JPH0136873B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field The present invention relates to a polyurethane resin adhesive, more specifically, an organic solution type adhesive which has excellent initial adhesive strength especially when at least one of the adherends is a sheet, film or foam of soft polyvinyl chloride. The present invention relates to a polyurethane resin adhesive that exhibits high properties and enables adhesive application on one side. Conventional technology and problems to be solved Conventionally, solution-type polyurethane adhesives have excellent flexibility and plasticizer resistance, so they have been used to make polyvinyl chloride sheets, films, or foams containing a large amount of plasticizer. It is used in a wide range of applications as a universal adhesive to bond molded products to other plastic materials, wood, metal, etc. However, it has been desired to develop an adhesive that can prevent adhesive deterioration due to plasticizers migrating from the adherend to the adhesive interface, has excellent heat resistance, and has improved performance. On the other hand, such solvent-based adhesives made of urethane rubber have poor adhesive strength, and during the bonding process, the adhesive is applied to both surfaces of the adherend, and after an open time for the solvent to dry, both surfaces are bonded. Superimpose the
It required compression and temporary fixing until adhesive strength was developed. The present inventors conducted intensive research to develop an adhesive that is less affected by plasticizers contained in adherends, and found that they dissolved thermoplastic polyester urethane rubber in an organic solvent and added monomers for acrylic resin to the rubber. We have developed a polyurethane adhesive with excellent plasticizer adhesion, which is made by blending the main adhesive component with chlorinated rubber and an isocyanate compound as a crosslinking agent. The application is pending (see Japanese Patent Application No. 58-201499). The inventors of the present invention further investigated the developed adhesive and found that if a specific rosin resin or rosin resin derivative is added to the main component of the adhesive, initial adhesion to plasticizer-containing soft polyvinyl chloride materials can be improved. It was discovered that the adhesive strength was further improved, and that even if the clamping conditions were reduced, sufficient adhesion could be maintained with single-sided coating without the need for temporary fixing, and that it was possible to use thermoplastic polyester urethane rubber that did not graft. , we have completed the present invention. That is, the present invention provides thermoplastic polyester urethane rubber (hereinafter referred to as urethane rubber) and/or
or urethane rubber grafted with at least one member selected from the group of acrylic acid, acrylic ester, methacrylic acid, and methacrylic ester (hereinafter referred to as graft rubber), rosin resin and/or rosin resin derivative, chlorinated The present invention provides a polyurethane resin adhesive characterized by comprising a rubber, an organic solvent, and an isocyanate compound as a crosslinking agent. Structure and Effects of the Invention The urethane rubber that can be used as a component in the present invention is an elastomer having urethane bonds in its molecular chain, and usually includes polybasic acids (terephthalic acid, isophthalic acid, phthalic acid, succinic acid, adipic acid). , azelaic acid, sebacic acid, etc.) and dihydric alcohols (ethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-
hexanediol, diethylene glycol, triethylene glycol, polyethylene glycol,
Propylene glycol, etc.) are subjected to a condensation reaction, and the obtained saturated polyester resin having terminal hydroxyl groups is combined with the active hydrogen groups and diisocyanate compounds (tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, etc.).
It is a linear polymer that has been reacted with the isocyanate groups of cyclohexylmethane diisocyanate, etc. in approximately equivalent amounts. In the present invention, a monomer to be grafted onto the urethane rubber (hereinafter referred to as a graft monomer)
is acrylic acid, acrylic ester (e.g. methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, isobutyl acrylate, 2-ethoxyethyl acrylate, glycidyl acrylate, tetrahydrofurfuryl acrylate, acrylic 2-hydroxyethyl acid, 2-hydroxypropyl acrylate, 1,4
-butanediol diacrylate, 1,6-hexanediol acrylate, pentaerythritol triacrylate, etc.), methacrylic acid and methacrylic acid esters (such as methyl methacrylate, ethyl methacrylate, butyl methacrylate,
Isobutyl methacrylate, t-butyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, isodecyl methacrylate, lauryl methacrylate, lauryl-tridecyl methacrylate, tridecyl methacrylate, cetyl-stearyl methacrylate, stearyl methacrylate, methacrylic acid Cyclohexyl, benzyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl methacrylate, etc.) At least one selected from these groups is used. Particularly preferred are functional ones having at least one of a hydroxyl group, a carboxyl group, a glycidyl group, and an amino group. In addition to such monomers, acrylamide, acrylonitrile, acrolein, vinyl acetate, styrene, N-methylolacrylamide, vinylpyridine, maleic anhydride, vinylpyrrolidone, butadiene, etc. can also be used in combination. The above-mentioned graft rubber that can be used as a component in the present invention is produced by grafting a graft monomer to urethane rubber in a conventional manner. For example, after dissolving the urethane rubber in an organic solvent, a radical-generating polymerization initiator (benzoyl peroxide, azobisisobutyronitrile, kyumene hydroperoxide, t-butyl hydroperoxide, potassium persulfate, ammonium persulfate) salt, etc.) and the graft monomer, and heat under reflux at 60 to 100°C for over 1 hour.
