JPS58118852A - Cast film - Google Patents

Abstract

PURPOSE:To provide the titled film which is non-yellowing and has excellent durability, by casting a soln. contg. a polyurethane resin contg. a polycarbonate diol as a polyol component, an acrylic copolymer, an aminoplast and a catalyst on a substrate and heating it. CONSTITUTION:A polyurethane resin obtd. by adding, if necessary, a low-molecular diol such as 1,6-hexanediol to a polycarbonate diol, adding an aliph. diisocyanate thereto to produce a prepolymer and extending its chain with hydrazine, an acrylic copolymer, an amino-plast obtd. by methylol-etherifying melamine having a triazine skeleton, and a crosslinking catalyst such as hypophosphorous acid are mixed together. The resulting soln. is cast on a releasable substrate and heated to effect crosslinking, thus obtaining the desired cast film.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a highly durable, non-yellowing polyflexone-based casting film. A crosslinkable acrylic copolymer having a hydroxyl group, an amide group, etc. is added to t to provide a polyflexion group casting film having excellent durability and crosslinked by aminoblasting.

Conventionally, synthetic 11[il films have been used as labeling materials. However, it is necessary for the material to have appropriate flexibility and elongation in terms of processability and adhesion suitability.

Plasticized polyvinyl chloride is generally used as such a coating material, and polyurethane is also used in some cases.

However, for applications that are used outdoors or under harsh conditions, such as for automobiles, retroreflectors, and signboards, the current quality coating materials described above are not satisfactory, and further improvements in quality are required. There is.

That is, a coating film used for this type of use is required to have excellent transparency, be free from contamination with foreign matter, fish eyes, etc., and have no directionality. □Most of the coatings for labeling materials as described above are manufactured by the casting method.

After this film is subjected to various processing, it is finally applied to a label, a sticker, or a protective film to a substrate for use.

The substrate to be pasted can be flat or smooth, or curved, and the film is required to adhere completely to the curved surface.

Therefore, the skin 11 used as the KFi labeling material must have appropriate flexibility, elongation and strength, and be excellent in adhesion suitability.

In addition, various physical properties are required for the application.

Among these, especially for automobiles, there is no discoloration due to exhaust gas heat, ultraviolet rays, etc., resistance to gasoline, brake oil, machine oil, waxing, terry liquid, etc., light rays due to outdoor exposure, hydrolysis, It is shown by high resistance to deterioration due to oxidation etc. and scratch resistance.
There is a strong demand for so-called durability.

However, at present, there is no coating for labeling materials that satisfies such a wide range of demands, and there is a strong demand for the appearance of such a coating.

Conventionally, widely used plasticized polyvinyl chloride resin casting films have drawbacks such as deterioration due to long-term outdoor exposure, resistance to some chemicals, and low frictional strength and lack of scratch resistance.

-1 Rethane resin coating gFi It is possible to obtain coatings with various properties depending on their composition, but long-term outdoor Ik
In the case of discoloration due to dew and deterioration due to hydrolysis, etc., the defects can be expected to be approximately as follows: 0 In other words, products that use aromatic incyanate as the incyanate component cause severe yellowing due to exposure, etc., and cannot be used as a coating for labeling materials. is inappropriate.

Furthermore, aliphatic isocyanates are less likely to yellow, but are susceptible to hydrolysis.

Next, regarding the polyol component, polyvarnish/chillediol has poor hydrolyzability, although it depends on the type. Diamines such as polytetramethylene ether glycol are effective as chain extenders to increase the softening temperature of the Fi resin, and hydrazines are effective in improving resistance to oxidation.

The inventors of the tree completed this invention as a result of extensive research based on this knowledge.

Conventional urethane elastomers are used for durable fishing purposes.
Although Vi does not exhibit sufficient properties, it has been found that by crosslinking the rethane etW&K of the present invention, its properties are greatly improved and the physical properties required for automobiles etc. can be obtained. .

The present inventors have found that by crosslinking even in conventional polyester- and polyether-type polyol-based Fretan machines wI, the physical properties of the film are significantly improved, and it has excellent properties as a labeling material. It has been found that

Even when a urethane resin with a polycarbonate diol as a base is used as a non-crosslinked elastomer as a polyol component, the film is superior as a film for labeling materials compared to conventional polyvinyl chloride or phrethane films. I also found However, even with this elastomer, it has been difficult to satisfy the properties required for durable use.

As a result of further research, the inventors found that by crosslinking this elastomer, it became clear that a labeling material that was fully satisfactory for durable use could be obtained, thus completing the present invention.

The polyflexane tree used in this development is made by adding a low molecular weight diol to a polycarbonate diol (for example, Desmohen, manufactured by Bayer AG), using an aliphatic diisocyanate, and adding a solvent. It is provided by forming a prepolymer in the presence or absence of the compound and then chain-extending it in a solvent using diamine, hydrazine, etc.

As the acrylic copolymer, the above-mentioned polyurethane etW&
It is a copolymer that has compatibility with aminoplasts and has groups in the copolymer that can be crosslinked with aminoplasts, such as hydroxyl groups and amide groups.

