JPH0333280A - Method for dyeing acrylic resin molded article - Google Patents

Abstract

PURPOSE:To form a colored layer having excellent endurance on an acrylic resin molded article by applying a mixture containing a silicon compound having methacryloxy group and hydrolysate of a silicon compound at a specific ratio to the acrylic resin molded article and curing the mixture and then bringing the applied molded article into contact with a treating liquid consisting of coloring agent-containing silicon dioxide. CONSTITUTION:A mixed liquid containing a silicon compound having methacryloxy group expressed by formula I (R<1> is organic group having methacryloxy group; R<2> is one or plural kind of binding groups selected from alkoxy, alkoxyalkoxy, acetoxy and chloride) and hydrolysate of silicon compound expressed by formula II (R<2> is mentioned above) so that a ratio of R<1>SiO3/2 weight (A) of the silicon compound expressed by formula I to SiO2 weight (B) of the silicon compound expressed by formula II may be 0.1<B/A <0.5 is applied to an acrylic resin molded article and cured and the applied molded article is brought into contact with a treating liquid containing dye, pigment, etc., in a silicofluoric acid solution kept in supersaturated state to form colored and coated layer having good adhesion and excellent endurance on the molded article.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for coloring acrylic resin molded bodies, and particularly relates to a method for coloring acrylic resin molded bodies, particularly flat, film-shaped, rod-shaped, tubular, spherical, fibrous, woven,
The present invention also relates to a method for forming a colored layer with excellent chemical and mechanical durability on the surface of an acrylic resin molded body having a shape such as a processed molded body.

[Conventional technology]

For a long time, the method of coloring acrylic resin molded bodies has been to add a coloring agent during the process of synthesizing the molded body. For example, in the case of resin moldings, it is common to mix and knead colorants such as inorganic pigments, organic pigments, or dyes into resin raw materials, and then uniformly disperse the colorant in the resin before polymerizing and curing it to form it. Met. However, the method of mixing colorants into acrylic resin moldings is difficult due to the heat resistance of the colorant to the resin processing temperature.
In addition to limitations such as the effect on resin polymerization, curing, and crosslinking conditions, there are also limitations to the use of colorants, such as weather resistance to air and water, and the inability to locally color molded objects.

For this reason, in addition to methods of mixing colorants into acrylic resin moldings, so-called printing or dyeing methods have been widely used to form colored layers on the surfaces of acrylic resin moldings. The printing method involves adsorbing colored ink made of inorganic or organic pigments or dyes onto the surface of an organic molded object, and is characterized by the fact that it is possible to locally color the molded object, and it can be colored in a wide variety of colors. However, in this method, on a smooth surface such as a resin molded body, the adsorption power of the coloring agent in the ink to the surface of the molded body is weak, and peeling of the ink film often occurs. Furthermore, since the surface of the resin molded product does not absorb the ink vehicle, it is necessary to accelerate the evaporation of the solvent by heating, etc. However, since high temperature heating is not possible, the solvent may remain on the printed surface, causing odor and blocking. (sticking of printed matter) occurs to 0.

On the other hand, dyeing is mainly used to color fibrous molded bodies,
Colorants, mainly dyes, are adsorbed onto the fiber surface. In this case, the coloring process is extremely complicated, as it is necessary to carefully select the type of dye, auxiliary agent, coexisting ions, etc., depending on the type of fiber, in order to increase the binding strength between the dye and the fiber.

Furthermore, as is common to all of these printing and coloring methods, since the colorant is directly exposed to the outside air, it is susceptible to oxidation and hydrolysis due to oxygen and moisture in the air.・Due to elution from organic solvents and various chemicals, mechanical wear damage, etc., the degree of coloring often decreases and discolors over time.

[Problem to be solved by the invention]

In view of the drawbacks of such printing and dyeing methods, the present invention aims to provide an improved coloring and dyeing method for forming a colored layer with excellent chemical and mechanical durability on the surface of an acrylic resin molded article. .

