JPH0426628B2 - - Google Patents

Description

[Detailed description of the invention]

Industrial Application Field The present invention is a poly(vinyl chloride/vinyl carbamate) compound that contains vinyl chloride units in its molecule and has excellent adhesion to polyvinyl chloride base materials as well as excellent heat resistance. The present invention relates to a release agent consisting of the following, and a method for producing the same. Prior Art and Problems For tapes that are stored in the form of rolls and are rewound when used, such as adhesive tapes that have an adhesive material on a base material, it is difficult to peel them off from the back side. To facilitate, the back side of the substrate is treated with a release agent. The performance required for the releasable treated layer to be formed is that it can be laminated and that the tape etc. can be smoothly rewound during use, that is, a balance between the adhesion and releasability of the adhesive to the releasable treated layer. In addition to general properties such as being able to remove adhesives, not contaminating the adhesive surface and reducing adhesive strength, and having excellent adhesion to the base material and not falling off easily,
It is also important that the material has excellent heat resistance and that its peeling properties do not change over time due to heat. Conventionally, as a stripping agent using an isocyanate compound, one was known in which polyvinyl alcohol was dispersed in an insoluble solvent, and an isocyanate compound was added thereto and reacted (Tokuko Sho et al.
29-7333). However, the release agent has poor adhesion or adhesion to the base material, especially a base made of polyvinyl chloride, and easily falls off from the base material due to friction or heat history, and its release properties deteriorate due to heat history. There were problems such as poor heat resistance, such as an increase in the force required for unwinding. Means for Solving the Problems The present inventors have overcome the above problems, and have achieved a balance between adhesion or adhesion to a base material made of polyvinyl chloride, adhesion to an adhesive surface, and removability.
As a result of extensive research in order to develop a release material with excellent heat resistance, the inventors discovered that the objective could be achieved using a poly(vinyl chloride/vinyl carbamate) compound, leading to the present invention. That is, the present invention provides the formula () The vinyl chloride unit represented by and the formula () (However, R is a hydrocarbon group having 8 or more carbon atoms or a halogen-substituted hydrocarbon group.) It has a vinyl carbamate unit represented by in the molecule, and the content of the vinyl chloride unit is 5 to 90 moles. %
And poly(vinyl chloride/vinyl carbamate)
A stripping agent consisting of a vinyl chloride/organic acid vinyl copolymer and a general formula: RNCO (where R is a hydrocarbon group having 8 or more carbon atoms or a halogen-substituted hydrocarbon group). An isocyanate compound represented by
Provided is a method for producing a stripping agent made of a poly(vinyl chloride/vinyl carbamate) compound, characterized in that the hydroxyl group in the saponified product is reacted with 0.1 equivalent or more of the isocyanate compound. . Function: Based on the vinyl chloride unit in the molecule, it can have excellent adhesion or adhesion to polyvinyl chloride base materials. Moreover, the release characteristics can be controlled by adjusting the content ratio of vinyl chloride units and vinyl carbamate units. Furthermore, it is possible to improve the adhesion or adhesion to a substrate by leaving a hydroxyl group in the molecule and modifying the hydroxyl group with a modifier such as polyvalent isocyanate or polyvalent acid chloride. Examples of Constituent Elements of the Invention The release agent of the present invention is a poly(vinyl chloride) having vinyl chloride units and vinyl carbamate units represented by the following formulas () and (), respectively, in the molecule.
It consists of vinyl carbamate) type compounds. (However, R is a hydrocarbon group having 8 or more carbon atoms or a halogen-substituted hydrocarbon group.) The above poly(vinyl chloride/vinyl carbamate) compound can be produced, for example, by the following method. That is, a vinyl chloride/vinyl organic acid copolymer is saponified to convert all or part of its organic acid vinyl units into vinyl alcohol units. Next, the prepared saponified vinyl chloride/organic acid vinyl copolymer is dissolved in a soluble solvent, and a predetermined amount of an isocyanate compound is added to the resulting solution and the mixture is reacted with heating. I can do it. At that time, in order to promote the reaction between the hydroxyl group and the isocyanate group, a catalyst typified by an organic tin compound or the like may be used, if necessary. The end point of the reaction depends on the amount of the isocyanate compound used, but is usually determined by the disappearance of the isocyanate group from the reaction system. In the above reaction, a copolymer of a saponifiable organic acid vinyl ester and vinyl chloride is used as the vinyl chloride/organic acid vinyl copolymer.
