JPS63172778A - Coating agent having excellent rigidity and anti-fogging effect - Google Patents

Abstract

PURPOSE:To provide a coating agent which is useful for lenses of eyeglasses, protective glass for a liquid crystal display part, glass for vehicles, etc. and has excellent rigidity and anti-fogging effect, consisting of an acrylic graft polymer, a specified photopolymerizable prepolymer, a crosslinking agent and a photopolymerization initiator. CONSTITUTION:A carboxyl group-terminated prepolymer obtd. by radical- polymerizing, e.g., methyl methacrylate in the presence of a chain transfer agent such as thioglycol is reacted with glycidyl methacrylate. The resulting macromer is radical-polymerized with a comonomer to obtain a ladder graft polymer such as an acrylic graft polymer (A). 100pts.wt. component A is blended with 2-20pts.wt. photopolymerizable polymer (B) composed of at least one polyacrylate selected from the group consisting of polyurethane acrylate, epoxy acrylate and polyester acrylate, 0.02-5pts.wt. crosslinking agent (C) selected from the group consisting of (meth)acrylic acid and p-toluenesulfonic acid and 2-10pts.wt. photopolymerization initiator (D).

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a coating agent with excellent hardness and antifogging effects. The coating agent of the present invention can be widely used for brass base materials and the like.

In particular, it can be used for general sunglasses, ski goggles, eyeglass lenses, underwater glasses, windshields of motorcycle helmets, protective glass for liquid crystal displays, vehicle glass, etc.

(Prior Art) Conventionally, the following anti-fog treatment techniques are known.

(1) A method of applying a surfactant to the surface of the base material.

(2) Add a blush active agent to the base material Method.

(3) A method of applying paint or coating agent to the surface of the base material to form a film.

(4) A method of modifying the surface of a base material by physical means.

(Problems to be Solved by the Invention) However, the above prior art has the following problems. That is, (1) the method of applying a surfactant to the surface of a base material is described, for example, in JP-A-54-88937 and JP-A-5
No. 5-102631. Although this method is effective with simple treatment, it is washed away by water, rainwater, etc., and there is a problem with sustainability.

(2) A method of blending a surfactant into a base material, for example, JP-A-53-89247, JP-A-54-550
No. 44, JP-A-54-55048, JP-A-54-88
No. 545 and Japanese Unexamined Patent Publication No. 56-22341. According to this method, the active ingredients are extracted by sunlight (ultraviolet rays) and microorganisms, resulting in a decrease in concentration and reduced effectiveness.

(3) A method of applying a paint or coating agent to the surface of a base material to form a film, for example, a method of heat treating a mixture of 2-hydroxylethyl methacrylate and polyethylene methacrylate (Japanese Patent Publication No. 52-47754)
, a method of graft polymerizing a reactive silicon compound onto a hydrophilic resin and heating the mixture with a nonionic organosilicone surfactant (Japanese Patent Publication No. 53-18347); A method by coating a water-soluble resin reacted with isocyanate (Japanese Patent Publication No. 53-183411), a photocurable ethylenically unsaturated compound containing a parent wood group and a photocurable ethylenically unsaturated compound not containing a parent wood group. A method of applying a coating solution containing a photoinitiator and curing it by irradiating it with UV light using a UV curing device (
JP-A No. 53-28587), a method of coating a hydrophilic resin with a composition prepared by adding a surfactant to a metal salt of acrylic acid or methacrylate and heat-treating it (JP-A No. 61-22)
8031) etc. However, even with these methods, the coating after coating has problems in anti-fogging properties, hardness, abrasion resistance, adhesion, water resistance/moisture resistance, transparency, durability, etc.

(4) A method of modifying the surface of a base material by physical means, such as a method of corona discharge treatment or a method of plasma discharge treatment (JP-A-53-56177, JP-A-56-
No. 1130, JP-A-56-Ii1434, JP-A-57
-1540, Special Publication No. 57-1541), etc. But according to these means a special outfit! is required, which increases the cost and limits the applicable plastic base materials. In particular, using these methods to improve antifogging properties improves surface wettability and water absorption, making condensation less likely, but on the other hand, surface hardness, abrasion resistance, and adhesion decrease, making it impossible to obtain a well-balanced surface. was the current situation.

(Means to Solve the Problems) Therefore, in order to solve the drawbacks of the conventional anti-fog treatment technology described above, the present inventors developed an acrylic graft-type polymer (
Hereinafter referred to as Macromer or Macrosentsuma...)
As a result of many years of research and development, focusing on the anti-fog properties of photopolymerizable polymers and the high hardness of photopolymerizable polymers, we have applied a method of compounding these resins and curing them by irradiating them with UV light using a UV curing device. This method instantly cures the film, expanding the range of plastic substrates that can be applied to it, and by changing the blending ratio of macromer and photopolymerizable polymer, it can be applied to plastic substrates. This technology has led to the establishment and invention of a technology with excellent fogging properties and coating properties, in which polyurethane acrylate is added as a photopolymerizable prepolymer to 100 parts by weight of a macromer selected from at least one kind of macromer or macromer. , 2 to 20 parts by weight of a polyacrylate selected from at least one of epoxy polyacrylate and polyester acrylate, and a crosslinking agent selected from at least one of acrylic acid, methacrylic acid, and P-toluenesulfonic acid, and 100 parts by weight of the macromer. 0.02 to 5 parts by weight per 100 parts by weight of photoinitiator, and 2 to 10 parts by weight of photoinitiator per 100 parts by weight of photopolymerizable prepolymer. It is something to do.