In other words, by incorporating the coloring agent into the silicon dioxide film, it is possible to eliminate the situation where the colorant comes into direct contact with the outside air as seen in printing and dyeing methods, and the protective effect of the silicon dioxide film prevents the colorant from coming into contact with water and organic solvents. The purpose is to suppress the reaction of , thereby increasing the weather resistance of the colored layer. Furthermore, due to the abrasion resistance of silicon dioxide, mechanical abrasion durability can also be improved.

On the other hand, by interposing an organic silicon compound (coupling agent) between the colorant-containing silicon dioxide and the acrylic resin molding, the bond between the colored layer and the acrylic resin molding becomes stronger. In this way, in the present invention, an organosilicon compound (coupling agent) is formed in the form of a film on the surface of an acrylic resin molded body,
After that, by forming a colorant-containing silicon dioxide film,
The purpose is to form a colored layer with excellent adhesion and chemical and mechanical stability on the surface of an acrylic resin molded article.

[Means and effects for solving the problems] The present invention is to color an acrylic resin molded body using the method for producing a silicon dioxide-coated acrylic resin molded body proposed in JP-A-1-101339.

That is, after coating an acrylic resin molded body with an organosilicon compound and curing it to form a primary coating, dyes and pigments are added to the acrylic resin molded body with the primary coating and a supersaturated hydrosilicofluoric acid solution of silicon dioxide. This is a method for producing a silicon dioxide-coated acrylic resin molded article, in which a silicon dioxide film containing an organic colorant is formed on a first film by contacting a treatment liquid containing an organic blue agent such as the above.

The primary coating is a silicon compound having a methacryloxy group represented by the following general formula (I) and a hydrolyzate of the silicon compound represented by the general formula (n), and a methacryloxy group represented by the general formula (I). R' S l of a silicon compound having a group
o The ratio of the weight in terms of 3/□ (A) and the weight in terms of SiO2 (B) of the silicon compound represented by the general formula (II) is 0.1
The gist of the present invention is a method for producing an organic colorant-containing silicon dioxide-coated acrylic resin molded article, which is formed by coating and curing a mixture containing <B/A<0.5.

R'5i(R2)3 (I)Si(
R3) 4 −・−・−・・・・・・・・・・ (
(2) (In the formula, Rl is an organic group having a methacryloxy group, and R2 and Rl are one or more bonding groups selected from an alkoxy group, an alkoxyalkoxy group, an acetoxy group, and a chlorine element.) Directly by precipitation method When coating the surface of a plastic molded object with a silicon dioxide film containing an organic colorant, the adhesion is weak and only an uneven film can be obtained due to the poor reactivity and wettability of the hydrosilicofluoric acid solution and the plastic. However, if the plastic molded body is coated with an organosilicon compound and cured in advance, the silanol groups on the surface will serve as a bonding site with the silicon component in the hydrosilicofluoric acid solution. It is possible to improve the adhesion and unevenness of the containing silicon dioxide film.

However, the first method obtained by coating and curing an organosilicon compound
When the thickness of the subsequent coating is reduced to several hundred angstroms or less, the deposition method is used to create an even and uniform film.
In order to obtain an organic colorant-containing silicon dioxide coating with strong adhesion, it is necessary to select an organic silicon compound depending on the type of plastic.

As a result of intensive research into organosilicon compounds suitable for forming a primary film on acrylic resin molded bodies, the present inventors found that a silicon compound having a methacryloxy group represented by the above general formula (I) It has been found that a mixed system of a specific ratio of a hydrolyzate of a silicon compound represented by the general formula (II) is optimal.

The present invention will be explained in detail below.

In the present invention, among the silicon compounds used to form the primary film, the silicon compound having a methacryloxy group represented by the general formula (I) is preferably γ-methacryloxy group-ropyltrimethoxysilane. Also, the general formula (
Examples of the silicon compound represented by II) include tetraethoxysilane, and its hydrolyzate is a silicon compound in which part or all of the alkoxy group, alkoxyalkoxy group, acyloxy group, or chlorine element is substituted with a hydroxyl group. It also includes those in which substituted hydroxyl groups are partially naturally condensed. These hydrolysates can be easily obtained, for example, by hydrolysis in a mixed solvent such as water and alcohol in the presence of an acid.

