JP3216262B2 - Heat-curable anti-fog composition for vehicle lighting and vehicle lighting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-curable anti-fog composition for a vehicle lamp mounted on an automobile or the like and a vehicle lamp. More specifically, a heat-curable anti-fogging agent composition applied to the inner surface of a plastic lens or the like in a vehicle lamp which is exposed to a high temperature environment of 60 to 140 ° C. during use, and the heat-curing anti-fog agent composition The present invention relates to a vehicle lighting device obtained by applying an object.

[0002]

2. Description of the Related Art The present inventors have proposed the following antifogging agent as a method for imparting antifogging properties to various transparent plastic materials (JP-A-2-255854). That is,
The first is an antifogging agent comprising a block or graft copolymer comprising a hydrophilic polymer portion and a hydrophobic polymer portion and a surfactant. The second consists of a hydrophobic polymer portion and a hydrophilic polymer portion formed from an acrylamide derivative,
An antifogging agent containing a block or graft copolymer having self-crosslinking properties and a surfactant. Thirdly, it is composed of a hydrophobic polymer portion, a acrylamide derivative and a hydrophilic polymer portion formed from hydroxyalkyl (meth) acrylate, and contains a self-crosslinkable block copolymer and a surfactant. It is an antifogging agent for polyester.

On the other hand, anti-fogging of a vehicle lamp has a very long time even in a high temperature environment when the lamp is used, that is, at a temperature of 60 to 140 ° C. Are required as basic performance.

[0004]

However, in the case of an antifogging agent comprising a surfactant or a block or graft copolymer having a specific composition having self-crosslinking properties and a surfactant according to the present inventors, a normal temperature range is required. The appearance, antifogging property, adhesiveness, and coating film strength in an environment of -20 to 60 ° C or less are maintained for an extremely long time. However, in a high temperature environment, that is, 60 to 1
At a temperature of 40 ° C., the anti-fogging coating has a problem that its anti-fogging property and adhesiveness decrease with time. Therefore, even in such a high-temperature environment, as in a normal environment, a practically usable appearance, adhesion, antifogging property and antifogging agent composition and coating method in which the coating film strength is maintained for a long period of time. Development was strongly sought.

The present invention has been made in view of the above-mentioned problems of the prior art, and the object thereof is to achieve, in particular, 60 to
By improving the antifogging property and the adhesion in a high temperature environment of 140 ° C., the actual usage environment of the vehicle lamp is -20 to 20.
At a temperature of 140 ° C., a heat-curable anti-fogging agent composition for a vehicle lamp capable of exhibiting excellent anti-fogging property, adhesion, coating strength and coating appearance for a long period of time, and this anti-fogging composition were applied. A vehicle lighting device is provided.

[0006]

Means for Solving the Problems In order to achieve the above-mentioned object, the present inventors have proposed an anti-fogging coating film proposed by the present inventors in a high-temperature environment of 60 to 140 ° C. The cause of the decrease in the adhesiveness and adhesion was examined. As a result, when the coating film is placed in a high temperature environment of 60 to 140 ° C., the crosslinking reaction of the anti-fogging coating film proceeds, the crosslinking density increases with time, and the penetration of water into the coating film increases. The anti-fogging property decreased over time because it was lower than the initial time.

[0007] On the other hand, the adhesiveness is lowered because the internal stress is accumulated in the coating film due to the progress of the crosslinking reaction over time, and the coating film cannot follow the expansion of the substrate. The factors that promote the crosslinking reaction of this coating film were the following two points. That is, the first point is that the hydrophilic monomers having a hydroxyl group forming the hydrophilic polymer portion of the block or graft copolymer react with each other. The second point is that a glycidyl group, an N-methylol group, which constitutes a hydrophilic polymer portion,
N-methylol ether group, carboxyl group, glycidyl group constituting a hydrophobic polymer portion and a vinyl-type monomer having a cross-linking functional group of any of an acid anhydride group, N-methylol group, N-methylol ether group, A coating film that can be used practically without any cross-linking functional group reacting during the formation of an antifogging coating film when a crosslinking reaction with a vinyl-type monomer having a crosslinking functional group of either a carboxyl group or an acid anhydride group is performed. A cross-linking reaction that develops strength occurs, and unreacted cross-linking functional groups further react in a high-temperature environment of 60 to 140 ° C.

[0008] The present inventors have removed the above two factors that reduce the anti-fogging property and the adhesion in a high-temperature environment while utilizing the previously proposed technology, As a result of intensive studies on the adjustment of hydrophilicity and hydrophobicity of the copolymer, the present invention was completed.

