JPH0575008B2 - - Google Patents

Description

[Detailed description of the invention]

"Industrial Application Field" The present invention relates to a vinyl chloride resin molded article.
More specifically, the present invention relates to a vinyl chloride resin molded product that prevents surface migration of plasticizers and the like and prevents contamination of the surface of the molded product. ``Prior Art'' Vinyl chloride resins are relatively inexpensive and difficult to undergo chemical changes, and their properties can be varied over a wide range from hard to soft by adding different amounts of plasticizer. Both hard and soft materials have many uses, such as hard pipes, flooring materials, sheets, films, soft vinyl cloth, fibers, wall materials, sheets, films, and daily necessities. However, over a long period of time in vinyl chloride resin molded products containing plasticizers, the plasticizer bleeds out onto the surface of the molded product and transfers to other substances.
It has the disadvantage of exhibiting undesirable phenomena such as being extracted by water or solvents. For example, if a soft vinyl chloride resin molded product comes into contact with the housing of an electrical product such as a television, video deck, or personal computer, which is made of styrene resin such as ABS resin, high-impact polystyrene, or general-use polystyrene, the housing may be exposed to plasticizer. Migrate. This migration can cause contamination spots and cracks on the housing, impairing its aesthetic appearance, significantly lowering its commercial value, and even lowering its functionality in some cases. In addition, if molded products made of vinyl chloride resin are used as flooring materials, interior materials such as wall materials, or outdoors such as tents, dust may accumulate on the plasticizer that bleeds out onto the surface of the molded product. It has the disadvantage of being contaminated due to adhesion. When the molded product is a film used for packaging, the bleed-out plasticizer reduces the printability of the film or reduces the strength of the parts bonded by heat sealing. As a method to solve these problems, a method has been proposed in which the surface of a vinyl chloride resin molded article is coated with a specific resin or paint. For example, special public service in 1977-
No. 29639, Japanese Patent Publication No. 50-28117, etc. propose a method of applying an acrylic resin to the surface of a vinyl chloride resin molded product. Furthermore, Tokko Akira
Publication No. 52-6214 proposes a method in which isocyanate or melamine resin is added as a crosslinking agent to a solvent solution of a vinyl monomer copolymer having a functional group, and the mixture is applied to a polyvinyl chloride film and partially crosslinked on the film. ing. However, since the coatings formed on the surfaces of molded products according to the improved method described above are mainly made of thermoplastic resin, if the ambient temperature is high during use or storage before use, It has the disadvantage that it is not sufficient to prevent plasticizers and the like from bleeding out onto the surface of the molded product, and the desired performance cannot be achieved. In order to improve these shortcomings, for example,
Japanese Patent No. 55-161826 proposes a method of forming a film derived from an epoxy resin composition that is polymerized by energy ray irradiation on the surface of a vinyl chloride resin molded article. Furthermore, JP-A No. 56-53070 discloses that a carboxylic acid derivative having an α,β-unsaturated group that can be cured by light or electron beam is coated on one or both sides of a polyvinyl chloride film. A method of forming a coating derived from a liquid is described. However, even with these improved methods, it is difficult to prevent plasticizer bleed out onto the surface of the molded product.
The reality is that this is not sufficient to prevent contamination of the molded product surface. "Problems to be Solved by the Invention" Under such circumstances, the present inventors have attempted to prevent the surface migration of various additives, especially plasticizers, blended into vinyl chloride resin molded products, and to improve the surface of the molded products. The present invention has been completed as a result of intensive studies aimed at providing a vinyl chloride resin molded product that prevents contamination. "Means for Solving the Problems" The above problems can be solved by using the vinyl chloride resin molded article according to the present invention. That is, the gist of the present invention is to coat the surface of a vinyl chloride resin molded article with a silane polymer having a hydrolyzable group directly bonded to a silicon atom or a hydrolyzate thereof mixed with a specific acrylic resin. The present invention relates to a vinyl chloride resin molded article, characterized in that it is formed with a coating derived from a composition. The present invention will be explained in detail below. In the present invention, the vinyl chloride resin includes not only polyvinyl chloride but also copolymers whose main component is vinyl chloride. Examples of monomer compounds copolymerizable with vinyl chloride include vinylidene chloride, ethylene, propylene, acrylonitrile, maleic acid, itaconic acid, acrylic acid, methacrylic acid, and vinyl acetate. These vinyl chloride resins may be produced by any of conventionally known production methods such as emulsion polymerization, suspension polymerization, solution polymerization, and bulk polymerization. In order to impart flexibility to the vinyl chloride resin that serves as the base, 100 parts by weight of this resin is added.