As the silicon compound having a methacryloxy group represented by the general formula (I), 1@ may be used alone or two or more types may be used in combination. Similarly, the silicon compounds represented by the general formula (II) may be used alone or in combination of two or more.

In the present invention, the mixing ratio of the silicon compound having a methacryloxy group represented by general formula (I) and the hydrolyzate of the silicon compound represented by general formula (n) is such that the silicon compound having a methacryloxy group represented by general formula (1) is R'Si of the silicon compound having
The ratio of the O372 equivalent weight (A) and the SiO2 equivalent weight (B) of the silicon compound represented by the general formula (H) is 0.1<B
/A<0.5.

The adhesion of the organic colorant-containing silicon dioxide coating obtained by the precipitation method is largely controlled by the average molecular weight of the acrylic resin of the acrylic resin molding forming the coating and the mixing ratio B/A of the silicon compound.

In the present invention, in order to obtain an organic colorant-containing silicon dioxide film with strong adhesion, the average molecular weight of the acrylic resin substrate used is preferably 80,000 or less, and the B/A ratio is 0.1<B/ It needs to be A.

As a method for coating and curing such a mixture of silicon compounds on an acrylic resin molded body to form a primary film, a dip coating method using a coating solution prepared by dissolving the mixture of silicon compounds in various solvents is suitable. .

The primary coating to be formed can be applied to a glass substrate (for example, ordinary plate glass,
When a film is formed under similar conditions on (soda lime glass, etc.), the film can be formed under conditions such that a film with a thickness of 5 to 50 nm, preferably 10 to 30 nm, is created. desirable.

In other words, if the primary coating is created under conditions that allow a coating up to a thickness of about 50 nm to be formed on a glass substrate, it will be possible to form a coating that sufficiently follows even submicron surface irregularities. can get. 50 when created on a glass substrate
If the primary film is created under conditions where it becomes thicker than 10 nm, shape followability may deteriorate. Further, conditions where the film thickness becomes thinner than 5 nm on a glass substrate are not suitable because this results in a decrease in the adhesion strength of the organic colorant-containing silicon dioxide film obtained by the precipitation method.

In the present invention, in order to form a primary film having such a thickness, it is preferable that the silicon compound concentration in the coating liquid is 0.5 to 3% by weight.

In this way, the first
Since the silicon compound having a methacryloxy group represented by the general formula (I) penetrates into the interior of the acrylic resin substrate, the next film can follow the shape of submicron irregularities as long as the film thickness is below a certain level.

However, since the hydrolyzate of the silicon compound represented by the general formula (II) is difficult to penetrate inside the acrylic resin substrate, the mixing ratio (B
/A) becomes high, resulting in damage to the surface shape of the substrate. Therefore, in the present invention, the mixing ratio B/A
shall be B/A<0.5.

In the present invention, the acrylic resin molding on which the primary coating has been formed is treated by adding an organic colorant such as a dye or pigment to an aqueous solution of hydrosilicofluoric acid that is supersaturated with silicon dioxide. The acrylic resin molded product is colored by bringing it into contact with the liquid to form a silicon dioxide film containing an organic colorant on the surface of the acrylic resin molded product with the primary coating.

A method for obtaining a supersaturated silicofluoric acid solution of silicon dioxide is to dissolve and saturate silicon dioxide in a silicofluoric acid solution containing a metal containing an element that has a greater ionization tendency than boric acid, aqueous ammonia, or hydrogen.・It can also be obtained by adding additives that react with fluorine ions, such as metal halides, or by increasing the temperature of a hydrosilicofluoric acid solution saturated with silicon dioxide, as seen in JP-A-61-281○47. It can also be obtained by such means as

In addition, the organic colorant can be added directly to an aqueous solution of hydrosilicofluoric acid in which silicon dioxide is saturated or supersaturated, or it can be dissolved in water in advance and then added to the aqueous solution of hydrosilicofluoric acid. can.

Furthermore, it is also possible to dissolve the water-insoluble organic coloring agent in a water-soluble organic solvent in advance and then add it to the hydrosilicofluoric acid aqueous solution.