(Example) The present invention will be explained in detail below.

The method for synthesizing the comb-shaped graft polymer by the macroscopic method used in the present invention is, for example, to radically polymerize methyl methacrylate using thioglycolic acid as a chain transfer agent to obtain a terminal carboxylic acid type prepolymer, and then add glycidyl When methacrylate is reacted, it becomes a macromer of polymethyl methacrylate with methacryloyl groups.

Next, a suitable comonomer (B,
When C) is subjected to radical copolymerization, a comb-shaped graft polymer having A as a branch component and B (or C) as a trunk component is obtained. Unlike conventional graft polymerization methods, this macroscopic polymerization method synthesizes the branch portions in advance, making it possible to design molecules according to the purpose, and allowing the combination of branch components and trunk components to be freely selected. In the present invention, 10,031 parts of one or more commercially available macromers are selected, and acrylic acid, methacrylic acid, and P-1-luenesulfonic acid play a role as a crosslinking agent as described above. Therefore, 0.02 to 5 parts per 100 parts of macromer!
A concentration that occupies i parts is preferred. If it exceeds 51 parts by weight, hardness and abrasion resistance will improve, but antifogging properties and adhesion will decrease, and if it is less than 0.02 parts by weight, antifogging properties will improve, but water resistance/humidity and durability will decrease. Therefore, each is not desirable.

The photoinitiator is 2 to 1 part by weight per 100 parts by weight of the photopolymerized polymer.
Concentrations accounting for 0 parts by weight are preferred. If it exceeds 10 parts by weight, it is undesirable because it lowers weather resistance or discolors the coating, and if it is less than 2 parts by weight, the UV curing speed is undesirable.

As the macromer used in the present invention, acrylic macromers such as those illustrated below are commercially available.

However, MM^ Methyl methacrylate HEM^ 2
-Hydroxyethyl methacrylate N-MAM N-methylacrylamide.

In addition, CP C (Corn Product Cor
Macr.

ier@registered trademark). It is also commercially available from Toagosei Kagaku Kogyo ■.

The photopolymerizable prepolymers used in the present invention are commercially available as shown below.

(1) As for polyurethane acrylate, the product name is
Manufacturer name (2), product name for epoxy polyacrylate
Manufacturer name Product name Manufacturer Master Craftsman uses acrylic acid, methacrylic acid, p
-Toluenesulfonic acid and the like were used, and these chemicals were manufactured by Tokyo Kasei Kogyo ■.

Next, as a photoinitiator, Merck product Daroc
ur's 1173 (registered trademark), C4ba-Ge
igy product 1rgacure” 184.651
(registered trademark) etc.

The plastic substrate to which the present invention is applied is a resin with good transparency and excellent optical properties.

For example, polycarbonate, methyl methacrylate, diethylene glycol bisallyl carbonate (CR-3
9), transparent vinyl chloride, polystyrene, polyester,
Examples include cellulose resins such as cellulose acetate butyrate, cellulose propionate, and cellulose acetate. Molded products made of the above resins include films,
Examples include sheets, lenses, etc.

The selection of the organic solvent used in the present invention takes into consideration the following: (1) It should not dissolve, swell, whiten, crack, etc. the plastic base material, and (2) It should be a good solvent for the resin used in the present invention. Must.

Specific organic solvents include methyl alcohol, ethyl alcohol, n-butyl alcohol, isobutyl alcohol, isopropyl alcohol, ethyl acetate, cyclohexanone, toluene, xylene, methyl cellosolve, ethyl cellosolve, butyl cellosolve, acetic acid cellosolve acetate, and the like.

Further, as a method for coating the brass base material and molded articles, a dipping method, a spray method, a flow coater method, a spin coater method, etc. can be used depending on the object to be coated.

The thickness of the coating is suitably 1 to 15 .mu.m in order to maintain various properties, but the thickness of 3 to 8 .mu.m is desirable in consideration of aesthetics.

Next, embodiments will be described.

The coating agent of this example was prepared by blending macromer (A), polyacrylate (B), crosslinking agent (C), photoinitiator (D), and organic solvent (F) in the proportions shown in Table 1. did. These coating agents are applied by a dipping method, and after drying, a UV curing device with an output of 80 W/as (I-Graphic, K) is used.

A film having a thickness as shown in υV heat irradiation Table 2 was formed using a υV heat irradiation film (Model No. 1-L212), and the following performance tests were conducted and evaluated. The results are also shown in Table 2.