Preferably, the graft polymerization is carried out for 2 to 4 hours. In such a graft, the ratio of urethane rubber and graft monomer is 100 parts of urethane rubber (parts by weight,
It is desirable to use 10 to 70 parts of the graft monomer (the same applies hereinafter), and to graft at least 10 to 30 parts of the graft monomer. The monomer to be grafted is
If it is less than 10 parts, the adhesion will not be improved by grafting, and if it exceeds 30 parts, the solution viscosity may increase or gelation may occur during polymerization. The above polymerization initiator is usually 0.3 to 100 parts of urethane rubber.
It is used in an amount of 1.0 part, but if it is too small, excessive polymerization rate and polymerization time will be required, while if it is too large, the polymerization will be good, but the viscosity of the solution will increase and gelation may occur. The graft rubber thus obtained is used in a 5-30% solution of the organic solvent. Examples of the rosin resin or rosin resin derivative that is a component in the present invention include pentaerythritol ester of rosin resin, glycerol ester, hydrogenated rosin resin, methyl ester of hydrogenated rosin resin, triethylene glycol ester, and pentaerythritol. - Examples include esters, rosin esters, polymerized rosin resins, glycerol esters of polymerized rosin resins, and hydrogenated rosin resins and derivatives of hydrogenated rosin resins are particularly preferred. The amount used is usually based on the ingredients
The amount may be selected in the range of 3 to 20 parts, preferably 5 to 10 parts per 100 parts. The chlorinated rubber, which is a component in the present invention, refers to natural rubber or synthetic rubber that is reacted with chlorine. ”,
"CR-10", "CR-20", "CR-40", "CR-40"
"CR-90" and "CR-150" are commercially available, as well as synthetic rubber products such as chlorinated polyethylene and chlorinated polypropylene, which are made by chlorinating polyethylene and polypropylene, and chlorinated polypropylene made from polyvinyl chloride and chlorinated polyethylene. Examples include vinyl chloride. These chlorinated rubbers are aromatic rubbers,
It dissolves well in ester-based and ketone-based organic solvents. The amount of chlorinated rubber to be used may be selected within the range of 0.5 to 20 parts per 100 parts of the normal ingredients. Organic solvents that are components in the present invention include, for example, ester-based solvents (ethyl acetate, butyl acetate, etc.), ketone-based solvents (methyl ethyl ketone, cyclohexanone, acetone, etc.), aromatic solvents (toluene, xylene, benzene, etc.), and chlorine-based solvents (triclene, etc.). , methylene chloride, etc.). In the present invention, the component crosslinking agent is an isocyanate compound that is used as a crosslinking agent for ordinary chloroprene solvent-based adhesives and urethane rubber adhesives, and has a high vapor pressure, low toxicity to the human body, and is easy to handle. For example, triphenylmethane triisocyanate (Bayer
Desmodur R, 20% methylene chloride solution),
Triisocyanate phenyl thiophosphate (Desmodur RF manufactured by Bayer, 20% methylene chloride solution), isocyanate compound obtained by adding trimethylolpropane to tolylene diisocyanate (Coronate L manufactured by Nippon Polyurethane Co., Ltd., 75% ethyl acetate solution) ), special grade MDI (Millionate MR manufactured by Nippon Polyurethane Co., Ltd.), etc. In such isocyanate compounds, the active hydrogen group of the hydroxyl group in the molecular chain of the component reacts with the isocyanate group, resulting in crosslinking, so it contributes to improving adhesive strength.