That is, the heat-curable anti-fogging composition for a vehicle lamp according to the first invention of the present invention is represented by the formula (1) or (2) by weight of 1 to 15% by weight of N-methylol (meth) acrylamide. 35 to 86% by weight of at least one of N-substituted or unsubstituted (meth) acrylamide-based compounds
And a hydrophilic polymer portion formed from 15 to 50% by weight of at least one or more of lower alkyl (meth) acrylate, and 1 to 30% by weight of a vinyl type monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group. And a hydrophobic polymer portion formed from 70 to 99% by weight of a lower alkyl (meth) acrylate copolymerizable with the vinyl-type monomer, wherein the hydrophilic polymer portion and the hydrophobic polymer portion Is characterized by containing a block or graft copolymer having a weight ratio of 50/50 to 95/5.

In a second aspect of the present invention, there is provided a heat-curable anti-fogging composition for a vehicle lamp, wherein the block or graft copolymer has a hydrophilic polymer portion of 1 to 15% by weight of N-methylol (meth) acrylamide. %, The general formula 1 or 2
20 to 79% by weight of at least one kind of N-substituted or unsubstituted (meth) acrylamide-based compound represented by the formula: and at least one kind of lower alkyl (meth) acrylate 15
And at least one kind of the lower alkoxyalkylene glycol (meth) acrylate represented by the above general formula (3) and 5 to 50% by weight.

Further, the heat-curable anti-fogging agent composition for a vehicle lamp according to the third invention is obtained by mixing a surfactant with the heat-curing anti-fogging agent composition for a vehicle lamp according to the first or second invention, The blend ratio of the block or graft copolymer and the surfactant is 100: 0.5 to 30 in terms of solids weight ratio. A vehicle lighting device according to a fourth aspect of the present invention comprises applying the heat-curable anti-fog agent composition for a vehicle lighting device according to the first to third aspects to a base material,
It is characterized by being formed by heating and curing at a temperature of 45 ° C. to form an antifogging coating film on the surface.

Next, the present invention will be sequentially described in detail. First, the block or graft copolymer in the present invention will be described. The hydrophilic polymer portion of the block or graft copolymer is composed of 1 to 15% by weight of N-methylol (meth) acrylamide, of the N-substituted or unsubstituted (meth) acrylamide-based compound represented by Chemical Formula 1 or Chemical Formula 2. 35 to 86% by weight of at least one kind, 15 to 50% by weight of at least one kind of lower alkyl (meth) acrylate, or 1 to 15% by weight of N-methylol (meth) acrylamide, N represented by
20 to 79% by weight of at least one kind of substituted or unsubstituted (meth) acrylamide-based compound, 15 to 50% by weight of at least one kind of lower alkyl (meth) acrylate, lower (meth) acrylic acid represented by the above formula (3) It is composed of 5 to 50% by weight of at least one kind of alkoxyalkylene glycol.

In order to maintain the adhesion between the coating film exhibiting anti-fogging property and the substrate in a high temperature environment of a temperature range of 60 to 140 ° C. for a long period of time and to develop practical coating film strength, it is necessary to use a single monomer. It is necessary to use N-methylol (meth) acrylamide as a body. Further, the crosslink density can be adjusted to an optimum value by its abundance.
5% by weight. If the amount is less than 1% by weight, the crosslink density of the coating film is insufficient and sufficient coating film strength cannot be obtained. Meanwhile, 1
If it exceeds 5% by weight, the crosslinking density becomes too high and the anti-fogging property is lowered, and the adhesion to the substrate in the initial stage and in a high-temperature environment of 60 to 140 ° C. is also lowered.

Further, the hydrophilic polymer portion comprises N-methylol (meth) acrylamide as a monomer constituting the hydrophilic polymer portion and an N-substituted or unsubstituted (meth) acrylamide-based compound represented by the above formula (1) or (2). In the case of a component system comprising at least one or more compounds and at least one or more lower alkyl (meth) acrylates, at least one or more N-substituted or unsubstituted (meth) acrylamide-based compounds 35
~ 86% by weight. On the other hand, N-methylol (meth) acrylamide, at least one or more N-substituted or unsubstituted (meth) acrylamide-based compounds represented by Chemical Formula 1 or Chemical Formula 2, and at least one or more of lower alkyl (meth) acrylates And, in the case of a component system composed of at least one of the lower alkoxyalkylene glycol (meth) acrylates represented by the above formula 3, at least one or more of the N-substituted or unsubstituted (meth) acrylamide-based compounds and 20 to 79% by weight. Be composed.

In particular, by using at least one monomer of the N-substituted or unsubstituted (meth) acrylamide-based compound represented by the above formula (1) or (2), the initial state of the coating film and 60 to 140 ° C. The excellent antifogging property under a high temperature environment is maintained for a long time. In each component system,
When the amount of this monomer is less than 35% by weight or 20% by weight, the antifogging property in the initial stage and under a high temperature environment is reduced. On the other hand, if it exceeds 86% by weight or 79% by weight, the water penetration into the coating film becomes too strong, and the coating film strength decreases.