The concentration of hydrosilicofluoric acid is 1.5 to 3.5 mol/Q
is preferred, and examples of organic colorants include, for example, KAYACYL YELLOW GG [KAYACYL YELLOW GG].
(Nippon Kayaku), malachite green [MALACHI]
TEGREEN] (Hodogaya Chemical), Alizarine Astol [ALIZARINE ASTOL] (Tokyo Kasei)
, Methyl Violet Pure SP [MET]
IYL VIOLET PURE SP] (Hodogaya Chemical), Red 21 P S-011 [RED 21
PS-011 (Tokyo Kasei), Kayashiru Roda-kun F
B[KAYACYL RHODAMINE FBI (
Nippon Kayaku), Pictrif Heal7-Fh-BO
H[VICTORIA PURE BLUE,BO)I
] (Hodogaya Chemical), Bu/L, -5P R-006 [
BLUE 5P R-006 (Tokyo Kasei), red
3P T-016 [RED 3P T-016 (Tokyo Kasei), Victoria Blue BH [VICTORLA
BLUE B) I] (Hodogaya Chemical), Green 10
P P -005 [GREEN IOP P-00
5] (Tokyo Kasei), similar dyes, DIACELLITON FAST RED [DIACELLITON FAST
Dispersed pigment similar to RED Co (Mitsubishi Kasei), acridine red [ACRDIN RED], fluorescein [FL
UORESCEIN], Rhodamine B [RF(ODA
NINE B], Rhodamine 6G, Rhodamine 19,
Rhodamine 11010-Damine 116, Rhodamine 123, Sulforhodamine B [5tlLFOR)IO
DA former NE B], COtlMARI 6 [COtlMARI
Examples include laser dyes similar to N6].

By bringing the treatment liquid thus obtained into contact with the organic molded body with the primary coating, a colorant-containing silicon dioxide film is formed on the surface of the molded body, thereby achieving functional dyeing and coloring. Although it is possible to bring the treatment liquid into contact with the base material by letting the treatment liquid flow down onto the surface of the base material, it is easier to immerse the base material in a dipping tank filled with the treatment liquid. preferable. This is because, according to this method, a uniform colorant-containing silicon dioxide film can be obtained even on a substrate having a complicated shape. Further, the temperature of the treatment liquid when bringing the treatment liquid into contact with the substrate is sufficient to be around room temperature, and the upper limit thereof is not particularly limited, but is preferably about 35°C. This is because unnecessarily increasing the temperature of the treatment liquid may cause decomposition of the added organic colorant.

[Effect]

In this invention, since the organic colorant is uniformly present in the processing solution, a silicon dioxide thin film containing the organic colorant uniformly can be easily formed.

Since this film-forming reaction proceeds near room temperature, the organic colorant in the solution is uniformly incorporated into the film without being decomposed. Furthermore, this film is dense and adheres to the base material, so there is no need for heat treatment. Since the thin film is formed by precipitation from a supersaturated solution, impurities such as undecomposed raw materials and solvents are hardly mixed into the organic colorant-containing silicon dioxide thin film obtained by this invention. The starting materials of this invention are very cheap and there is no high temperature heat treatment process, so
The manufacturing cost of the membrane can be kept low.

Furthermore, since the reaction is carried out in a uniform solution, a uniform organic colorant-containing silicon dioxide thin film can be formed even on a substrate with a complicated shape.

〔Example〕

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 Ryo-methacryloxypropyltrimethoxysilane 1.5
g and C3GL-0803P (manufactured by Chisso (□), solid content concentration 8% (hydrolyzate of tetraethyl orthosilicate)
) 3 g of a mixture (D/C=0.22) of ethanol:isopropyl alcohol:n-butyl alcohol-5:3
:2 (volume ratio) solution dissolved in 250 ml of combined solvent (
Silicon compound concentration approximately 0.9% by weight), vertical and horizontal IQOmm
, an acrylic resin flat plate (extruded plate, number average molecular weight 57,000) with a thickness of 1.5 mm was immersed at a rate of 15 cm/min (
7) After being pulled up at high speed, it was dried at room temperature for 1 hour. When a primary film was formed on a glass substrate under the same conditions as the above operation, the film thickness was approximately 10 nm.