The number may be selected to be 3 to 50 copies per 100 copies. The polyurethane adhesive according to the present invention is usually put to practical use in the form of a two-component organic solution consisting of an adhesive main component consisting of the above-mentioned components, and a crosslinking agent as a component. In addition, if necessary, an appropriate amount of polyoxyalkylene ether polyol having two or more ether groups in the molecule may be added to the main adhesive component to increase compatibility with the plasticizer of the flexible vinyl chloride sheet and further improve adhesive strength. It's okay. Such polyoxyalkylene ether polyols are low molecular weight active hydrogen compounds having two or more active hydrogen atoms (e.g. ethylene glycol, propylene glycol, butylene glycol, 1,6
- One or more types of diols such as hexanediol, triols such as glycerin, trimethylolpropane, and 1,2,6-hexanetriol, and amines such as ammonia, methylamine, ethylamine, propylamine, butylamine) A random or block copolymer polyoxyethylene-propylene polyol obtained by ring-opening polymerization of propylene oxide and ethylene oxide in the presence of polyoxytetramethylene glycol obtained by ring-opening polymerization of tetrahydrofuran, 2 in 1 molecule
It has ~3 hydroxy groups. The adhesive of the present invention having the above structure is applied to one of the adhesive surfaces of the adherend (single-sided application).
After the open time, the adhesion can be maintained by simply overlapping the adhesive surfaces of other adherends and lightly pressing them together. Can be omitted. Further, as an application of the present invention, at least one of the adherends
In addition to adhesion of polyvinyl chloride sheets, films, or foams containing a large amount of plasticizer to plastic materials, wood, or metal materials, polyurethane adhesives are mainly used for bonding plastic films, etc. It is also useful as an adhesive for lamination processing. Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples. Examples 1 to 5 For Examples 1 to 2, non-grafted urethane rubber (“Pandex” manufactured by Dainippon Ink Industries, Ltd.) was used.
T5205'') and organic solvent (MEK: methyl ethyl ketone), or for Examples 3 to 5, non-grafted urethane rubber (``Pandex T5205'')
and graft monomers (MMA: methyl methacrylate, EA: ethyl acrylate, 2-HEMA: 2-hydroxyethyl methacrylate, AN: acrylonitrile), an organic solvent (MEK), and a polymerization initiator (BPO: benzoyl peroxide). Chlorinated rubber and rosin resin ("Foural A" manufactured by Hercules, "Ester" manufactured by Arakawa Chemical Co., Ltd. Gum A"
``Superester A100'' manufactured by the same company or ``Harie Star 80P'' manufactured by Harima Kasei Kogyo Co., Ltd.) is added and dissolved to create the main adhesive component (the number of parts of each component is listed in Table 1). A polyurethane resin adhesive is prepared by blending 20 parts of a crosslinking agent (Desmodur R) with 100 parts of the main component. Comparative Example 1 A polyurethane resin adhesive is prepared in the same manner as in Example 1 except that chlorinated rubber and rosin resin are not added. Comparative Examples 2 to 3 In Example 1, coumaron resin (“Esclone G-” manufactured by Shintetsu Kagaku Co., Ltd.) was used instead of rosin resin.
A polyurethane resin adhesive is prepared in the same manner except that a phenol resin ("Tamanol 373" manufactured by Arakawa Chemical Industries, Ltd.) is used. Comparative Examples 4-5 A polyurethane resin adhesive is prepared in the same manner as in Example 5 except that coumaron resin or phenol resin is used in place of the rosin resin as in Comparative Examples 2-3. Test example: PVC sheet leather product (Orsia manufactured by Sunstar Giken Co., Ltd.) and ABS resin (Kane Ace manufactured by Kanekabuchi Kagaku Co., Ltd.) made into strips of 20 mm wide x 100 mm long as adherends. Each adhesive of Examples 1 to 5 or Comparative Examples 1 to 5 is applied to a resin plate at about 100 g/m ₂ , and after drying with a solvent, the resin plates are bonded together to prepare an adhesive test piece. After curing and curing this test piece for one day, the 180° peel adhesion strength was determined by autograph.
Measure the peel adhesion strength after aging for 3 weeks in a heated atmosphere of 110℃, and then perform a 24-hour creep test with a load of 100g on one end of the sheet side in a heated atmosphere of 110℃ to measure the peel length. . The test results are shown in Table 1.

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Claims (1)

[Scope of Claims] 1. Thermoplastic polyester urethane rubber and/or the thermoplastic polyester urethane rubber grafted with at least one member selected from the group of acrylic acid, acrylic ester, methacrylic acid and methacrylic ester, rosin resin and/or a rosin resin derivative, a chlorinated rubber, an organic solvent, and an isocyanate compound as a crosslinking agent.