1 part by weight or more, preferably 20 to 60 parts by weight of plasticizer is blended. By controlling the blending amount of the plasticizer within the above range, it is possible to impart excellent flexibility and mechanical properties to the desired soft vinyl chloride molded product. Examples of the plasticizer include di-n-octyl phthalate, di-2-ethylhexyl phthalate,
Phthalic acid derivatives such as dibenzyl phthalate, diisodecyl phthalate, didodecyl phthalate, and diundecyl phthalate; Isophthalic acid derivatives such as dioctyl phthalate; Adipic acid derivatives such as di-n-butyl adipate and dioctyl adipate; Di-n-butyl maleate, etc. Maleic acid derivatives; citric acid derivatives such as tri-n-butyl citrate; itaconic acid derivatives such as monobutyl itaconate; oleic acid derivatives such as butyl oleate;
Ricinoleic acid derivatives such as glycerin monosinolate; other examples include phosphate ester plasticizers such as tricresyl phosphate and tricylenyl phosphate, epoxidized soybean oil, and epoxy resin plasticizers. In addition to the plasticizer, the vinyl chloride resin may contain, if necessary, known resin additives that are usually added to synthetic resins for molding, such as heat stabilizers, antioxidants, lubricants, and antistatic agents. Agents, surfactants, ultraviolet absorbers, light stabilizers, pigments, dyes, etc. can be blended. However, in order to formulate a vinyl chloride resin compound composition for molding by blending other known resin additives, including plasticizers, conventional blending and mixing techniques such as a ribbon blender, Banbury mixer, super mixer, etc. are used. A method using a blender or mixer can be adopted. There are no particular limitations on the shape of the soft vinyl chloride resin molded article of the present invention by molding the vinyl chloride resin blended composition. However, due to the ease of forming the coating, sheet-like, film-like,
A plate-like or tubular form is suitable.
These molding methods are appropriately selected from commonly used methods such as calendar molding, extrusion molding, inflation molding, and injection molding. Specifically, the silane polymer having a hydrolyzable group directly bonded to a silicon atom used in the present invention includes aminomethyltriethoxysilane, N-β-
aminoethylaminomethyltrimethoxysilane,
γ-aminopropyltrimethoxysilane, N-
Aminoalkylalkoxysilanes such as (trimethoxysilylpropyl)-ethylenediamine, N-(dimethoxymethylsilylpropyl)-ethylenediamine; γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β-(3, 4-epoxycyclohexyl)
Epoxyalkylalkoxysilane such as ethyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethylmethyldimethoxysilane; γ
-Mercaptopropyltrimethoxysilane, γ-
Mercaptoalkylalkoxysilanes such as mercaptopropylmethyldimethoxysilane; Tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, trimethoxyneopentoxysilane, dimethoxydineopentoxysilane; methyltrimethoxysilane, methyltrimethoxysilane; Alkyltrialkoxysilanes such as ethoxysilane, ethyltrimethoxysilane and ethyltriethoxysilane; Dialkylalkoxysilanes such as dimethyldimethoxysilane and dimethyldiethoxysilane; γ-chloropropyltrimethoxysilane, 3,3,3-trichloropropyltrisilane, etc. Halogenated alkyl alkoxysilanes such as methoxysilane; Alkylaciloxysilanes such as methyltriacetoxysilane and dimethyldiacetoxysilane; hydrosilane compounds such as trimethoxysilane and triethoxysilane; vinyltrimethoxysilane, vinylethoxysilane, vinyltris(β -Unsaturation such as methoxyethoxy)silane, allyltriethoxysilane, γ-(meth)acryloxypropyltrimethoxysilane, γ-(meth)acryloxypropyltriethoxysilane, γ-(meth)acryloxypropylmethyldimethoxysilane, etc. Examples include polymers of group-containing silane compounds. In the present invention, a hydrolyzate can further be used. The hydrolyzate is synthesized, for example, by adding water to a silane polymer having a hydrolyzable group in the presence of an acid or alkali catalyst in the presence of an alcohol-containing silane polymer. When more than an equivalent amount of water is added to the polymer, completely hydrolyzed alcoholic silica gel or silica sol, or a siloxane-based composite is obtained; if less than an equivalent amount of water is added, hydration is performed according to the ratio. A decomposition product is prepared. Among these silane polymers having a hydrolyzable group directly bonded to a silicon atom, tetraalkoxysilane polymers or hydrolysates thereof are particularly preferred. Moreover, these may be used together. In the present invention, the acrylic resin refers to 5 to 40% by weight of hydroxyalkyl (meth)acrylate,