Examples of the N-substituted or unsubstituted (meth) acrylamide compound represented by the above formula 1 or 2 include (meth) acrylamide, N-methyl (meth) acrylamide, N, N'-dimethyl (meth) ) Acrylamide, N-ethyl (meth) acrylamide, N, N′-diethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N, N′-dimethylaminopropyl (meth) )
Acrylamide, diacetone (meth) acrylamide,
N- (meth) acryloylpiperidine, N- (meth) acryloylmorpholine and the like can be used. These monomers and any of the following monomers can be obtained as commercial products, and those synthesized according to known methods can also be used.

Further, the hydrophilic polymer portion may be a first or a second polymer.
In any of the inventions, in order to ensure adhesion and coating strength in a high-temperature environment, it is necessary to blend at least one or more lower alkyl (meth) acrylates that have not been blended conventionally. Content is 15 ~
It is in the range of 50% by weight. When the amount of this monomer is less than 15% by weight, the coating film strength in a high-temperature environment of 60 to 140 ° C. is insufficient. On the other hand, if it exceeds 50% by weight, the lower alkyl (meth) acrylate is hydrophobic, so that the hydrophilicity of the coating film is reduced and the antifogging property in the initial or high temperature environment is reduced.

Examples of the lower alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, and (meth) acrylic. Acid n-
Butyl, i-butyl (meth) acrylate, t-butyl (meth) acrylate and the like can be used.

The hydrophilic polymer portion contains at least one kind of the lower alkoxyalkylene glycol (meth) acrylate represented by the above formula (3) in the second invention and at least 5 to 50% by weight. This monomer has a slightly lower hydrophilicity than the N-substituted or unsubstituted (meth) acrylamide-based compound represented by the above formula 1 or 2, and has a lower hydrophobicity than the lower alkyl (meth) acrylate. It is used for the purpose of adjusting the hydrophilicity and hydrophobicity of the hydrophilic polymer because it has properties, and for the purpose of suppressing the reactivity with the N-methylol group because the hydroxyl group is blocked with an alkyl group. .

That is, when the proportion of the N-substituted or unsubstituted (meth) acrylamide-based compound represented by Chemical Formula 1 or Chemical Formula 2 in the monomer constituting the hydrophilic polymer portion is high, By replacing a part of the above with the lower alkoxyalkylene glycol (meth) acrylate represented by the above formula 3, the anti-fogging property can be improved without greatly lowering the strength of the coating film in the initial and high-temperature environments. Can be.
If the amount of the monomer is less than 5% by weight, the anti-fogging property of the coating film is insufficient, and if it exceeds 50% by weight, the strength of the coating film is insufficient.

As the lower alkoxyalkylene glycol (meth) acrylate represented by the above formula 3, methoxyethylene glycol (meth) acrylate (where
n is preferably an integer of 1 to 10, ethoxyethylene glycol (meth) acrylate (where n is 1 to 10)
Are preferred), and methoxypropylene glycol (meth) acrylate (where n is preferably an integer of 1 to 10), and the like.

Next, the hydrophobic polymer portion of the block or graft copolymer will be described. This hydrophobic polymer portion is composed of 1 to 30% by weight of a vinyl type monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group and 70 to 99% by weight of a lower alkyl (meth) acrylate copolymerizable therewith. %. When the amount of the vinyl type monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group is less than 1% by weight, the transparency of the coating film is reduced. When it exceeds 30% by weight, the adhesion between the coating film and the substrate is reduced. I do. Further, this monomer also functions as an acid catalyst at the time of a crosslinking reaction of N-methylol (meth) acrylamide in the hydrophilic polymer portion. The crosslinking reaction mainly occurring in the present invention is based on N-
This is a crosslinking reaction between methylol (meth) acrylamides.

Examples of this monomer include 3-sulfopropyl (meth) acrylate and (meth) acrylic acid-2
-Sulfoethyl, 2-acrylamido-2-methylpropanesulfonic acid, (meth) acrylic acid, crotonic acid, itaconic acid, itaconic acid half ester, maleic acid half ester, maleic acid, mono (2- (meth) acryloyloxyethyl) Acid phosphate or the like can be used.

The copolymerizable lower alkyl (meth) acrylate is a lower alkyl (meth) acrylate having a linear or branched alkyl group having 1 to 4 carbon atoms. When the proportion of the monomer is less than 70% by weight, the adhesion between the coating film and the substrate is reduced, and when it exceeds 99% by weight, the transparency of the coating film is reduced. As the monomer, the lower alkyl (meth) acrylate described above is used.

