JPS62121735A - Improvement of coatability and adhesion of hard coat surface - Google Patents

Abstract

PURPOSE:To improve the coatability or adhesion of the surface of a synthetic resin article subjected to hard coat treatment with a silicon hard coating agent, by roughening the surface of the article and plasma-treating it in the presence of a plasma-nonpolymerizable reaction gas. CONSTITUTION:The surface resistance, etc., of a synthetic resin article such as a polycarbonate article are improved by improving surface strength, etc., by hard coat treatment with a silicon hard coating agent. The surface of the synthetic resin article subjected to hard coat treatment is roughened by sand blasting, rubbing with sand paper or the like operation. The resulting surface is plasma-treated in the presence of a plasma-nonpolymerizable reaction gas (e.g., N2 or Ar) to improve the coatability and adhesion of the hard coat. In this way, it is possible to choose a paint or an adhesive among a variety of them.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for improving the adhesion of a bottom resin product that has been hard coated using a silicone thread hard coat agent.

[Background of prior art and invention]

Conventionally, transparent materials such as polycarbonate or polymethyl methacrylate (E947!) were used instead of glass for the purpose of weight reduction or impact resistance. Gohiro resin is used.

′! Next, in automobiles and the like, polycarbonate or polymethyl methacrylic products have recently been frequently used as decorative parts that take advantage of transparency and have an unprecedented appearance.

By the way, since these resin products do not have sufficient surface strength against abrasion and are easily scratched, they are hard coated with a hard coat agent VC to prevent scratches.
The hard-coated surface has strong water repellency and is chemically stable, so ordinary paints do not adhere to it, and it also has poor contact with N.

Therefore, even if there is a demand for painting the periphery of hard-coated synthetic resin glass with F-black stripes or attaching tape using adhesive, it is difficult to meet these demands. Melt.

On the other hand, if you use a special primer or a special paint or adhesive, it can be done, but the number of steps will increase and the material cost will be high. ! The special primer used has problems with its quality and stability, making it impractical.

Hard coating agents currently in practical use are broadly classified into the following three types.

(11(a) Melamine thread hard coat agent + silicone hard coat agent, e.g. MR-52 (Jojin Kasei) (b) Melamine thread hard coat agent, e.g. MR67 (
(2) Silicone-based (organopolysiloxane-based) hard coating agent, such as MR-114 (Jōjin Kasei) Table 1 shows the state of paint adhesion when painting was applied to the treated hard coat surface.

Table-1 The test product (A) is polycarbonate (Panrai) 7
1 j: Konjinka ash) was hard-coated with the hard-coating agent of (11(a)),
Hard-coated with the hard-coating agent of l), (
C) is a polycarbonate (Panlite 71.4: treated with the hard coating agent of Jyojin Kasei J mentioned above; ) treated with a hard coating agent.

From the results shown in Table 1, it is clear that the coating properties of the paint on the hard coated surface are poor, and from this it can be seen that the N contact properties of the adhesive are also poor.

In other words, in test products (a) and (b), which form a paint film and cure when paint is applied to the hard coat surface, the adhesion of the hard coat surface is weak and the paint film peels off easily, making it impractical. It has no V'i and cannot be used.

On the other hand, the test product treated with a silicone-based hard coating agent slightly repelled the paint, exposing the hard coat surface in some places, and even after the paint was cured, the layering properties of the paint were extremely poor.

In the case of test specimens treated with a UV-curing acrylic hard coating agent, the paint was largely repelled and 60 to 70% of the hard coat surface was exposed, but the adhesion of the paint was determined after the paint was cured. is excellent, unlike the previous champions.

The present inventor attempted to apply plasma treatment to improve the paintability and adhesion of bonded resin split products hard-coated with these hard-coating agents, and found that test products treated with melamine thread hard-coating agents (a) and (b) are 0
We applied plasma treatment in the presence of a reactive gas containing 2, under conditions that are more severe than those used for ordinary polypropylene treatments, and the test specimens treated with a UV-curable acrylate hard coating agent had a zero snow resistance. It has been found that by performing plasma treatment in the presence of a gas that does not have plasma polymerizability, such as a gas containing Plasma treatment alone is not sufficient for test sample picks treated with a chemical agent.
Neither paintability nor adhesion was improved.

[Purpose of the invention]

An object of the present invention is to provide a method for improving the paintability and adhesion of synthetic resin front and back products hard coated with a silicone hard coat agent.

[Structure of the invention]

The present invention is characterized by roughening the surface of an aS product that has been hard-coated with a silicone-based hard-coating agent, and then plasma-treated in the presence of a reactive gas that does not have plasma polymerizability. This is a method for improving the paintability or adhesion of personal items.

Plasma treatment alone did not improve the paintability or adhesion of synthetic resin cracked products that had been hard-coated with a silicone-based hard-coat agent, but by roughening the hard-coat surface and then plasma treatment, V A friend who discovered a scale that significantly improves the cold-manufacturability and adhesion properties of the product and came up with the present invention.

In the present invention, any method may be used to roughen the hard coat surface, such as sandblasting, friction with sandpaper, friction with steel cool, etc. Plasma treatment may be performed with 0. Preferably, it is carried out in the presence of a reaction gas containing N2. The process may be carried out in the presence of any gas that does not have plasma polymerizability and is commonly used in plasma processing, such as Ar or He gas.

Further, as the plasma treatment device, any device may be used, such as a device conventionally used to improve the paintability, N contact property, etc. of synthetic resins such as polypropylene and polyethylene.

Example 1 The polycarbonate base material surface indicated by A, B, O, and D shown in Table 1 below was hard coated using a silicone hard coat agent, and the test product was then plasma treated under the following conditions. , R-26, a paint manufactured by Nippon B Chemical Co., Ltd.
5 to a thickness of about 50 μm, baked and hardened at 90°C for 40 minutes, and left at room temperature for 72 hours.
A test for the adhesion of the L-liquid paint was carried out by pasting a 5-vm wide knit cellophane tape, peeling off the tape vigorously, and determining the number of coats of fe 1 w angle remaining on the hard coat surface. For comparison, polypropylene tree J] 1BO-8D
(Mitsubishi Yuka) (ratio 1), Engineering F-15OA (Mitsubishi Yuka) (
Similar tests were also conducted on R2) and 5p-766X (Idemitsu Petrochemical (RioS)).

The results are shown in Table-1.

Used 9 plasma processing equipment manufactured by BRANS○N Engineering PC Co., Ltd. 3005-1120 8T
QAAUTOMAT CPLASMA SYI3TE
M plasma processing conditions High frequency: 1 & 56 MH2 reaction gas:
○ Goose or N1 Reactive gas pressure crab 1. OTorr High Frequency Output Crab 200W In the case of polypropylene, sanding is required 1.
The beer peel strength in the 80' direction was reduced to about 1/2.

From the results shown in Table 1, it can be seen that the paintability and adhesion of synthetic resin hard coated with a silicone hard coat agent are significantly improved by roughening the surface before plasma treatment.

In addition, when performing partial VC'I11 coating, masking is applied before sanding and removed after painting, which reduces the number of steps.

〔Effect of the invention〕

It is possible to significantly improve the paintability or adhesion of synthetic resin products that have been hard-coated with silicone-based hard-coating agents, which was difficult to do in the past.Therefore, the choice of paints and adhesives can be freely chosen. .

Claims (1)

[Claims] 1. A hard coat surface characterized by roughening the surface of a synthetic resin product that has been hard coated using a silicone hard coat agent and then subjecting it to plasma treatment in the presence of a reactive gas that does not have plasma polymerizability. A method for improving the paintability or adhesion of.