A polymer obtained by copolymerizing 0 to 20% by weight of an α,β-unsaturated carboxylic acid containing one or more carboxyl groups in the molecule and another vinyl compound that can be copolymerized with these compounds. means. The term hydroxyalkyl (meth)acrylate as used herein means hydroxyalkyl acrylate or hydroxyalkyl methacrylate. Hydroxyalkyl (meth)acrylates include hydroxymethyl acrylate, hydroxymethyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate,
2-hydroxypropyl methacrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, 4-
Examples include hydroxybutyl methacrylate, 2-hydroxypentyl acrylate, 2-hydroxypentyl methacrylate, 6-hydroxyhexyl acrylate, and 6-hydroxyhexyl methacrylate. The proportion of this hydroxyalkyl (meth)acrylate in the acrylic resin is 5% by weight.
If the amount is less, it is not preferable because the solubility with the organic solvent, the adhesion with the base molded article, and the effect of inhibiting plasticizer migration cannot be sufficiently exhibited. On the other hand, 40% by weight
If the amount is larger than that, the cost will increase and the effect obtained will not be large compared to the increase in cost, which is not preferable. Examples of α,β-unsaturated carboxylic acid compounds containing one or more carboxyl groups in the molecule include acrylic acid, methacrylic acid, itaconic acid, maleic acid, aconitic acid, and crotonic acid. When these compounds are used in combination with the hydroxyalkyl (meth)acrylates, the adhesion between the coating composition, which is a mixture of the acrylic resin and the silane compound, and the vinyl chloride resin base film is improved, and the films adhere to each other ( It exhibits the effect of suppressing the blocking property. The amount of these compounds used is up to 20% by weight. If it is more than this, the property of films adhering to each other when they leak moisture (blocking property when wet) is strengthened, which is not preferable. Other vinyl compounds that can be copolymerized with the above compounds that make up the remainder include methyl acrylate,
Acrylic acids such as ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, decyl acrylate, dodecyl acrylate, tridecyl acrylate, stearyl acrylate, etc. C1- _C22 alkyl esters: methyl methacrylate, ethyl methacrylate, n _- propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate,
C1- _C22 alkyl esters of methacrylic acid such as cyclohexyl methacrylate, 2 _- ethylhexyl methacrylate, decyl methacrylate, dodecyl methacrylate, tridecyl methacrylate, stearyl methacrylate, etc.: styrene, acrylonitrile, methacrylonitrile, vinyl acetate, propionic acid Examples include vinyl, acrylamide, methacrylamide, n-butoxyacrylamide, n-butoxymethacrylamide, and the like. Acrylic resin is prepared by combining a predetermined amount of two or more of the above monomers together with an organic solvent into a polymerization can, adding a polymerization initiator and, if necessary, a molecular weight regulator, and heating while stirring to polymerize. do. In this case, examples of polymerization initiators that can be used include radical-generating catalysts such as α,α-azobisisobutyronitrile, benzoyl peroxide, and cumene hydroperoxide, and examples of molecular weight regulators include butyl mercaptan and n- dodecyl mercaptan,
Examples include tert-dodecylmercaptan and β-mercaptoethanol. Organic solvents used for polymerization include methanol,
Ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-
Alcohols such as butanol, n-amyl alcohol, isoamyl alcohol, tert-amyl alcohol, n-hexyl alcohol, and cyclohexanol; Aromatic hydrocarbons such as benzene, toluene, and xylene; Acetic esters such as ethyl acetate and butyl acetate Ketones such as acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, diethyl ketone, 2-hexanone, 3-hexanone, di-n-propyl ketone, diisopropyl ketone, di-n-amyl ketone, cyclohexanone; tetrahydrofuran These can be used alone or in combination of two or more. The mixing ratio of the above silane polymer and acrylic resin is 1 to 90 for the former and 99 to 10 for the latter in terms of solid content weight ratio.