Generally, vinyl chloride/vinyl acetate copolymers, vinyl chloride/vinyl propionate copolymers, and the like are used because of their ease of availability. In addition, in the present invention, the copolymer also contains copolymerizable monomers other than vinyl chloride and organic acid vinyl ester, such as acrylic acid, methacrylic acid, 2-hydroxyethyl acrylate, and 2-hydroxyethyl methacrylate. It's okay. In the present invention, the content of vinyl chloride units is 5
~90 mol% vinyl chloride/vinyl organic acid copolymer is used. If the content of vinyl chloride units is less than 5 mol %, the resulting release agent will have poor adhesion or adhesion to the polyvinyl chloride base material, and if it exceeds 90 mol %, the introduction of hydroxyl groups will be insufficient due to saponification, resulting in isocyanate As a result of insufficient introduction of hydrocarbon groups based on the system compound, the resulting stripping agent has poor stripping performance. The average degree of polymerization of the vinyl chloride/vinyl organic acid copolymer is suitably from 100 to 5,000, particularly from 200 to 3,000, based on vinyl units. If the average degree of polymerization is less than 100, the resulting release agent will have poor film strength and heat resistance;
If it exceeds 5000, it is unfavorable in terms of reaction work such as solubility. The vinyl chloride/vinyl organic acid copolymer can be saponified by a conventional method. That is,
A vinyl chloride/organic acid vinyl copolymer is dissolved in alcohol, an alcohol/aromatic mixed solvent, or other soluble solvent, and then heated in the presence of a catalyst consisting of an alcoholate, an alkali, or an acid for saponification treatment. This can be done by At that time, the alcohol is methanol,
Generally, ethanol, isopropanol, etc. are used, benzene, toluene, xylene, etc. are used as aromatic solvents, and ketones etc. are used as other solvents. Saponification is preferably carried out so that the content of vinyl alcohol units is 10 mol% or more, particularly 15 mol% or more. Solvents used to make a solution of the obtained saponified vinyl chloride/organic acid vinyl copolymer are not limited, but include dimethyl sulfoxide, N-methylpyrrolidone, triethyl phosphate, diethylene glycol dimethyl ether, and acetylacetone. , sulfolane, butyl lactone,
Water-soluble materials such as dioxane, tetrahydrofuran, and methyl lactate are preferably used. The solvent is used in an amount that can dissolve the entire amount of the saponified product, and generally 3 to 30% of the saponified product is used.
8 weight times is used. In the present invention, a poly(vinyl chloride/vinyl carbamate) compound is obtained by adding an isocyanate compound to a saponified solution of a vinyl chloride/organic acid vinyl copolymer and causing a reaction.
