JPH0261907B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to polyolefin resin adhesives, which can be used for piping materials such as pipes, pulp and tanks, household goods such as containers, miscellaneous goods such as toys, industrial goods such as light electrical equipment, and automobile parts; Widely used as packaging material for films, etc. [Prior art and its problems] Compared to other thermoplastic resins, polyolefin resin has excellent impact resistance, chemical resistance, water resistance, wide frequency characteristics,
Although it has excellent properties such as permeation resistance, it generally has low affinity with adhesives and cannot be firmly bonded as it is. Therefore, in order to improve the adhesive strength, pre-treatments such as sanding treatment and nitric acid treatment are performed. However, the current situation is that, except for special or expensive epoxy resin adhesives, sufficient adhesive strength is not obtained, especially at high temperatures. [Object of the Invention] The object of the present invention is to apply optimal surface treatment to polyolefin resin and to use an inexpensive adhesive.
The object of the present invention is to obtain a polyolefin resin adhesive that is firmly bonded even at .degree. [Configuration of the Invention] The present invention provides sulfuric acid-dichromate treatment or solvent-
This is a polyolefin resin bonded body made by bonding a flame-treated polyolefin resin and an adherend with an adhesive containing an unsaturated polyester resin and an isocyanate compound. In order to solve the problems of the prior art described above, the present inventors applied various surface treatments such as sanding treatment, nitric acid treatment, and ultraviolet treatment to polyolefin resin, and then adhered it with various adhesives. Although many studies have been conducted to bond the material to the body, no matter what kind of adhesive is used in combination with these surface treatments, it has not been possible to achieve a strong bond, especially at high temperatures. Furthermore, as a result of extensive research, we found that by bonding a polyolefin resin treated with sulfuric acid-dichromate or solvent-flame to an adherend using an adhesive containing an unsaturated polyester resin and an isocyanate compound. Surprisingly, it has been discovered that a polyolefin resin adhesive that is extremely strongly bonded not only at room temperature but also at high temperatures can be obtained, and the present invention has been achieved. That is, the present invention is characterized in that a sulfuric acid-dichromate or solvent-flame treated polyolefin resin and an adherend are bonded together using an adhesive containing an unsaturated polyester resin and an isocyanate compound. This invention relates to a polyolefin resin adhesive. Its embodiments are as described in the claims. [Specific explanation of the structure of the invention] In the present invention, sulfuric acid is added to the polyolefin resin.
The combination of dichromate treatment or solvent-flame treatment and the use of an adhesive containing an unsaturated polyester resin and an isocyanate compound is an essential requirement; even if one of these requirements is absent, the product remains strong. The bonded body cannot be obtained. Generally, sulfuric acid-dichromate treatment, solvent treatment, and flame treatment are known as surface treatment methods for polyolefin resin adhesives. However, examples in which polyolefin resin is subjected to sulfuric acid-dichromate treatment or solvent-flame treatment and bonded with an adhesive containing an unsaturated polyester resin and an isocyanate compound can also be used not only at room temperature but also as in the present invention. There are no examples of strong adhesive strength even at high temperatures. The sulfuric acid-dichromate treatment in the present invention is
Any method commonly used for plastics etc. may be used without particular limitation. The solvent-flame treatment in the present invention is a method in which a polyolefin resin is immersed in a solvent at an arbitrary temperature for 30 seconds or more and 4 hours or less, then dried and flame-treated. The solvent used in the present invention includes n-hexane, toluene, chloroform, trichlene, xylene, tetrachloroethylene, acetone, carbon tetrachloride, etc., which swell or dissolve the polyolefin resin. The flame treatment in the present invention is not particularly limited and may be any method commonly used for plastics and the like. Although the solvent treatment in the present invention is not particularly limited, even better effects can be obtained by irradiating with white sunlight or ultraviolet rays while immersing at a low temperature. The adhesive used in the present invention is a blend of an unsaturated polyester resin and an isocyanate compound, and the number of isocyanate groups in the compound is 0.5 to 30, more preferably 0.75 per 1 hydroxyl group in the resin.