Next, it is necessary that the weight ratio of the hydrophilic polymer portion to the hydrophobic polymer portion in the block or graft copolymer is from 50/50 to 95/5. When the proportion of the hydrophilic polymer portion is less than 50% by weight, the hydrophilicity of the block or graft copolymer is reduced, and the interaction between the block or graft copolymer and the surfactant is weakened. Not only the antifogging property but also the antifogging durability decreases. On the other hand, when the ratio of the hydrophobic polymer portion is less than 5% by weight, the strength of the coating film and the adhesion to the substrate are impaired.

The block or graft copolymer comprising a hydrophilic polymer portion and a hydrophobic polymer portion according to the present invention can be synthesized by a conventionally known method. From the standpoint, those produced by a radical polymerization method using a polymeric peroxide, a polyazo compound, or a radical copolymerized peroxide as a polymerization initiator are preferable. In this case, as the radical polymerization initiator to be used, a conventionally known compound having two or more peroxy bonds or azo bonds in one molecule, and a compound having a radical copolymerizable group and a peroxy bond in one molecule are used. As the polymerization method, a usual bulk polymerization method, suspension polymerization method, solution polymerization method, emulsion polymerization method and the like are employed.

Next, as a typical production example of the block copolymer of the present invention, a polymerization method using a polymeric peroxide as a polymerization initiator will be described below. First, when a monomer forming a hydrophilic polymer portion is polymerized using a polymeric peroxide, a peroxy bond-containing hydrophilic polymer having a peroxy bond introduced into a chain is obtained. When a monomer that forms a hydrophobic polymer portion is added thereto and polymerization is performed, cleavage occurs at a peroxy bond in the hydrophilic polymer chain, and a block copolymer can be obtained efficiently.

Further, a typical production example of the graft copolymer of the present invention will be described using a radical copolymerizable group-containing peroxide as a polymerization initiator. First, a peroxy bond is contained by copolymerizing a vinyl-type monomer that forms a hydrophilic polymer with a normal free radical polymerization initiator under the condition that the peroxy bond of the radical copolymerizable group-containing peroxide is not cleaved. A hydrophilic copolymer is obtained. Next, under the condition that this peroxy bond is cleaved, when a vinyl-type monomer forming a hydrophobic polymer is added thereto and polymerization is performed, the peroxy bond in the hydrophilic polymer is cleaved and the graft is efficiently grafted. A copolymer is obtained. In the block or graft copolymer synthesized in this way, the molecular weights of the hydrophilic polymer portion and the hydrophobic polymer portion can be freely adjusted.

Next, a surfactant is blended in the heat-curable anti-fogging composition of the third invention. The surfactant is generally used, and may be one or more surfactants selected from nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants. Agent. Among these, nonionic surfactants or anionic surfactants are preferred from the viewpoint of the persistence of the effect, and in particular, the combination of polyoxyethylene alkylaryl ethers and dialkyl sulfosuccinates has a long antifogging property. It is suitable from the viewpoint of preventing the property and appearance change of the coating film.

Examples of the nonionic surfactant include polyoxyethylene higher alcohol ethers such as polyoxyethylene lauryl alcohol, polyoxyethylene lauryl ether and polyoxyethylene oleyl ether, polyoxyethylene octyl phenol, polyoxyethylene nonyl phenol and the like. Polyoxyethylene alkyl aryl ethers, polyoxyethylene acyl esters such as polyoxyethylene glycol monostearate, polypropylene glycol ethylene oxide adducts, polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monostearate and other polyoxyethylene acyl esters Oxyethylene sorbitan fatty acid esters, alkyl phosphates, polyoxyethylene alkyl ether phosphates Phosphoric acid esters such as Le, sugar esters, cellulose ethers are used.

Examples of the anionic surfactant include fatty acid salts such as sodium oleate and potassium oleate, higher alcohol sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium alkylnaphthalenesulfonate. And the like. Alkyl benzene sulfonates and alkyl naphthalene sulfonates, naphthalene sulfonic acid formalin condensates, dialkyl sulfosuccinates, dialkyl phosphate salts, polyoxyethylene sulfate salts such as sodium polyoxyethylene alkyl phenyl ether sulfate are used.

Examples of the cationic surfactant include amine salts such as ethanolamines, laurylamine acetate, triethanolamine monoformate, and stearamidoethyldiethylamine acetate, lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, and diamine. Lauryl dimethyl ammonium chloride, distearyl dimethyl ammonium chloride,
Quaternary ammonium salts such as lauryl dimethyl benzyl ammonium chloride and stearyl dimethyl benzyl ammonium chloride are used.

Examples of the amphoteric surfactant include fatty acid type amphoteric surfactants such as dimethylalkyl lauryl betaine and dimethylalkyl stearyl betaine, sulfonic acid type amphoteric surfactants such as dimethyl alkyl sulfobetaine, and alkyl glycine. used.

The mixing ratio of these surfactants is represented by the weight ratio of solid content, that is, block or graft copolymer: surfactant = 1.
00: 0.5 to 30. When the amount of the surfactant is 0.
If the amount is less than 5 parts by weight, the long-lasting anti-fogging property cannot be obtained, and if it exceeds 30 parts by weight, the water resistance and the strength of the coating film become low.