(The total amount of both is 100.) The ratio is particularly preferably 5 to 80 to 95 to 20. If the blending ratio of the former is less than this, the effect of preventing migration of plasticizers etc. and stain resistance of the formed film will not be sufficient, and conversely, if it is more than this, the formed film will tend to be sticky, which is preferable. do not have. The above-mentioned coating composition can be used by dissolving it in an organic solvent. Examples of organic solvents include methanol, ethanol,
Alcohols such as isopropyl alcohol, aliphatic hydrocarbons such as heptane and cyclohexane, aromatic hydrocarbons such as benzene, toluene and xylene, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ethyl acetate and acetic acid n
- Acetate esters such as butyl alone or in combination
Can be used in combination with more than one species. In addition to these components, the coating composition may contain auxiliary components such as antioxidants, neutralizers, ultraviolet absorbers, light stabilizers, antistatic agents, pigments, dyes, and lubricants. can. In order to apply the above-mentioned coating composition to form a film on the surface of a vinyl chloride resin molded article, various known methods can be applied depending on the shape of the molded article. For example, when forming a film in a solution state, coating methods such as doctor blade coating method, gravure roll coating method, air knife coating method, reverse roll coating method, dip coating method, curtain roll coating method, spray coating method, rod coating method, etc. is used.
In addition, when the coating composition is formed as a single film without being in a solution state, a coextrusion method, an extrusion coating method, an extrusion lamination method, and a lamination method are used. When a coating method is used as a film forming method, there are, for example, natural drying methods, hot air drying methods, infrared drying methods, far infrared drying methods, etc., but if drying speed and safety are taken into account, Hot air drying methods are advantageous. In this case, the temperature condition should be in the range of 50 to 150°C, and the time should be selected in the range of 10 seconds to 15 minutes. When applying the above-mentioned coating composition to the surface of a vinyl chloride resin molded article to form a film, the coating amount is 0.1 g/m ² to 10 after drying and solidification, depending on the coating method.
A range of g/m ² is preferred. If it is less than 0.1 g/m ² , the effect of preventing the plasticizer from migrating to the surface of the vinyl chloride resin molded product is insufficient. In addition, if it is 10 g/m ² or more, the amount of coating is too large,
This is economically disadvantageous, and especially when the vinyl chloride resin molded article to be coated is a film-like structure, its mechanical strength may decrease. Therefore, a range of 0.5 g/m ² to 5 g/m ² is usually most preferred. In addition, before coating with the above-mentioned coating composition, the surface of the vinyl chloride resin molded product is washed with alcohol or water, subjected to plasma discharge treatment or corona discharge treatment, or undercoated with other paint or primer. Pretreatment such as the following may be performed. "Effects of the Invention" and "Actions" The vinyl chloride resin molded product according to the present invention has a specific coating formed on its surface, and this coating can be used for various resin additives such as plasticizers blended into the molded product. It has excellent stain resistance because it prevents oozing out. Therefore, the vinyl chloride resin molded product of the present invention can maintain a beautiful appearance for a long time, and can be used in various fields such as electrical appliances, interior materials, agricultural materials, etc., and has great industrial value. "Examples" Hereinafter, the present invention will be explained in detail based on Examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. Examples 1 to 6, Comparative Examples 1 to 3 Preparation of base film Polyvinyl chloride (=1400) 100 parts by weight Dioctyl phthalate 50 Epoxidized soybean oil 3 Barium-zinc composite liquid stabilizer 1.5 Barium stearate 0.2 A resin composition consisting of 0.4 mm of zinc stearate was prepared, mixed for 10 minutes using a super mixer, and then kneaded on a mill roll heated to 180°C to prepare a soft vinyl chloride resin film with a thickness of 0.3 mm. did. Preparation of acrylic resin A: In a reactor equipped with a thermometer, stirrer, reflux condenser, and charging nozzle, add 15 parts by weight of 2-hydroxyethyl methacrylate, 5 parts by weight of acrylic acid, 45 parts by weight of methyl methacrylate, and n-butyl acrylate. 35 parts by weight, 1 part by weight of benzoyl peroxide, and 200 parts by weight of methyl ethyl ketone were added, and while stirring in a nitrogen gas stream,