The isocyanate compound has the general formula:
RNCO (wherein R is a hydrocarbon group having 8 or more carbon atoms or a halogen-substituted hydrocarbon group) is used. Examples of R include linear or branched alkyl groups, alkenyl groups, alkadinyl groups, aucopolyenyl groups, alkynyl groups, or halogenated products thereof, each having 8 or more carbon atoms, particularly 8 to 32 carbon atoms. Therefore, typical examples of isocyanate compounds include octyl isocyanate, nonyl isocyanate, decyl isocyanate, undecyl isocyanate, dodecyl isocyanate, tridecyl isocyanate, tetradecyl isocyanate, pentadecyl isocyanate, hexadecyl isocyanate, heptadeyl isocyanate, octadecyl isocyanate, Nonadecyl isocyanate, eicosyl isocyanate, heneicosyl isocyanate,
docosyl isocyanate, tricosyl isocyanate, tetracosyl isocyanate, pentacosyl isocyanate, hexacosyl isocyanate, octacosyl isocyanate, nonacosyl isocyanate, triacontylsocyanate,
Hentriacontyl isocyanate, dotriacontyl isocyanate, 4-methyl-10-ethyl-2-dodecenyl isocyanate, octadecenyl isocyanate, decynyl isocyanate, polychlorohexadecyl isocyanate, perfluorohexadecinyl isocyanate, etc. can be given. The amount of the isocyanate compound to be used is preferably 0.1 equivalent or more, particularly 0.1 to 1.1 equivalent, based on the hydroxyl group in the saponified vinyl chloride/organic acid vinyl copolymer. If the amount used is less than 0.1 equivalent, the introduction of hydrocarbon groups etc. will be insufficient and the resulting release agent will have poor release performance. As described above, a poly(vinyl chloride/vinyl carbamate) compound containing 5 to 90 mol % of vinyl chloride units in the molecule and having vinyl carbamate units is obtained. The stripping agent of the present invention is composed of the poly(vinyl chloride/vinyl carbamate) compound, and the stripping agent obtained above is usually purified and dissolved in an appropriate solvent for practical use. The release agent of the present invention preferably contains vinyl carbamate units in an amount of 10 mol% or more, particularly 20 mol% or more. Further, the organic acid vinyl unit in which the poly(vinyl chloride/vinyl carbamate) type compound remains is desirably 50 mol% or less. Furthermore, a hydroxyl group may remain in the molecule. Allowing hydroxyl groups to remain is the same as controlling the content ratio of vinyl chloride units, vinyl carbamate units, and organic acid vinyl units.In addition, it is necessary to control the content ratio of vinyl chloride units, vinyl carbamate units, and organic acid vinyl units. In addition to being effective in adjusting the adhesion or adhesion to the substrate and the peeling characteristics, it is also possible to introduce a modifier via the remaining hydroxyl groups. Effects of the Invention The release agent of the present invention is based on a poly(vinyl chloride/vinyl carbamate) compound and contains vinyl chloride units in the molecule, so it has particularly excellent adhesion or adhesion to polyvinyl chloride bases. .
Moreover, the peeling performance can be controlled by controlling the content ratio of vinyl chloride units and vinyl carbamate units. In addition, it is also possible to leave a hydroxyl group, and by introducing a polyvalent isocyanate or the like through the hydroxyl group, it is possible to modify the adhesion to the substrate. Moreover, it has the advantage that the modification process can be carried out efficiently and easily. Reference Examples 1 100 parts (parts by weight, the same shall apply hereinafter) of a vinyl chloride/vinyl acetate copolymer with an average degree of polymerization of 1200 and a content of vinyl chloride units of 50 mol% was mixed with 300 parts of methyl isobutyl ketone and 100 parts of methanol. The mixture was uniformly dissolved in a mixed solvent (60°C), 10 parts of a 2N sulfuric acid/methanol solution was added thereto, and the product was saponified at 60°C for 6 hours. The product was thoroughly washed with methanol and then dried. The obtained product is one in which vinyl acetate units are saponified to vinyl alcohol units,
Its saponification degree was 99 mol%. This was confirmed by analysis using an infrared absorption spectrometer based on the presence or absence of spectral absorption at 1720 cm ^-1 based on the ester moiety of vinyl acetate and spectral absorption at 3700 cm ^-1 based on the hydroxyl group. Reference Example 2 A saponified product was obtained according to Reference Example 1 using a vinyl chloride/vinyl acetate copolymer with an average degree of polymerization of 1250 and a vinyl chloride unit content of 30 mol%. The degree of saponification was 99 mol%. Reference Example 3 According to Reference Example 2, a saponified vinyl chloride/vinyl acetate polymer having a saponification degree of 50 mol% was obtained. Reference Example 4 A saponified product was obtained according to Reference Example 1, except that a vinyl chloride/vinyl acetate copolymer having an average degree of polymerization of 1200 and a vinyl chloride unit content of 70 mol % was used. The degree of saponification was 99 mol%. Example 1 20 parts of the saponified vinyl chloride/vinyl acetate copolymer obtained in Reference Example 1 was placed in a 500 c.c. four-necked flask equipped with a reflux condenser and a water metering receiver.