A colored layer made of a silicon dioxide film containing the organic colorant shown in Table 1 was formed on the obtained acrylic flat plate with the primary coating using the silicon dioxide film manufacturing apparatus shown in FIG.

In Table 1 and Figure 1, the immersion tank consists of an outer tank 1 and an inner tank 2, and the space between the inner tank 2 and the outer tank 1 is filled with water 3. This water is heated with a heater 4 to a temperature of 40° C., and is stirred to make the temperature distribution uniform. The inner tank 2 has a front part 6,
The middle part 7 and the rear part 8 are hollowed out, and each part is filled with 2.5 mol# hydrosilicofluoric acid aqueous solution 6.5 in which silicon dioxide is dissolved and saturated using industrial silica gel powder as a source of silicon dioxide.
It is full of floods. Furthermore, 1cc of a 5% by weight aqueous solution of the dye shown in Table 1 was added to the aqueous solution per 1000 C of hydrofluorosilicic acid. Coloring was carried out using each treatment solution containing each dye, and the treatment solution was replaced every time a series of operations were completed.

In each coloring operation, first, the circulation pump 10 is operated to pump out a certain amount of the reaction liquid from the rear part 8 of the inner tank and pass it through the filter 11.
The treated liquid was filtered and returned to the front part 6 of the inner tank, and circulation of the treated liquid was started.

Thereafter, an AQ plate 12 measuring 50 mm in length and width and 3 mm in thickness was immersed in the rear part 8 of the inner tank and held for 10 hours.

In this state, the reaction solution became a treatment solution having an appropriate degree of SiO2 supersaturation. Here, the absolute removal rate of filter 11 is 1.
5 μm, and the processing liquid circulation flow rate was 520 mQ/m1n (the total amount of processing liquid was approximately 6.5 mm, so the circulation flow rate was 8%/m1).
It is n. ) was adjusted. Then, the acrylic flat plate 9 on which the primary coating was formed with the silicon compound was immersed vertically into the inner tank middle part 7, and the circulation was performed at 8%/min under the above conditions (i.e., AQ, with the three plates immersed). After holding for 16 hours, it was taken out, washed and dried.

Table 1 shows the types of dyes added and the experimental results.

The thickness of the silicon dioxide film was measured using a contact needle type film thickness measuring device.

These organic dyes can be used for X-ray photoelectron spectroscopy (ESCA),
Secondary ion mass spectrometry (SIMS), infrared spectroscopy (I
As a result of analysis using methods such as R), it was confirmed that the membrane was uniformly incorporated into the membrane. Further, the substrate after the silicon dioxide film was immersed in a 99.5% alcohol solution for 24 hours, but no elution of the organic dye was observed.

Furthermore, the obtained organic colorant-containing silicon dioxide film had a strong adhesive force that could not be peeled off at all in a test in which a cellophane adhesive tape was applied and peeled off. Further, the acrylic resin substrate with the organic colorant-containing silicon dioxide coating was immersed in boiling water for 1 hour, but there was no change in the adhesion of the coating.

〔Effect of the invention〕

As detailed above, the method for producing an organic colorant-containing silicon dioxide-coated acrylic resin molded article of the present invention includes adding a silicon compound having a methacryloxy group represented by the general formula (1) on the surface of the acrylic resin molding, By coating and curing a mixture containing a specific proportion of a hydrolyzate of a silicon compound represented by (II), a very thin silicon-containing coating with good adhesion is coated as a primary coating, and then The first
This invention creates a silicon dioxide film containing an organic colorant that has good adhesion to the next film. The resulting organic colorant-containing silicon dioxide film has the effect of blocking the permeation of water vapor, oxygen, etc., and prevents the colorant from oxidation and hydrolysis. This prevents problems such as leaching and weakening of the degree of coloration.

(2) The obtained organic colorant-containing silicon dioxide coating has the effect of blocking the permeation of organic solvents and chemicals, and can improve the solvent resistance and chemical resistance of the colored layer.