The mixture was reacted at ℃ for 7 hours to obtain an acrylic resin solution. This is called acrylic resin (A). B Into the same reactor used in the example described in section A, 10 parts by weight of 2-hydroxyethyl methacrylate, 3 parts by weight of methacrylic acid, 60 parts by weight of methyl methacrylate, 27 parts by weight of butyl methacrylate, 1 part by weight of benzoyl peroxide. , 200 parts by weight of methyl ethyl ketone were charged and reacted in the same manner as described in Section A to obtain an acrylic resin solution. This is called acrylic resin (B). C Into the same reactor used in the example described in Section A, 55 parts by weight of methyl methacrylate, 40 parts by weight of butyl methacrylate, 5 parts by weight of butyl acrylate, 1 part by weight of benzoyl peroxide, and 200 parts by weight of methyl ethyl ketone were charged. The reaction was carried out in the same manner as described in , to obtain an acrylic resin solution. This is called acrylic resin (C). Formation of a film: Blend the silane polymer and acrylic resin in the type and amount shown in Table 1, add isopropyl alcohol to the solid content so that the solid content is 20% by weight,
A coating composition was obtained. However, in Comparative Example 2, no silane polymer was blended. Furthermore, in Comparative Example 3, no acrylic resin was blended. On one side of the base film prepared by the above method,
The above coating composition was applied using a #5 bar coater,
Each was applied. The coated film was kept in an oven at 130° C. for 1 minute to volatilize the solvent. The amount of coating on each film obtained was approximately 3 g/m ² . However, in Comparative Example 1, no film was formed. Evaluation of the film The performance of the film was evaluated using the following methods.
The results are shown in Table 1. Contamination resistance Each contaminant is attached to the coating surface of the film,
After leaving it at room temperature for 48 hours, the contaminants were wiped off with absorbent cotton and the traces were observed. This evaluation criteria is
It is as follows. ◎…No traces found at all. 〇… Traces are observed on a part of the coating. △… Traces are observed on more than 2/3 of the coating. ×... Traces are observed on the entire surface of the coating. Plasticizer Migration Test Nine types of films were each cut into 10 cm x 10 cm squares, and a 0.5 mm thick polystyrene sheet was adhered to the surface on which the film was formed. In this state, 2
In an oven maintained at 50℃ with a load of kg,
It was left for 48 hours. The film was then removed from the oven, the load was removed, the polystyrene sheet was peeled off, and the weight loss of each of the nine types of films was measured. The lower the value, the less the plasticizer migrates from the film surface. Peelability (Tackiness) Nine types of films were each cut into pieces of 5 cm wide and 20 cm long, and folded back alternately at 5 cm intervals in a direction perpendicular to the long direction. In this state, a load of 2 kg was applied from above and the product was left in an oven maintained at 50° C. for 1 hour. Then, the film was taken out from the oven, the load was removed, and the film was peeled off, and the peelability at that time was observed. The evaluation criteria are as follows. ◎…It has no resistance at all and can be easily peeled off. △...There is some resistance. ×: Something that is extremely resistant and requires force to peel off.

【table】

[Table] From Table 1, the vinyl chloride resin molded product according to the present invention has particularly excellent plasticizer migration resistance and stain resistance, so it can prevent contamination, dust, dirt, etc. from adhering to the surface of the molded product. It can be seen that it is possible to maintain a beautiful appearance for a long period of time.

Claims (1)

[Scope of Claims] 1. A silane polymer having a hydrolyzable group directly bonded to a silicon atom or a hydrolyzate thereof is applied to the surface of a vinyl chloride resin molded product, and 5 to 40% by weight of the silane polymer has a hydroxyalkyl (meth)acrylate monomer. , 0~
By copolymerizing a monomer component in which 20% by weight is an α,β-unsaturated carboxylic acid containing one or more carboxyl groups in the molecule, and the remainder is another vinyl compound that can be copolymerized with these compounds. A vinyl chloride resin molded article, characterized in that a coating derived from a coating composition mixed with the obtained acrylic resin is formed. 2. The vinyl chloride resin molded article according to claim 1, wherein the silane polymer having a hydrolyzable group directly bonded to a silicon atom is a polymer of tetraalkoxysilane.