Adhesion test: A cut that reaches the underlying plastic substrate is cross-cutted into 100 squares by making 11 parallel lines vertically and horizontally at 2 mm intervals on the coating surface using a knife, and then attaching cellophane adhesive tape. was peeled off and the remaining number was counted and expressed with the denominator as 100.

Water resistance test: After placing the test piece in a constant temperature bath adjusted to a temperature of 40±0.5℃ for 24 hours, take out the test piece and check with the naked eye whether there are any abnormalities such as peeling of the coating, whitening, cracks, etc. observed.

Pencil scratch test: Pencil hardness was measured according to J Summer S, Ni-5400.

Anti-fog test: A transparent test box with a capacity of lj2 is divided into two parts on the left and right by a partition wall. A part of the partition wall is cut open, a rubber seal is held to hold the test piece, and a metering pump is applied to the back side of the anti-fog coating at 500 c/min.
Cooling water at a temperature of 5° C. is fed at a flow rate of c and the cold water is circulated so as to come into contact with the test piece. On the other hand, air containing steam is sent to the anti-fog coating surface at a flow rate of 500 cc per minute from a steam generator heated to a temperature of 40 ± 0.5°C using an air metering pump, and this temperature difference is used to prevent fogging. The time required for the coating surface to become cloudy and for water droplets to adhere was measured.

Table-1 Table-20 jI'I Polymethyl Cellulose Cellulose Cellulose (material)
Pentene Acetate Propionate Acetate Butyrate 1kll (lvm (gm) 3-5
3-5 3-5 5-7
3-5 dry conditions 'C+30 8fl
40 50
fiO min 1 2
0 40 30
20UvyIQt curing conditions (shooting distance flit (cm) 10
30 50 50
S.

Irradiation time (cedar) 3 2
Ko 33 Spirit n Brush Yume Moki Shiritsu: (H) 3 ~ 42 ~ 332 ~ 32 ~ 3 + 27 Fu (Experience +00 / 100 +00 /
100 1+107100 100 / +0
0 1 fl [l / 10100 l aqueous test
No abnormality No abnormality No abnormality
No abnormality No abnormality 1111I humidity test
No abnormality No abnormality No abnormality
No abnormality No abnormality Prevention 11 seconds Time for fogging or water droplet adhesion (seconds + 220 200
210 220 150 (Note)
, polyester (PET), polymethylpentene (TP)
X), cellulose acetate (CA).

Abbreviated as cellulose propionate (CP) and cellulose acetate butyrate (CAB), respectively.

Table 2 ■ Item Polystyrene Clear chloride Diethylene Polycar Methyl meta base material Vinyl Glycol Bonate Acrylic bisallyl φ Thickness of carbonate film (lm) 4-6 6-6
3-5 5-7 4-7 Dry smoke conditions:'
C6011080IIs 70, min.
20 20 20 3
40UV irradiation curing conditions/irradiation distance (cs) 30
20 20 10
20 irradiation time (seconds) 2
2 2 3
3 Pencil scratch test: (H) 3~4 3~
4 3~5 3~5 3~5vE,a
Exam +00/100 10!1/1
oll 100/1110 100/100
100/100 liquor test No abnormality No abnormality No abnormality No abnormality
Humidity resistance test with no abnormality No abnormality No abnormality No abnormality No abnormality No abnormality Anti-fog test with fogging or water droplet adhesion time (seconds) 170 180
180 225 180 (note)
, polystyrene (Psi, transparent vinyl chloride (PVC),
diethylene glycol bisallyl carbonate,
(CR-39), polycarbonate (PC), and methyl methaxolate (MMA).

(Effects of the Invention) As is clear from the above, the coating agent with excellent hardness and antifogging effect according to the present invention can be said to have solved the drawbacks by utilizing the features of the photopolymerizable polymer and the ultraviolet irradiation device. That is, although it has the characteristics of high hardness and wear resistance, its use as a coating agent has been limited due to its drawbacks of shrinkage and poor adhesion.

Therefore, the inventors of the invention established a technology that allows coating of a functional film on various transparent plastic substrates by blending macromers. By using the agent,
It has the effect of being widely applicable to protective glass for liquid crystal displays, various lenses, various eyeglasses, glass for vehicles, anti-fogging properties for buildings, and other uses.

Procedural amendment February 17, 1988

Claims (1)

[Scope of Claims] A photopolymerizable prepolymer selected from polyurethane acrylate, epoxy polyacrylate, and polyester acrylate based on 100 parts by weight of the acrylic graft polymer selected from at least one type of acrylic graft polymer. 2 to 20 parts by weight of at least one selected polyacrylate and at least one crosslinking agent selected from acrylic acid, methacrylic acid, p-toluenesulfonic acid, based on 100 parts by weight of the acrylic graft polymer. .02 to 5 parts by weight and the photoinitiator is a photopolymerizable prepolymer 100%
A coating agent with excellent hardness and antifogging effect, consisting of 2 to 10 parts by weight.