■ Since the organic colorant has a structure protected by silicon dioxide, a colored layer with excellent wear resistance can be obtained.

A colored layer with extremely excellent durability and weather resistance can be obtained.

Furthermore, (1) the organic colorant-containing silicon dioxide film can be produced at around room temperature without heating at high temperatures, so it can be applied to organic colorants that are easily decomposed by heat.

■ In the coating method for forming the primary film, a dilute solution of a silicon compound can be used as the coating liquid, and the acrylic resin substrate has fine irregularities because the silicon compound diffuses into the acrylic resin. It is possible to coat the surface with a thin film without damaging its shape.

The effect of using it is also great.

[Brief explanation of drawings]

FIG. 1 is a system explanatory diagram of the silicon dioxide film manufacturing apparatus used in the examples. ↓ ・−・Outer tank, 2 ・・・・Inner tank, 3
... Water, 4 ... Heater 1 3 ... Stirrer, ... Middle part of inner tank, ... Polycarbonate molded body, ... - Filter ... mixer. 0 2 ...Front part of inner tank, ...Rear part of inner tank, ...Circulation pump, ...Metal aluminum plate

Claims (1)

[Scope of Claims] (1) After coating an acrylic resin molded body with an organosilicon compound and curing it to form a primary coating, the acrylic resin molded body with the primary coating and silicon dioxide are silicofluorinated in a supersaturated state. A method for producing a silicon dioxide-coated acrylic resin molded article, in which a silicon dioxide coating is formed on a primary coating by contacting with a hydrogen acid solution, the primary coating having a methacryloxy group represented by the general formula (I). A silicon compound and a hydrolyzate of the silicon compound represented by the general formula (II) are combined into R^lSiO of a silicon compound having a methacryloxy group represented by the general formula (I).
The ratio of the weight (A) in terms of _3_/_2 and the weight (B) in terms of SiO_2 of the silicon compound represented by the general formula (II) is 0.
A mixture containing 1<B/A<0.5 is coated and cured, and an organic coloring such as a dye or pigment is added to a supersaturated hydrosilicofluoric acid solution of silicon dioxide on the first film. 1. A method for coloring an acrylic resin molded article, which comprises bringing into contact a treatment liquid containing an organic colorant to form a silicon dioxide film containing an organic colorant. R^lSi(R^2)_3(I) Si(R^3)_4 (II) (In the formula, R^l is an organic group having a methacryloxy group, and R^2 and R^3 are an alkoxy group, one or more bonding groups selected from alkoxyalkoxy groups, acetoxy groups, and chlorine elements.) (2) Claim 1, wherein the acrylic resin molded product has a number average molecular weight of 80,000 or less. A method for coloring acrylic resin molded objects. (3) Claim 1, wherein the conditions for creating the first film are such that a film with a thickness of 5 to 50 nm is created when the film is created on a glass substrate under similar conditions. Or the method for coloring an acrylic resin molded article according to item 2. (4) The primary coating is formed by applying a coating solution containing 0.5 to 3% by weight of a silicon compound and drying it. The method for coloring an acrylic resin molded article described in . (5) A supersaturated silicofluoric acid aqueous solution of silicon dioxide dissolves and saturates silicon dioxide in a silicofluoric acid solution containing boric acid, aqueous ammonia, and metals consisting of elements that have a greater ionization tendency than hydrogen. The method for coloring an acrylic resin molded article according to any one of claims 1 to 4, which is an aqueous solution in which silicon dioxide is supersaturated by adding an additive such as a halide that reacts with fluorine ions. . (6) The supersaturated solution of silicon dioxide is an aqueous solution in which silicon dioxide is dissolved and saturated at a low temperature and then heated and maintained at a high temperature to make the silicon dioxide a supersaturated state. The method for coloring an acrylic resin molded article according to any one of Item 4. (7) Claims 1 to 4, wherein the organic coloring agent added to the supersaturated aqueous solution of hydrosilicofluoric acid of silicon dioxide is dissolved in water or a water-soluble organic solvent in advance. The method for coloring an acrylic resin molded article according to any one of the items.