It is best to mix up to 10 pieces. If the number of isocyanate groups in the compound is less than 0.5 or more than 30 per hydroxyl group in the resin, a strongly bonded polyolefin resin adhesive cannot be obtained. The adhesive used in the present invention contains peroxides such as methyl ethyl ketone peroxide and benzoyl peroxide as a curing agent to speed up the curing speed and sufficiently proceed with curing, and metal soaps such as cobalt naphthenate and manganese naphthenate as a curing accelerator. It is preferable to use the following. Further, fillers such as silica, talc, calcium carbonate, etc. may be added. The unsaturated polyester resin in the present invention is not particularly limited, and may be any ester compound of a polyhydric alcohol, an unsaturated polybasic acid, and a saturated polybasic acid. Alternatively, it may be dissolved in a monomer such as styrene that can be copolymerized with unsaturated bonds, and a polymerization inhibitor and other additives may be added thereto, if necessary. Further, the isocyanate compound is a compound having an isocyanate group in its molecule, preferably a compound having two or more isocyanate groups in one molecule. The compounds include 2,4-tolylene diisocyanate (hereinafter abbreviated as 2,4-TDI), 2,6-tolylene diisocyanate (hereinafter abbreviated as 2,6-TDI), diphenylmethane-4,
4-diisocyanate (hereinafter abbreviated as MDI), hexamethylene diisocyanate (hereinafter abbreviated as HMDI), trimer of HMDI, reaction product of 3 mol of HMDI and 1 mol of trimethylolpropane, triphenylmethane-4,4,4-triisocyanate, Tris −
(P-isocyanate phenyl) thiophosphate and the like. These can be used alone or in combination.
It is also preferable to use a mixture of more than one species, diluted with a solvent such as ethyl acetate or methylene chloride if necessary. Although the order of mixing the respective adhesive formulations is not particularly limited, it is preferable to mix the unsaturated polyester resin with which the curing accelerator has been mixed in advance and the isocyanate compound, and then add the curing agent. The polyolefin resins to which the sulfuric acid-dichromate treatment is applied in the present invention are high density polyethylene resin (hereinafter abbreviated as HDPE), medium density polyethylene resin (hereinafter abbreviated as MDPE), and low density polyethylene resin (hereinafter abbreviated as LDPE). , ultra-high molecular weight polyethylene resin (hereinafter abbreviated as UHMWPE), linear low-density polyethylene resin (hereinafter abbreviated as LLDPE), cross-linked polyethylene resin (hereinafter abbreviated as CRPE), polypropylene resin (hereinafter abbreviated as PP), polybutene resin, polymethyl Examples include pentene resin. Polyolefin resins to which solvent-flame treatment is applied include HDPE, MDPE, LDPE, UHMWPE,
Examples include LLDPE and CRPE. The above polyolefin resins can be used alone, and fillers such as glass fiber, aramid fiber, carbon fiber, and carbon black, pigments, etc.
