JPH0582814B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a thermoplastic resin film with improved adhesion, and an object thereof is to provide a thermoplastic resin film that has good adhesion to both hydrophilic and hydrophobic polymers. It is in. (Prior Art) As is well known, thermoplastic resin films such as polyester, polyamide, polypropylene, etc., especially polyester films, especially polyethylene terephthalate films, have excellent mechanical strength, heat resistance, chemical resistance, transparency, dimensional stability, etc. Because of this, base films for magnetic tapes, insulating tapes,
It is used in a variety of applications such as photographic film, tracing film, and food packaging film. However, since polyester films generally have low adhesive properties, when laminating magnetic materials, photosensitive agents, matting agents, etc., it is common to subject the film surface to corona discharge treatment and further provide an anchor coating agent. Furthermore, when used for food packaging, the adhesiveness with the printed layer and heat sheet layer is weak, resulting in a disadvantage that the overall heat-sealing strength is also reduced. Corona discharge treatment is generally used as a method to improve the adhesion of thermoplastic resin film surfaces.In addition, physical treatments such as ultraviolet irradiation treatment, plasma discharge treatment, flame treatment, and corona discharge treatment under a nitrogen atmosphere are also used. Treatment methods, chemical treatment methods such as alkali treatment and primer treatment, and treatment methods using these in combination are known. however,
There are no thermoplastic films, especially polyester films, that have good adhesion to both hydrophilic and hydrophobic polymers. (Problems to be Solved by the Invention) In view of the above circumstances, the present inventors developed a thermoplastic resin film in which polyethylene glycol grafted with one or more vinyl monomers is laminated on at least one side of a thermoplastic resin film. It has been found that resin films, particularly polyester films, have good adhesion to both hydrophilic and hydrophobic polymers. (Means for Solving the Problems) That is, the present invention is an easily adhesive film formed by laminating polyethylene glycol grafted with at least one vinyl monomer on at least one side of a thermoplastic resin film. A preferred embodiment (1) of the present invention is an easily adhesive film having a vinyl monomer grafting ratio of 5 to 300%. In a more preferred embodiment (2) of the present invention, in any of the above inventions or embodiments (1), at least one vinyl monomer is added to at least one side of the melt-extruded unstretched or uniaxially stretched thermoplastic resin film. After laminating polyethylene glycol grafted with the above, it is an easily adhesive film that is further stretched at least uniaxially. The molecular weight of the polyethylene glycol in the vinyl monomer grafted polyethylene glycol used in this invention is preferably 1,000 to 10,000. More preferably 5000 to 75000, particularly preferably 10000
~50000. If the molecular weight is less than 1,000, the adhesion to thermoplastic resin films, especially polyester films, is low, and if it is more than 100,000, it is difficult to produce grafted products because of the small amount of graft reaction. Further, the vinyl monomer used here is not particularly limited, but those listed in the following formula []-[] are preferred.