As a method for mixing the block or graft copolymer and the surfactant, the block or graft copolymer is dissolved or dispersed in an organic solvent or a mixed solvent of water and an organic solvent or dispersed in water. A surfactant may be added therein, or a surfactant may be added together with a monomer which forms a block or graft copolymer.

The solvent used in this case includes water, alcoholic solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, diacetone alcohol, methyl cellosolve, ethyl cellosolve, and the like.
Alcohol ether solvents such as butyl cellosolve, methyl carbitol, ethyl carbitol and butyl carbitol; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as methyl acetate, ethyl acetate and butyl acetate; benzene, toluene and xylene And amide solvents such as formamide and dimethylformamide. Of these, alcohol solvents, alcohol ether solvents and mixed solvents thereof are particularly preferred.

In the heat-curable anti-fogging composition of the present invention, various conventional additives such as an ultraviolet absorber, a leveling agent, a curing catalyst, an antioxidant and the like can be blended if necessary.

Next, anti-fog processing of a vehicle lamp using the heat-curable anti-fog agent composition for a vehicle lamp of the present invention will be described. That is, the inner surface of the plastic lens of the lamp is coated by a coating means using a normal paint,
A coating film is formed by heating and curing at a temperature of ° C. As the plastic lens, a lens made of polycarbonate, polymethyl methacrylate, or the like is used.
By this anti-fog processing, vehicle lighting incorporating a plastic lens provided with anti-fog properties, under actual use environment,
Not only the appearance and adhesion of the coating film, but also the antifogging property and the coating film strength are maintained for an extremely long time.

As a coating environment, the relative humidity is 60%.
R. H. The following is preferred. This is because the antifogging agent composition of the present invention has a very high hydrophilicity and tends to absorb water. That is, a relative humidity of 60% R.
H. When the coating is performed in an environment exceeding the above range, the coating film tends to whiten after heat curing and the appearance tends to deteriorate. In order to suppress this tendency of whitening, it is effective to partially use a solvent having a small amount of water adsorbed during evaporation of the solvent and having a low evaporation rate.

As a coating means, a coating means in a usual paint, that is, a roll coating method, a spray method, a dipping method, a brush coating method, a spin coating method, a flow coating method, a bar coater method or the like is applied.

[0041]

The present invention will be specifically described below with reference to examples and comparative examples. All copies are based on weight. (Reference Examples 1 to 15) (Synthesis of Block Copolymer) A block copolymer was synthesized as follows by two-stage polymerization using a polymeric peroxide represented by the following formula 4 as a polymerization initiator. In addition, the polymerization conditions shown below are as follows. In each of the first-stage polymerization for forming the hydrophilic polymer portion and the second-stage polymerization for forming the hydrophobic polymer portion, the charged monomers are almost completely in each stage. This is the condition for polymerization.

[0042]

## STR4 ##-[CO (CH ₂ ) ₄ COO (C ₂ H ₄ O) ₃
CO (CH ₂ ) ₄ COOO] ₁₀ -Methyl cellosolve 100 was added to a reactor equipped with a thermometer, a stirrer, and a reflux condenser.
And heated to 70 ° C. while blowing in nitrogen gas. Then, methylcellosolve A part Polymeric peroxide B part shown by chemical formula 4 N-methylol (meth) acrylamide C part compound 1 shown by chemical formula 1 or compound D part A mixed solution composed of a compound F part represented by lower alkyl (meth) acrylate E part 3 was charged over 2 hours, and a polymerization reaction was further performed for 2 hours (first-stage polymerization). Thereafter, a mixed liquid consisting of a methylcellosolve G part, a vinyl-type monomer having a sulfonic acid group, a carboxyl group, or a phosphoric acid group, H part, a lower alkyl (meth) acrylate I part, was charged over 30 minutes, and then charged at 75 ° C. The polymerization reaction was performed for 5 hours. Tables 1 to 3 show the number of parts of A to I and the polymerization results. (Reference Examples 16 to 27) (Synthesis of Graft Copolymer) A graft copolymer was synthesized using t-butylperoxymethacryloyloxyethyl carbonate. In addition, the polymerization conditions shown below are the first conditions for forming the hydrophilic polymer portion.
The conditions are such that the charged monomers are almost completely polymerized at each stage of the stage polymerization and the second stage polymerization for forming the hydrophobic polymer.

