measured, it showed a value of 10.3 Kg/cm.

As a comparative example, the above primer was not applied.
An adhesive test piece was prepared in the same manner using an LDPE sheet, and the T-peel strength was measured, and it was found to be 1.6.
Only Kg/cm values were available.

Further, as a comparative example, a liquid moisture-curing urethane resin (Takenate M-402 manufactured by Takeda Pharmaceutical Company Limited) was used as the isocyanate component of the above primer, and a primer solution diluted with ethyl acetate and having a solid content of 3% was used. An adhesive test piece was prepared in the same manner as in the example except that the T-peel strength was measured, and a value of only 2.5 kg/cm was obtained.

Example 2 Two sheets with a thickness of 1 mm were made from commercially available HDPE (HIZEX 6300M manufactured by Mitsui Petrochemical Industries, Ltd.), and the primer solution obtained in Example 1 was brushed onto the adhesive surface of each sheet. and dried at room temperature. A modified polyolefin hot melt adhesive (Takemelt M-207) between the coated surfaces
A film with a thickness of 100 μm (manufactured by Takeda Pharmaceutical Company, Ltd.) was sandwiched in a sandwich shape, and the film was pressed with contact pressure at 110° C. for 15 minutes. The adhesive test piece obtained in this way was
When the T-peel strength was measured according to the JISK6854 test method, it showed a value of 11.5 kg/cm.

As a comparative example, the above primer was not applied.
Using an HDPE sheet, an adhesive test piece was prepared in the same manner, and the T-peel strength was measured, and it was found to be 1.6
Only Kg/cm values were available.

Example 3 The primer solution obtained in Example 1 was applied with a brush to the adhesive surface of a 1 mm thick electron beam cross-linked polyethylene sheet and the adhesive surface of a 1.6 mm thick iron plate (cold rolled steel plate), and the mixture was heated at room temperature. Dry. A 100μ thick film of modified polyolefin hot melt adhesive (Takemelt M-205, manufactured by Takeda Pharmaceutical Co., Ltd.) was sandwiched between the coated surfaces in the shape of a sandwich.
Bonding was carried out using contact pressure at 150°C for 15 minutes. When the 180° peel strength of this adhesive test piece was measured according to the JSK6854 test method, it showed a value of 21.5 kg/inch.

As a comparative example, an adhesive test piece was prepared without applying the primer obtained in Example 1 to the above test piece, and the 180° peel strength was measured, and it was found to be 11.5 kg/
Indicates the value of inch.

Claims (1)

[Claims] 1 In the presence of tertiary phosphines, the reaction temperature -
1,3,5-oxadiazine-2, obtained by blowing carbon dioxide gas into an isocyanate compound at 70°C to 150°C and reacting for 30 minutes to 10 hours.
A primer for a polyolefin resin containing an adduct of an isocyanate having a 4,6-trione ring and a polyhydroxypolyolefin.