Aminoplast is a methylol ether compound having a triazine skeleton or a partial condensate thereof. cross-linking ts
Fi is a commonly used organic or inorganic acid group.

Skin 1IFi of this invention, the above polyurethane resin solution,
The acrylic copolymer solution, aminoplast, crosslinking catalyst, and if necessary pigments, solvents, and other additives are added, stirred uniformly, filtered, and then defoamed.

The solution thus obtained is applied onto release paper or polyester film using, for example, a doctor knife coater.

Next, most of the solvent is evaporated by pre-drying, and then thermal crosslinking is performed.

The film thus obtained can be used as it is, or it can be printed on the surface of the kishichi, coated with a protective coating, cut into appropriate sizes, or wrapped with release paper, liner, etc., and rolled into products. .

Examples will be shown below to specifically explain the present invention.

All parts are by weight.

Example 1 Polycarbonate diol (manufactured by Bayer AG, Desmohen 2020 E, average molecular weight 2000) 700 parts, 1.6
- Charge 17.7 fl of hexanediol and 222 s of inphorone diisocyanate into a reactor,
The mixture was stirred at 5° C. for 4 hours to obtain a prepolymer.

This was diluted to 70% using toluene and cooled.

(1) A certain amount of the prepolymer obtained above with a concentration of 70 m was weighed into a reactor.

Dimethylformamide (DMF) was added to this to dilute it to over 80%. Then, while stirring at room temperature, a separately weighed equimolar amount of inphorone diamine in a DMF solution was added little by little to elongate the solution, and after the viscosity reached 860 voids at 80°C, dibutylamine was added until the isocyanate group disappeared. added.

(2) Operate in the same manner as (1) using hydrazine hydrate,
An elastomer solution was obtained.

(3) A certain amount of the prepolymer solution was weighed out, and 50 mol% of hydrazine hydrate was added to the remaining incyanato groups of 100 mol%, followed by stirring at room temperature for 80 minutes.

Next, a separately weighed 50 mol % solution of inphorondiamine in 8051 DMF was added little by little, and after the viscosity reached 860 voids at 80° C., dibutylamine was added until the incyanato groups disappeared.

Comparative example Polyhexylene adipate diol (average molecular weight 200
A prepolymer solution was obtained in the same manner as in Example 1 except that 0) was used.

(1) Using the L prepolymer and isophorone diamine in the same manner as in Example 1 (1), an elastomer solution was obtained.

(2) An elastomer solution was obtained in the same manner as in Example 1 (2) using hydrazine and water.

(3) Using hydrazinohydrate and isophorone diamine, the same procedure as in Example 1 (3) was carried out to obtain an elastomer solution.

Example: Put 240s of toluene and 960 parts of isoprono into a polymerization vessel, heat with stirring, and maintain at reflux temperature to produce 279 parts of methyl methacrylate, 18 m of hydroxyethyl methacrylate, 1 m of dimethylaminoethyl methacrylate.
．． 66m and azobisisobutyronitrile (AIBN
) 0.768 was weighed out, added to the polymerization vessel, and refluxed for sO minutes.

3 parts were added. After 2 hours had elapsed, 1.84 g of benzyl chloride was added thereto, and after refluxing for an additional hour, toluene tos and 290 parts of Impropatol were added and the mixture was cooled.

Example 8 (1) 280 parts of the 80% urethane elastomer solution obtained in Example 1 and Comparative Example, 80 parts of the acrylic copolymer solution obtained in Example 2, and aminoplast (Sumi Tex MC, Custom Chemical @) 1511 and 10%
1.6 ml of hypophosphorous acid solution was mixed, stirred well, filtered, and left to stand.

(2) The 80% urethane elastomer solutions obtained in Example 1 and Comparative Examples were diluted to 25% with ethylene glycol monoethyl ether, stirred well, filtered, and allowed to stand.

Example 4゜The solutions obtained in Example 8 (1) and (2) were coated on release paper with a doctor knife caulk to a dry film thickness of 60 μm.
Apply it so that it becomes like this, pre-dry it at 80℃ for 8 minutes,
Next, heating or thermal crosslinking was performed at 145° C. for 10 minutes.

The skin 11 thus obtained was subjected to various tests such as thermal discoloration and chemical resistance, and the results shown in Table 1 were obtained.

For comparison, similar tests were also conducted on commercially available polyvinyl chloride films for two-belling materials and non-yellowing type polyurethane films.

O: No change observed at all.

○: Almost no change observed.

Δ: Slight change observed.

X: Large change.

XX=Very large change.

0, OFi means that there is no problem in practical use, Δ#'i means that problem may occur in practical use, and ×, XX means that it cannot be used in practical use.

(Note) This indicates that the Fi film deteriorates and becomes fluid, making it impossible to judge.

The results shown in Table 1 above demonstrate that the casting film for labeling materials of the present invention has all properties significantly improved compared to conventional labeling material films, and can be used for durable purposes.

Claims (1)

[Claims] (1) 6% polyflex resin containing polycarbonate diol as the polyol component <2) Acrylic copolymer, (3
A casting film characterized in that a solution containing a) aminoblast and (4) a crosslinking catalyst is applied onto a releasable base material and crosslinked by heating.