First, 100 parts of methyl cellosolve was charged into the reactor used in Reference Example 1 and heated to 85 ° C. while blowing nitrogen gas. Then, 33.6 parts of methyl cellosolve was added to t-butyl peroxyoctanoate. 0 parts t-butylperoxymethacryloyloxyethyl carbonate 2.4 parts N-methylol (meth) acrylamide C part Compound represented by the formula 1 or 2 D part Lower alkyl (meth) acrylate E part Compound represented by the formula 4 The mixed solution composed of Part F was charged over 2 hours, and a polymerization reaction was further performed for 7 hours (first-stage polymerization). After that, 110
The mixture was heated to 30 ° C., and a mixed liquid consisting of methylcellosolve G, a vinyl-type monomer having a sulfonic acid group, a carboxyl group, or a phosphoric acid group, H part, lower alkyl (meth) acrylate, I part, was charged over 30 minutes. The polymerization reaction was performed at 110 ° C. for 7 hours. Tables 4 and 5 show the numbers of C to I and the polymerization results. (Reference Examples 28 to 30) (Synthesis of random copolymer) Methyl cellosolve 10 was added to the reactor used in the synthesis of Reference Example 1.
0 parts were charged and heated to 85 ° C. while blowing in nitrogen gas. Then, methylcellosolve 36 parts t-butylperoxyoctanoate 4 parts N-methylol (meth) acrylamide C part Compound D represented by Chemical formula 1 or Chemical formula 2 Part: a lower alkyl (meth) acrylate E part: a compound represented by the formula (3): G: a vinyl monomer having a sulfonic acid group, a carboxyl group or a phosphoric acid group: H part: a lower alkyl (meth) acrylate: I part Was charged over 2 hours, and a polymerization reaction was further performed for 9 hours. Table 6 shows the number of parts of C to I and the polymerization results.
It was shown to.

The abbreviations in Tables 1 to 6 have the following meanings. N-MAAm: N-methylolacrylamide DMAAm: N, N′-dimethylacrylamide ACMO: N-acryloylmorpholine MMA: methyl methacrylate IBMA: i-butyl methacrylate M20G: methoxydiethylene glycol methacrylate M40G: methoxytetraethylene glycol methacrylate AA : Acrylic acid MAA: Methacrylic acid SEM: 2-sulfoethyl methacrylate MC: Methyl cellosolve The solid content in the column of the polymerization result represents% by weight. The viscosity represents the viscosity (poise, P) at 25 ° C. of the polymerization solution. The ratio of the hydrophilic polymer represents the ratio (%) of the polymer synthesized in the first-stage polymerization to the total amount of the polymer.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

[0048]

[Table 4]

[0049]

[Table 5]

[0050]

[Table 6]

(Examples 1 to 20 and Comparative Examples 1 to 13) For a vehicle lighting device, all of the polymers synthesized in Reference Examples 1 to 30 were diluted with methyl cellosolve so that the solid content of the polymer was 20% by weight. A surfactant was added to the heat-curable antifogging composition and the diluted polymer solution to obtain a heat-curing antifogging composition for vehicle lighting. The composition was shown in Tables 7-9. Then, each composition was dried at a relative humidity of 60% R.sub.R so that the dry film thickness was 5 .mu.m. H. The composition was applied to a substrate using a bar coater under the following environment, and heat-cured under each condition. The abbreviations in Tables 7 to 9 represent the following meanings.

Surfactant (a): polyoxyethylene nonyl phenyl ether, trade name Nonion NS-212 manufactured by NOF Corporation (b): polyoxyethylene octyl phenyl ether,
Nonion HS-210 (trade name) manufactured by Nippon Yushi Co., Ltd .: sodium n-dodecylbenzenesulfonate, trade name NUREX® (trade name) manufactured by Nippon Yushi Co., Ltd. (d): Sodium dioctyl sulfosuccinate, trade name of Nippon Yushi Co., Ltd. B80 (e): Octadecyltrimethylammonium chloride, trade name Cation AB manufactured by NOF Corporation (f): Dimethylalkyl palm betaine, trade name Anon BF manufactured by NOF Corporation Base material PC: polycarbonate, PMMA: polymethyl methacrylate cured Conditions (1): 80 ° C for 60 minutes, (2): 120 ° C for 30 minutes, (3): 14
10 minutes at 0 ° C

[0053]

[Table 7]

[0054]

[Table 8]

[0055]

[Table 9]

The physical properties of the thus obtained coating films were evaluated by the following evaluation methods. The results are shown in Tables 10 to 14. (1) Adhesion A cross-cut cellophane tape peeling test was performed according to JIS D0202. That is, 100 crosscuts are made on the surface of the coating film with a cutter knife to reach the base material, a cellophane adhesive tape (manufactured by Nichiban Co., Ltd.) is affixed, peeled in the direction perpendicular to the adhesive surface, and the crosscuts remaining without peeling Are represented by the following symbols. (a): 100/100, (b): 30/100, (c): 1
5/100, (d): 0/100 (2) Coating Strength The change in the appearance of the coating film left in each environment was visually determined.

