JPH0420605Y2 - - Google Patents

Description

[Detailed explanation of the idea]

The present invention relates to a laminate, and more particularly to a laminate in which a polyolefin resin layer and other layers are laminated via a specific adhesive composition. Conventionally, chloroprene-based or nitrile rubber-based adhesives have been used as adhesives for polyolefin resins such as polyethylene and polypropylene. These adhesives have relatively excellent adhesive properties, but in order to ensure excellent adhesive properties, it is necessary to treat the adhesive surface of the polyolefin resin with a mixture of chromic acid and concentrated sulfuric acid, Another problem is that it requires special treatment steps such as corona discharge treatment. Therefore, the present inventors investigated compositions that can bond polyolefin resin without special treatment, and found that a composition containing a specific compound does not require a treatment process on the surface of polyolefin resin. It was discovered that it has extremely good adhesive properties, and based on this knowledge, the present invention was completed. In other words, the present invention consists of () polyolefin resin;
() Liquid diene polymer containing active hydrogen groups (hereinafter referred to as
(A) It is called component. ), an adhesive composition comprising a polyisocyanate compound (hereinafter referred to as component (B)) and a bituminous substance (hereinafter referred to as component (C)), and ()
It is a laminate made of polyolefin resin or cotton cloth. In the laminate of the present invention, the active hydrogen group-containing liquid diene polymer, which is component (A) of the adhesive composition, is
The number average molecular weight is 300 to 25,000, preferably 500 to 25,000, and has active hydrogen groups such as hydroxyl, amino, imino, carboxyl, and mercapto groups at the end of the molecule.
10,000 liquid diene polymer. These liquid diene polymers include diene polymers having 4 to 12 carbon atoms, diene copolymers, and copolymers of these diene monomers and α-olefinic addition polymer monomers having 2 to 22 carbon atoms. and so on. Specific examples include butadiene homopolymer, isoprene homopolymer, butadiene-styrene copolymer, butadiene-isoprene copolymer, butadiene-acrylonitrile copolymer, butadiene-2-ethylhexyl acrylate copolymer, butadiene-n-octadecyl acrylate copolymer, and the like. Next, the adhesive composition for the laminate of the present invention is
The polyisocyanate compound of component (B) is an organic compound having two or more isocyanate groups in one molecule, and is an organic compound that has two or more isocyanate groups in one molecule, and is Contains reactive isocyanate groups. Such polyisocyanate compounds are well known, and may be in the form of a prepolymer having isocyanate groups at the ends obtained by reacting a polyol and a polyisocyanate in advance. Examples of polyisocyanate compounds include:
Mention may be made of the usual aromatic, aliphatic and cycloaliphatic ones, such as tolylene diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, liquid modified diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate, xylylene diisocyanate, Cyclohexyl diisocyanate, cyclohexane phelene diisocyanate, naphthalene
Examples include 1,5-diisocyanate, isopropylbenzene-2,4-diisocyanate, and addition reaction products of polypropylene glycol and tolylene diisocyanate. In addition, in the laminate of the present invention, the bituminous substance that is component (C) of the adhesive composition is not particularly limited, and examples thereof include straight asphalt, semi-brown asphalt, blown asphalt, or a mixture thereof, and preferably processed In addition, straight asphalt, which does not require high temperatures, or straight asphalt and other asphalt should be used in combination. The adhesive composition in the laminate of the present invention is as described above.
Consists of components (A), (B), and (C), and there are no particular restrictions on their blending amounts, but the equivalent ratio of the isocyanate groups contained in component (B) to the active hydrogen groups contained in component (A) is The selection should be such that groups/active hydrogen groups=1 to 20, preferably 2 to 5. When this equivalent ratio is less than 1, the viscosity becomes very high, and when it exceeds 20, the moisture curing rate is slow and foaming is likely to occur during curing. In addition, from the viewpoint of adhesion, the amount of component (C) is the sum of the amounts of component (A) and component (C).
In terms of parts by weight, it is 50 to 90 parts by weight, preferably 70 to 90 parts by weight.
It should be 85 parts by weight. The adhesive composition for the laminate of the present invention basically consists of the above three components, but other additives can be added as necessary. For example, to improve the physical properties of the composition, 1,4-butanediol, trimethylolpropane, ethylene glycol, a 3-mole ethylene oxide adduct of bisphenol A, N,N-bis(2-hydroxypropyl)aniline, etc. are added. be able to. In addition, plasticizers such as dioctyl phthalate, aromatic, naphthenic, and paraffinic softeners are added as viscosity modifiers, tackifying resins are added to adjust adhesive strength, and carbon black and calcium carbonate are also added. , fillers such as clay and talc, and various stabilizers can also be added. Examples of the tackifying resin include alkylphenol resins, terpene resins, terpenephenol resins, xylene formaldehyde resins, rosins, hydrogenated rosins, coumaron resins, aliphatic and aromatic petroleum resins, and the like. In addition, benzoyl chloride is used as a storage stabilizer, dibutyltin dilaurate, stannous octoate, and