It may be a polyolefin resin composition containing additives such as stabilizers. The adherends used in the present invention include HDPE,
MDPE, LDPE, UHMWPE, LLDPE, CRPE,
Polyolefin resins such as PP, polybutene resin, and polymethylpentene resin, chlorine-based resins such as polyvinyl chloride, chlorinated polyvinyl chloride, and polyvinylidene chloride, polyvinylidene fluoride (PVDF),
Polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (PCTFE), chlorotrifluoroethylene - Ethylene copolymer (ECTFE), tetrafluoroethylene-ethylene copolymer (ETFE), polyvinyl fluoride (PVF), polypylidene fluoride-hexafluoropropylene copolymer (PVDF)
-HEP), polyvinylidene fluoride-polychlorotrifluoroethylene copolymer (PVDF-
PCTFE) and other fluororesins, acrylonitrile
Styrene copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-vinyl alcohol copolymer resin, polystyrene resin, polyurethane resin, cellulose acetate resin, polyester resin such as polyethylene terephthalate, polybutylene terephthalate, nylon 6, nylon 66, Polyamide resins such as nylon 11, nylon 12, nylon 6 and 10, polycarbonate resins, polyphenylene oxide resins, polyphenylene sulfide resins, polyarylate resins, polysulfone resins, polyethersulfone resins, polyamideimide resins, polyimide resins , thermoplastic resins such as polyaramid resins, polyamino bismaleimide resins, aromatic polyester resins, polytriazine resins, polyether-etherketone resins, urea resins, melamine resins, phenolic resins, diallyl phthalate resins, unsaturated polyester resins, and epoxy resins. Alternatively, thermosetting resins, rolled steel, carbon steel, stainless steel, iron such as cast iron, aluminum and aluminum alloys, magnesium alloys, copper and copper alloys, nickel and nickel alloys, metals such as zinc, alumina perilia, magnesium, etc. sintered oxide,
Sintered carbides such as carbon, silicon, and boron carbide, and inorganic substances such as glass. When the adherend is a resin, those containing inorganic substances such as glass fiber, talc, iron powder, metals, etc. can also be preferably used. In addition, when the adherend is a fluororesin,
It is necessary to perform surface treatment such as flame treatment or metal sodium treatment. In addition, if the adherend is made of polyamide resin, polycarbonate resin, polyphenylene oxide resin, polyphenylene sulfide resin, etc., surface treatment such as flame treatment will provide stronger adhesive strength. A polyolefin resin adhesive body is obtained. Furthermore, if the adherend is metal, it is desirable to perform a conventional surface treatment such as acid treatment depending on the adherend. The shape of the polyolefin resin adhesive obtained in the present invention may be any shape, such as a pipe, tube, sheet, plate, film, cylinder, or square prism, and is not particularly limited. The method for manufacturing the polyolefin resin adhesive body in the present invention is not limited in any way, but it can be manufactured, for example, by the following method. The surface of the polyolefin resin molded product obtained by injection, extrusion, compression molding, etc. was treated in advance with sulfuric acid-dichromate or solvent-flame treatment, and the surface of the adherend was also subjected to conventional surface treatment as necessary. After that, an adhesive containing an unsaturated polyester resin and an isocyanate compound is applied to each adhering surface, and the two are overlapped and the adhesive is cured at room temperature or under heat to obtain a polyolefin resin adhesive, or, The surface of a polyolefin resin obtained in advance by injection, extrusion, compression molding, etc. is treated with sulfuric acid-dichromate or solvent-flame in a conventional manner, and then glass fibers are laminated while impregnated with an unsaturated polyester resin and cured. This bonded body of glass fiber reinforced resin and polyolefin resin is obtained. EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to these Examples in any way. Example 1 Sulfuric acid-dichromate mixture (weight ratio, 98% sulfuric acid:
water: potassium dichromate = 1200:120:75) to 90
Heat to ℃ and add HDPE plate (dimensions 3t x
25w x 100mm). After soaking for 1 hour,
After taking out the HDPE plate, washing it with water and drying it, attach it to a glass fiber reinforced unsaturated polyester resin (hereinafter abbreviated as FRP) plate (dimensions 3t x 25w x 100mm) using an adhesive having the composition shown below.
12.5mm width and 60℃ after adhesive as shown in Figure 2.
Polyolefin (HDPE) is heated and cured for 24 hours.