：: No change in appearance, ×: Change in appearance (3) Breath test The coating film left in each environment was placed in a constant temperature room at 20 ° C.
Breathing was applied to the coating film, and the cloudiness was visually determined.

◎: No clouding at all, ○: Water droplets spread instantaneously, Δ: Slightly cloudy, X: Cloudy over the entire surface (4) 60 ° C. steam test Coating in a constant temperature room at 20 ° C. Exposing the membrane to 60 ° C hot steam,
The time until clouding began was measured. Tables 10 to 14
In “≧ 5”, it means that it is 5 hours or more,
"Immediately" means that the cloud is immediately clouded.

Next, the environmental conditions of the test pieces subjected to each of the above tests are shown below. (A) Initial stage: physical properties of the coating film immediately after drying by heating (B) Moisture resistance: The coating film was dried at 50 ° C. and a relative humidity of 98% RH. H.
Properties of the coating film after standing for 300 hours in an environment (C) Cooling / heat cycle resistance: The coating film was heated at 120 ° C for 15.5 hours, room temperature for 30 minutes, -30 ° C for 7.5 hours, and room temperature for 3 hours.
The condition of leaving each for 0 minutes is one cycle,
(D) Heat resistance: 120 ° C when the substrate is polycarbonate
In the case where the substrate is polymethyl methacrylate,
Table 10 shows the evaluation results under each environment from (A) to (D) after leaving for 000 hours.
The results are shown in FIG.

[0060]

[Table 10]

[0061]

[Table 11]

[0062]

[Table 12]

[0063]

[Table 13]

[0064]

[Table 14]

As shown in the above Tables 1 to 14, those in which the hydrophilic polymer portion of the block or graft copolymer does not contain a portion formed from a predetermined range of monomers (Comparative Examples 1 and 3) -8) and those in which the weight ratio of the hydrophilic polymer portion to the hydrophobic polymer portion is not within the predetermined range (Comparative Example 2,
9) is inferior in any of antifogging property, adhesiveness and coating film strength.
Further, those using a random copolymer (Comparative Examples 10 to 10)
12) is extremely poor in antifogging property and adhesion. When the surfactant was added in an amount larger than the predetermined amount (Comparative Example 13), the coating film strength was deteriorated.

On the other hand, the heat-curable anti-fogging agent compositions of the respective examples have excellent initial anti-fogging properties,
The physical properties do not change even when left in an environment at 1000C or 90C for 1000 hours. In addition, it can be seen that the antifogging property is maintained for a long time by using a surfactant in combination, and a combination of a polyoxyethylene alkylaryl ether and a dialkyl sulfosuccinate is particularly preferable (for example, Example 8,
9, 14, 19, 20 and Examples 1, 17). (Examples 21 to 23) Next, the influence of the relative humidity in the coating environment on the appearance of the coating film was tested. Table 15 shows the formulation of the antifogging agent composition used. The polymer used here was diluted to a solid content of 20% with Reference Example 9 having a good result in the tests of Tables 10 to 14 with a mixed solvent of ethyl cellosolve having a lower evaporation rate than methyl cellosolve, and a surfactant was used. Was added to obtain a heat-curable antifogging composition for vehicle lighting. Table 1
In 5, the methyl cellosolve was MC and the ethyl cellosolve was E
Expressed as C.

[0067]

[Table 15]

Examples 24 to 35 The antifogging compositions shown in Table 15 were used at a relative humidity of 45 to 80% R.P. H. Was applied in a coating environment of 5 μm to a dry film thickness of 5 μm, and the change in the appearance of the coating film was evaluated by a haze value before and after coating. Table 16 shows the evaluation results. The abbreviations described for the base material and the curing conditions are the same as those described above.

The appearance of the coating film was evaluated according to the following criteria. ◎: Difference in haze value before and after coating is less than 0.5% ：: Difference in haze value before and after coating is 0.5% or more and less than 1.0% Δ: Difference in haze value before and after coating is 1. 0% or more and less than 1.5% ×: Difference in haze value before and after coating is 1.5% or more

[0070]

[Table 16]

(Examples 36 to 39 and Comparative Examples 14, 1
5) Examples 8, 14, 1 whose physical properties were good under each of the above-mentioned environments
9 and 20, the relative humidity of 60% R.R. H. The coating was applied by a spray method or a flow coating method so as to have a dry film thickness of 5 μm under the following environment, and cured by heating to form an anti-fog coating film. This anti-fog lens was assembled into a lamp and mounted on an actual car. Tables 17 and 18 show the coating conditions.

[0072]

[Table 17]

[0073]

[Table 18]

Examples 36 to 39 and Comparative Examples 14 and 15
Was actually mounted on a car and tested for 6 months. During this period, the ambient temperature rose to 60-140 ° C. As a result, the lamps of Comparative Examples 14 and 15 which were not subjected to the anti-fogging process were fogged, whereas the lamps of Examples 36 to 39 were not fogged, and the coating film appearance and coating film Adhesion did not decrease.