【table】 \

_R17

【table】 ‖

OH

Compounds represented by the formulas [] to [] include:
An ester consisting of acrylic acid or methacrylic acid and an alcohol having a lower alkyl group such as methyl, ethyl, propyl, butyl, amyl, hexyl, heptyl, octyl, 2-ethylhexyl, or styrene and methyl, ethyl, propyl, Butyl, amyl, hexyl, heptyl,
o, m, p- consisting of lower alkyl such as octyl
Monoalkylstyrene, 2,4-(or 2,5-,
2,6-,3,4-,3,5-)dialkylstyrene, 2,4,5-(or 2,4,6-)trialkylstyrene, 2,3,4,5-tetraalkylstyrene or these Examples include α-methyl substituted products of . Furthermore, acrylic acid, methacrylic acid and their hydroxyalkyl esters, dialkyl esters,
Alkoxy alkyl esters, alkyl alkylene glycol esters, glycidyl esters, and o-(or m-, p-) monochlorostyrene,
2,3-(or 2,4-,2,5-,2,6-,
3,4-,3,5-)dichlorostyrene 2,3,
4-(or 2,4,5-)trichlorostyrene,
Furthermore, styrene such as tetrachlor (or pentachlor), 2-chloro-5-methyl, 4-chloro-
halogen-substituted styrene derivatives such as chloro-alkylstyrenes such as 3-methyl and p-chloromethyl;
o-(or m-, p-)hydroxystyrene, o
- (or m-, p-) hydroxy or alkoxystyrene derivatives such as methoxystyrene, ethoxystyrene, 3-methoxy-4-hydroxystyrene, ethylene sulfonic acid and its sodium,
Alkali metal salts such as potassium or vinyl alkyl sulfones such as vinyl methyl sulfone, vinyl ethyl sulfone, vinyl butyl sulfone, vinyl sulfonamides such as vinyl sulfonamide, vinyl sulfone anilide, vinyl sulfone methyl anilide, styrene sulfonic acid and its sodium, Alkali metal salts such as potassium and mono(2
-methacryloyloxyethyl) acid phosphate, mono(2-methacryloyloxyethyl) acid phosphate, among which acrylic acid, methacrylic acid, glycidyl acrylate, glycidyl methacrylate, mono(2-methacryloyloxyethyl) acid phosphate, Ethyl) acid phosphate, mono(2-acrylolololokiethyl) acid phosphate, hydroxyethyl acrylate, and hydroxyethyl methacrylate are effective. The grafting rate of these vinyl monomers is 5~
300% is preferred. More preferably 10-200%, most preferably 15-150%. If the grafting rate is less than 5%, it will be difficult to adhere to hydrophobic polymers.
If it exceeds 300%, the adhesion to hydrophilic polymers decreases. These grafted products can be manufactured according to conventional methods. That is, a water-soluble polymerization initiator such as ceric ammonium nitrate, ceric ammonium sulfate, potassium persulfate, ammonium persulfate, or hydrogen peroxide is present, and the reaction is carried out in an aqueous medium. The concentration of polyethylene glycol in the reaction system is preferably 5 to 50%. The graft polymerization reaction is usually carried out under cooling or heating.
℃, preferably 5 to 80℃ is recommended. This is because below 0°C, the polymerization rate is slow, and above 100°C, the polymerization initiator will be decomposed and the stability of the polymerization system will be reduced, resulting in gels and the like. The amount of graft polyethylene glycol applied to the thermoplastic resin film is 0.01~
It is 5g/ ^m2 . If it is less than 0.01 g/m ² , the adhesiveness will be poor, and if it is more than 5 g/m ² , the film will have poor slipperiness and blocking resistance. Note that the coating liquid is prepared by diluting the graft polyethylene glycol in a solvent such as water. When applying the grafted polyethylene glycol, colorants, antistatic agents, crosslinking agents, anti-blocking agents, lubricants such as inorganic or organic particles, other polymers, ultraviolet absorbers, anti-deterioration agents, and other substances may be used according to the present invention. It may be added to an extent that does not impair the effect of. In the present invention, polyethylene glycol grafted with a vinyl monomer is applied to a thermoplastic resin film by a coating method, and the thermoplastic resin film may be either an unstretched film obtained by melt extrusion or a biaxially oriented film, but biaxially oriented When coating on film, it is difficult to apply it uniformly because the film is wide and the film travels at high speed, and the former two are more preferable in terms of adhesion and durability of the coating agent. . Furthermore, the adhesion can be further improved by performing corona discharge treatment in air or nitrogen atmosphere, ultraviolet irradiation treatment, etc. before and after lamination. Further, in the present invention, it is preferable to use a polyester film, particularly a polyethylene terephthalate film, as the thermoplastic resin film, since the film layer generated during the lamination and film forming processes can be recovered and reused. Coating thermoplastic resin films, especially polyester films, produced by the above method can be used as base films for magnetic tapes, base films for label stickers, base films for chemical mats, films for overhead projectors, films for food packaging, Used for film for other purposes. (Example) Examples of the present invention will be described below. In the middle part of the example, percentages are based on weight. Note that the grafting rate is expressed by the following formula. Grafting rate (%) =
Grafted monomer amount (gr)/backbone polymer amount (g
r) × 100 Example 1 (1) Production of polyethylene terephthalate Lead hydroxide pbO in 200 ml of ethylene glycol
Dissolve 2.2g of pb(OH) ₂ (pb0.95×10 ^-2 mol),
2.0 g (1.9×10 ⁻² mol) of GeO ₂ was added to this solution and heated under reflux at the boiling point of ethylene glycol at 197° C., and a transparent solution was obtained in about 30 minutes. Next, polyethylene terephthalate was produced using this solution as a polycondensation catalyst. 620 parts of dimethyl terephthalate, 480 parts of ethylene glycol, and 0.036 parts of zinc acetate Zm (OAc) 2.2H _{2 O} as a transesterification catalyst were placed in a transesterification reactor, and the transesterification reaction was carried out by gradually raising the temperature from 150°C to 230°C. I walked around,
It took 120 minutes to complete the distillation of methanol. Next, the contents were transferred to a polycondensation apparatus, 2.7 parts of the above catalyst solution was added as a polycondensation catalyst, the temperature was gradually raised and the pressure was reduced, and the temperature was raised to 280°C over 1 hour to carry out the polycondensation reaction under a high vacuum of 0.5 mmHg. The polymer obtained after 25 minutes had an intrinsic viscosity of 0.63 and a melting point of 262°C. (2) Production of grafted polyethylene glycol 100g of polyethylene glycol with a molecular weight of 20,000
20 g of acrylic acid was added to a polyethylene glycol solution dissolved in 860 c.c. of water, and N ₂ gas was passed through the solution for 30 minutes. On the other hand, ceric ammonium nitrate
A solution dissolved in 1N nitric acid aqueous solution (20c.c.) was added to the above polyethylene glycol aqueous solution with stirring while keeping it at 60℃, and _N2 gas was passed through it for 120 minutes to obtain acrylic acid-grafted polyethylene glycol (grafting rate). 20%). Monomers for grafting [] Acrylic acid [] Glycidyl methacrylate [] Mono(2-acryloxyel) acid phosphate (3) Production of inline coated film Polyethylene terephthalate produced in (1)
The unstretched film was melt-extruded at 280 to 300°C, cooled with a cooling roll at 15°C, and then stretched to a thickness of 1000 microns. , the above coating solution was applied using an air knife method, dried with hot air at 70°C, then stretched 3.5 times in the transverse direction at 98°C with a tenter, and further heat-set at 200 to 210°C to form a biaxial sheet with a thickness of 100 microns. A stretched coated polyester film was obtained. Examples 2 to 3 A polyester film was obtained in the same manner as in Example 1 except that the vinyl monomer was changed. Examples 4 to 5 A polyester film was obtained in the same manner as in Example 1 except that the amount of polyethylene glycol or vinyl monomer added was changed. Comparative Example 1 A polyester film was obtained in the same manner as in Example 1 except that no coating was applied in Example 1. Comparative Example 2 A polyester film was obtained in the same manner as in Example 1 except that non-grafted polyethylene glycol was used in Example 1. Comparative Examples 3 to 6 Polyester films were obtained in the same manner as in Example 1, except that in Example 1, the grafting monomer concentration and polyethylene glycol concentration outside the claimed range were used.