A bonded body was obtained. Γ Unsaturated polyester resin [Product name: U-Pica
4521PT: Manufactured by Nippon U-Pica Co., Ltd.] 100 parts Γ Isocyanate compound [HMDI trimer,
Product name Coronate EH: Nippon Polyurethane Industries
Co., Ltd.] 25 parts Γ Methyl ethyl ketone peroxide 55% dimethylene phthalate solution [Product name, Kayametsuku A: manufactured by Kayaku Nouri Co., Ltd.] (hereinafter abbreviated as MEKPO)
1.5 parts Γ 6% cobalt naphthenate solution (hereinafter referred to as Na-Co
0.5 part (abbreviated as ) 0.5 part FIG. 1 and FIG. 2 show a side view and a plan view, respectively, of the polyolefin adhesive body of the present invention,
Reference numeral 1 indicates a polyolefin resin plate, 2 indicates an adherend plate, and 3 indicates an adhesive portion. The bonded body obtained in this example was subjected to an adhesive strength test in accordance with JIS K6856 [Test method for bending adhesive strength of adhesives]. That is, as shown in Fig. 3, the adhesive body was supported on a support stand 4 having a support point with a width of 38 mm so that the adhesive part was located in the center of the support point, and then a load was applied to the adhesive part to conduct an adhesive strength test. I went. The radius of the tip of the load portion and each support point is 4 mm. Example 2 A polyolefin resin adhesive was obtained in the same manner as in Example 1, except that a UHMWPE plate was used instead of the HDPE plate used in Example 1. Example 3 Same as Example 1 except that an LDPE plate was used instead of the HDPE plate used in Example 1, and the temperature of the sulfuric acid-dichromate mixture used as the surface treatment liquid was changed from 90°C to 60°C. A polyolefin resin adhesive was obtained. Example 4 A polyolefin resin adhesive was obtained in the same manner as in Example 1. This was subjected to an adhesive strength test at a test atmosphere temperature of 120°C in accordance with JIS K6856 [Test method for bending adhesive strength of adhesives]. Example 5 An HDPE plate (dimensions: 3t x 25w x 100mm) is irradiated with white sunlight while being immersed in an n-hexane solution at 0°C for 4 hours. After that, let it air dry for 30 minutes and then burn the butane gas to create a flame (temperature 900~
1000℃) for ² seconds per 1cm2, and
A polyolefin resin adhesive was obtained by bonding an FRP plate (dimensions: 3t x 25w x 100mm) in the same manner as in Example 1. Examples 6 and 7 A polyolefin resin adhesive was obtained in the same manner as in Example 5, except that a trichlene solution and a chloroform solution were used instead of the n-hexane solution used in Example 5. Example 8 A polyolefin resin adhesive was obtained in the same manner as in Example 5. This was subjected to an adhesive strength test at a test atmosphere temperature of 120°C in accordance with JIS K6856 [Test method for bending adhesive strength of adhesives]. Examples 9 to 14 Polyolefin resin adhesive bodies were obtained in the same manner as in Example 1, except that adherends subjected to the surface treatments shown in Table 1 were used instead of the FRP plates in Example 1. Comparative Examples 1 to 3 The same method as in Example 1 was used except that the untreated polyolefin resin plate shown in Table 1 was used instead of the HDPE plate treated with the sulfuric acid-dichromate mixture used in Example 1. A polyolefin resin adhesive was obtained. Example 15 Sulfuric acid-dichromate mixture (weight ratio, 98% sulfuric acid:
water: potassium dichromate = 1200:120:75) to 90
HDPE pipe (outer diameter 60 mm,
53mm inner diameter, 50mm length). 1 hour later
After taking out the HDPE pipe and washing it with water and drying it, apply an adhesive consisting of the composition shown below, and leave it for 24 hours at 20℃.The glass fiber is then impregnated with unsaturated polyester resin (product name: U-Pica 4521PT, manufactured by Nippon U-Pica Co., Ltd.) to a length of 2 mm. Layer it horizontally to the thickness of , harden it at 60℃ for 24 hours,
An HDPE composite tube with FRP as the outer layer was obtained. this
A heat cycle test of 30 minutes each in 120°C air and 0°C water was repeated 20 times, but no peeling between HDPE and FRP was observed. Γ Unsaturated polyester resin [Product name: U-Pica
4521PT: Manufactured by Nippon U-Pica Co., Ltd.] 100 parts Γ Isocyanate compound [HMDI trimer,
Product name Coronate EH: Nippon Polyurethane Industries
Co., Ltd.] 25 parts Γ Methyl ethyl ketone peroxide 55%, dimethylene phthalate solution [Product name Kayametsuku A: manufactured by Kayaku Nouri Co., Ltd.] 1.5 parts Γ 6% cobalt naphthenate solution 0.5 parts Comparative Example 4 In Example 15 FRP was fabricated in the same manner as in Example 15, except that untreated HDPE pipe was used instead of HDPE pipe treated with sulfuric acid-dichromate mixture.