Accordingly, the heat-curable anti-fog composition for vehicle lighting of the present invention is suitable for imparting anti-fog properties to the inner surface of the lens of vehicle lighting for a very long time.

[0076]

As described in detail above, the heat-curable anti-fogging agent compositions for vehicle lamps of the first to third aspects of the present invention are particularly suitable for use in the range of 60 to 14%.
By improving the anti-fog property and adhesion in a high temperature environment of 0 ° C, excellent anti-fogging property, adhesion, coating strength and coating appearance that are initially exhibited under the actual use environment of vehicle lighting fixtures. Has an excellent effect that it is favorably maintained for an extremely long time. Further, according to the second aspect, it is possible to easily adjust the hydrophilicity and the hydrophobicity and adjust the crosslink density, and it is possible to improve the anti-fogging property without lowering the coating film strength.

According to the third aspect of the invention, there is an effect that the anti-fogging continuity can be maintained for a long time and the appearance of the coating film can be well maintained. Further, the vehicle lighting device of the fourth invention is sufficient for practical use by applying the anti-fogging agent composition to the inner surface of the lamp lens, heating and curing at 70 to 145 ° C. to perform anti-fogging processing. An excellent effect is obtained that the antifogging property that can be endured is maintained for an extremely long period, and the appearance, adhesion and strength of the formed antifogging coating film are also maintained.

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C08F 293/00 F21Q 1/00 E (72) Inventor Hiroshi Omura 5-3-1 Sanukiyama, Taketoyo-cho, Chita-gun, Aichi Prefecture 1 56) References JP-A-3-223370 (JP, A) JP-A-3-221566 (JP, A) JP-A-3-221565 (JP, A) JP-A-2-255854 (JP, A) JP JP-A-2-102278 (JP, A) JP-A-2-102277 (JP, A) JP-A-2-11673 (JP, A) JP-A-5-310972 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) C09D 5/00 C09D 101/00-201/10 C09K 3/18 101

Claims (4)

(57) [Claims] 1 to 15% by weight of N-methylol (meth) acrylamide, N represented by the following general formula 1 or 2
A hydrophilic polymer portion formed of at least one or more 35 to 86% by weight of a substituted or unsubstituted (meth) acrylamide-based compound and at least one or more of 15 to 50% by weight of a lower alkyl (meth) acrylate; Group,
Vinyl type monomer 1 having a carboxyl group or a phosphate group
And a hydrophobic polymer portion formed from 70 to 99% by weight of a lower alkyl (meth) acrylate copolymerizable with the vinyl-type monomer. Weight ratio of the hydrophilic polymer portion is 50 / 50-
A heat-curable antifogging composition for vehicle lighting, comprising a 95/5 block or graft copolymer. ## STR1 ## in _{CH 2 = CR 1 CONR 2 R} 3 above formula, R ₁ represents a hydrogen atom or a methyl group, R ₂ represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms, R ₃ Represents a hydrogen atom, a linear or branched alkyl group having 1 to 4 carbon atoms or an N, N-dimethylaminopropyl group. Embedded image In the above formula, R ₁ is a hydrogen atom or a methyl group, and A is-
_{(CH 2) 4 -, -} (CH 2) 5 - or - (CH _{2) 2}
-O- (CH _{2) 2} - represents a. 2. The block or graft copolymer,
The hydrophilic polymer portion is 1 to 15% by weight of N-methylol (meth) acrylamide, and at least one or more of N-substituted or unsubstituted (meth) acrylamide-based compounds represented by the above general formula 1 or 2 79% by weight, (meta)
At least one lower alkyl acrylate 15 to 5
The heating for a vehicle lighting device according to claim 1, wherein the heating is made of 0 wt% and at least one kind of lower alkoxyalkylene glycol (meth) acrylate represented by the following general formula 3 and 5 to 50 wt%. Curable antifoggant composition. CH ₂ = CR ₁ CO (OR ₂ ) n OR _{3 In the} above formula, R ₁ is a hydrogen atom or a methyl group, R ₂ is an ethylene group or a propylene group, R ₃ is a methyl group or an ethyl group, and n is Represents an integer of 1 to 23. 3. A heat-curable anti-fogging composition for vehicle lighting according to claim 1 or 2, wherein a surfactant is compounded, and the mixing ratio of the block or graft copolymer and the surfactant is a solid content weight. A heat curable antifogging composition for vehicle lighting, wherein the composition has a ratio of 100: 0.5 to 30. 4. A heat-curable anti-fogging composition for vehicle lighting according to claim 1, 2 or 3, which is applied to a base material, and the coating composition is coated with 70 to 145.
A vehicular lamp formed by heating and curing at a temperature of ° C to form an antifogging coating film on the surface.