[Table] PVA and PVC were colored with a red dye that was dissolved at 10% in water and DMF (dimethylformamide) and dissolved in each solvent. These were printed at a coating weight of 2 g/m ² and a tape peel test was conducted. In the tape peeling test, cellophane tape (product name: L-Pack, manufactured by Nichiban Co., Ltd.) is applied uniformly to the ink-printed surface, then quickly peeled off in 180-degree and 360-degree directions, and the amount of ink remaining on the film is measured. Judging visually, the area where ink remains is 95% of the total area.
% or more ◎, 50-95% ○, 10-50% △, 10%
The following are indicated with an x. From Table 1, it can be seen that the Examples show good adhesion to both PVA and PVC, but the Comparative Examples have no or insufficient adhesion. (Effects of the Invention) As described above, the film obtained by the method of the present invention has the effect of having good adhesion to both the hydrophilic polymer and the hydrophobic polymer.

Claims (1)

[Claims] 1. On at least one side of the thermoplastic resin film,
An easily adhesive film characterized by being laminated with polyethylene glycol grafted with at least one vinyl monomer. 2. The easily adhesive film according to claim 1, wherein the vinyl monomer grafting ratio is 5 to 300%. 3. A film obtained by laminating polyethylene glycol grafted with at least one vinyl monomer on at least one side of a melt-extruded unstretched or uniaxially stretched thermoplastic resin film, which is then further stretched at least uniaxially. The easily adhesive film according to any one of Items 1 and 2.