polyethylene diamine are used as curing accelerators, benzoyl chloride is used as a storage stabilizer, anti-aging agent is used to improve weather resistance, and silicone is used as an antifoaming agent. Compounds etc. can be added. By mixing and kneading the above raw materials, the adhesive composition for the laminate of the present invention can be obtained. The kneading may be carried out in the usual direction, for example, by melt-kneading using a Banbury mixer or the like at 0 to 120°C, preferably 10 to 90°C, for 0.5 to 48 hours, preferably 6 to 16 hours. can be done. Preferably, the active hydrogen group-containing liquid diene polymer and the bituminous material are heated and stirred, then cooled, and then the heated and melted polyisocyanate compound is added, kneaded, and cooled to form the adhesive composition for the laminate of the present invention. obtain. The adhesive composition in the laminate of the present invention is a moisture-curable prepolymer, and is thought to form a urea bond with moisture in the air and polymerize into a cured product. The adhesive composition thus obtained is used as an intermediate layer in the laminate of the present invention, and exhibits good adhesion when simply applied to the polyolefin resin without any special treatment. Therefore, this adhesive composition is particularly suitable for adhesion of polyolefin resins. Here, the polyolefin resin is not particularly limited, and various types may be mentioned. Specifically, polyethylene, crosslinked polyethylene, polypropylene,
Examples include ethylene-propylene copolymer. When using the adhesive composition in the laminate of the present invention, a prepolymer is prepared from the composition, and the prepolymer is used alone or if necessary mixed with an appropriate solvent such as toluene or xylene, and then used with a spray gun, brush, etc. It may be applied to the polyolefin resin as a target object using a roll coater, a flow coater, or the like. Although there are various materials that can be bonded to the polyolefin resin via the adhesive composition in the laminate of the present invention, polyolefin resin and cotton cloth are particularly suitable. When a polyolefin resin is used here, it may be the same as those mentioned above, or it may be different. The laminate of the present invention can be obtained by simply applying the adhesive composition to the surface of the polyolefin resin () and/or polyolefin resin or cotton cloth (), overlapping the two through the coated surfaces, and then exposing the adhesive composition to the atmosphere. When left to stand, the coated surface forms a hardened adhesive layer due to atmospheric moisture. According to the present invention, polyolefin resins or polyolefin resins and cotton cloth can be bonded to each other in good condition without performing any special surface treatment on the polyolefin resins. Moreover, in the laminate of the present invention, each layer is firmly adhered, especially in a low-temperature environment. Next, the present invention will be explained in more detail with reference to examples. Examples 1 to 3 A predetermined amount of each component shown in Table 1 was collected in a parallable flask, heated and stirred at 80° C. for 1 hour, dehydrated, and then cooled to room temperature. While maintaining the temperature at room temperature, a predetermined amount of 4,4'-diphenylmethane diisocyanate shown in Table 1 which had been heated and melted at 80 DEG C. was added with vigorous stirring, and the mixture was maintained at room temperature for about 4 hours. Next, the mixture was heated and stirred at 80° C. for 3 hours to cause a sufficient reaction and obtain a prepolymer. The obtained prepolymer was applied to the surface of the polyolefin resin sheet shown in Table 1, and a cotton canvas was placed on top of it for 25 minutes.
The adhesive strength was measured after being left for two weeks in an environment of 60% humidity and temperature. The results are shown in Table 1. Note that for Example 1, the adhesive strength at each temperature is shown in FIG. Comparative Example 1 After the surface of a polyethylene resin sheet was treated with a mixture of dichromic acid and concentrated sulfuric acid, a chloroprene adhesive was applied to the surface of the sheet, a cotton canvas was placed on top of this, and the sheet was heated at 25°C and 60% humidity. After being left in the environment for two weeks, the adhesive strength was measured. The results are shown in Table 1. Comparative Example 2 Adhesive strength was measured in the same manner as in Comparative Example 1 except that a polypropylene resin sheet was used as the polyolefin resin sheet and a nitrile rubber adhesive was used. The results are shown in Table 1.

【table】

【table】 [Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view showing one embodiment of the laminate of the present invention. In the figure, 1 is polyolefin resin,
2 represents an adhesive composition, and 3 represents a cotton canvas or polyolefin resin. FIG. 2 is a graph showing the relationship between the adhesive force between the polyethylene sheet and the adhesive layer obtained in Example 1 and the temperature.

Claims (1)

[Claims for Utility Model Registration] (1) () An adhesive composition consisting of a polyolefin resin, () a liquid diene polymer containing active hydrogen groups, a polyisocyanate compound, and a bituminous substance, and () a laminate consisting of a polyolefin resin or cotton fabric. body. (2) The laminate according to claim 1, wherein the amount of the polyisocyanate compound is such that the isocyanate group/active hydrogen group (equivalent ratio) = 1 to 20. (3) The laminate according to claim 1, wherein the polyolefin resin is polyethylene or polypropylene.