130 parts of dimethyl sulfoxide was added and dissolved, and this solution was heated at 140° C. for 2 hours to remove water in the saponified product and the solvent. Thereafter, the system was cooled to 100°C, 50 parts of octadecyl isocyanate was added, and the mixture was reacted at 120°C for about 5 hours. No residual isocyanate groups were observed in the reaction station obtained. The product was then precipitated in methanol to obtain the target poly(vinyl chloride/vinyl carbamate) compound. Example 2 Using the saponified product obtained in Reference Example 2, the target poly(vinyl chloride) was prepared according to Example 1, except that the amount of dimethyl sulfoxide used was 230 parts, and the amount of octadecyl isocyanate was 80 parts. A vinyl carbamate) type compound was obtained. Example 3 A target poly(vinyl chloride/vinyl carbamate) compound was obtained according to Example 2, except that 40 parts of the saponified product obtained in Reference Example 3 and 280 parts of dimethyl sulfoxide were used. . Example 4 A target poly(vinyl chloride/vinyl carbamate) compound was obtained in the same manner as in Example 1, except that the saponified product obtained in Reference Example 4 was used and the amount of octadecyl isocyanate was changed to 35 parts. Comparative Example 1 20 parts of polyvinyl alcohol with a degree of saponification of 88 mol% and an average degree of polymerization of 1000 was dispersed in 204 parts of xylene,
116 parts of octadecyl isocyanate was added to this and reacted, and the product was purified to obtain a stripping agent. Evaluation test Purified products of poly(vinyl chloride/vinyl carbamate) compounds obtained in Examples 1 to 4 or Comparative Example 1
The stripping agent obtained in step 1 is made into a 1% by weight toluene solution, and this solution is applied to a 100μ thick film made of soft polyvinyl chloride.
The coating amount (solid content) is 0.05g/m ² on a film of m
A release treated film was obtained by coating and drying, and the film was examined for release force (180 degree peel value, tensile speed 300 mm/min). The measurement is
Apply vinyl chloride adhesive tape (No.
21R, manufactured by Nitto Electric Industry Co., Ltd.) with a rubber roller weighing 2 kg, and then heated to 20°C, 50°C, 60°C or 70°C.
After heating for 24 hours at 20°C, the samples were left at 20°C for 4 hours. The results are shown in the table. Note that Comparative Example 2 is the value for a soft polyvinyl chloride film that was not treated with a release agent.

[Table] Note that the releasable treated layer according to the example did not fall off from the base even when rubbed with a finger, and did not cause contamination when brought into contact with a stainless steel plate, but the layer according to comparative example 1 fell off easily and Contaminated the stainless steel plate.

Claims (1)

[Claims] 1 Formula () The vinyl chloride unit represented by and the formula () (However, R is a hydrocarbon group having 8 or more carbon atoms or a halogen-substituted hydrocarbon group.) It has a vinyl carbamate unit represented by in the molecule, and the content of the vinyl chloride unit is 5 to 90 moles. %
poly(vinyl chloride/vinyl carbamate)
A stripping agent consisting of a chemical compound. 2 The average degree of polymerization of the poly(vinyl chloride/vinyl carbamate) compound is 100 or more based on vinyl units.
5000, the release agent according to claim 1. 3. The stripping agent according to claim 1, wherein the content of organic acid vinyl units in the poly(vinyl chloride/vinyl carbamate) compound is 50 mol% or less. 4 Saponified product of vinyl chloride/organic acid vinyl copolymer and general formula: RNCO (where R is carbon number 8
These are the above hydrocarbon groups or halogen-substituted hydrocarbon groups. ) and an isocyanate compound represented by
A method for producing a release agent made of a poly(vinyl chloride/vinicarbamate) compound, which comprises reacting the hydroxyl group in the saponified product with 0.1 equivalent or more of the isocyanate compound.