An HDPE composite tube with an outer layer of We conducted a heat cycle test of this in 100℃ air and 20℃ water for 30 minutes each, and found that HDPE and
FRP peeled off at the interface. Example 16 Even when a flat load of 170 kg was repeatedly applied 100,000 times to the EDPE composite pipe obtained in Example 15, no abnormality was observed. Comparative Example 5 When a flat load of 170 kg was applied to the HDPE composite pipe obtained in Comparative Example 4, peeling occurred at the first time. The adhesive strength test results of the polyolefin resin adhesive bodies obtained in the above Examples and Comparative Examples are summarized in Table 1.

【table】

〔Effect of the invention〕

According to the present invention, as shown in the examples, by using an adhesive prepared by applying sulfuric acid-dichromate treatment or solvent-flame treatment and blending unsaturated polyester resin and isocyanate compound, It is possible to obtain a polyolefin resin adhesive that is firmly bonded even at high temperatures such as 120°C. In the FRP-coated HDPE composite pipe obtained by the present invention, no peeling of the adhesive surface occurs even under heat cycles between 120°C and 0°C. In addition, no abnormality was observed even after flattening was repeated 100,000 times with a load of 3/4 of the short-term flattening failure load.
It can be used satisfactorily even under such harsh conditions. Furthermore, depending on the application, the surface is made of polyolefin resin that has excellent properties such as impact resistance, chemical resistance, and water resistance, and the back surface or base is made of metal or various types of plastic, making the overall heat resistant. A polyolefin resin adhesive body having excellent physical properties such as dimensional stability, creep resistance, mechanical strength, and cushioning properties can be obtained.

[Brief explanation of drawings]

1 and 2 show an example of the polyolefin adhesive of the present invention, FIG. 1 is a side view, FIG. 2 is a plan view, and FIG.
It is a figure for explaining the test method of the adhesive strength of the adhesive body shown in a figure. DESCRIPTION OF SYMBOLS 1... Polyolefin resin plate, 2... Adherent, 3... Adhesive part, 4... Support base, 5... Support body, 6... Load part.

Claims (1)

[Claims] 1. A polyolefin resin that has been treated with sulfuric acid-dichromate or solvent-flame and adhered to an adherend using an adhesive containing an unsaturated polyester resin and an isocyanate compound. Characteristic polyolefin resin adhesive. 2 Hydroxyl group of unsaturated polyester resin as adhesive 1
2. The polyolefin resin adhesive according to claim 1, wherein both are blended so that the number of isocyanate groups in the isocyanate compound is 0.5 to 30. 3 Polyolefin resin treated with sulfuric acid-dichromate can be used as high-density polyethylene resin, medium-density polyethylene resin, low-density polyethylene resin, ultra-high molecular weight polyethylene resin, linear low-density polyethylene resin, cross-linked polyethylene resin, polypropylene resin, polybutene resin The polyolefin resin adhesive according to claim 1 or 2, which is a polymethylpentene resin. 4. Claim 1, wherein the solvent-flame-treated polyolefin resin is a high-density polyethylene resin, a medium-density polyethylene resin, a low-density polyethylene resin, an ultra-high molecular weight polyethylene resin, a linear low-density polyethylene resin, or a crosslinked polyethylene resin. Or the polyolefin resin adhesive body according to item 2. 5. The polyolefin resin adhesive according to claim 1, 2, or 4, wherein the solvent is n-hexane, toluene, chloroform, trichlene, xylene, tetrachloroethylene, acetone, or carbon tetrachloride. 6. Claims 1, 2, 3, 4, or 5, wherein the adherend is a thermoplastic resin, a thermosetting resin, a metal, an inorganic substance, or a mixture thereof. Polyolefin resin adhesive.