JP2005075958A - Adhesive for flocking and flocked product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solvent-type adhesive for flocking on a vinyl acetate resin for producing a flocked product by using a vinyl acetate resin having excellent safety and recyclability as a flocking substrate and provide a flocked product produced by bonding with the adhesive. <P>SOLUTION: A flocked product having durability, excellent recyclability and biological safety and high drying speed and adhesive force is produced by a uniform and high-quality flocking treatment on a surface of a vinyl acetate resin substrate unsuitable for flocking by conventional method. The flocked product is produced by an electrostatic flocking technique using a flocking adhesive composed of an ethylene-vinyl acetate copolymer resin (EVA), a brominated aromatic hydrocarbon resin, a 7-8C aromatic hydrocarbon and cyclohexanone or an acetic acid ester compound. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a flocking adhesive for flocking a pile onto a vinyl acetate resin excellent in safety to a living body, and a flocking product obtained by flocking a pile using the flocking adhesive.

In the soft vinyl industry, there are character goods, toys such as Christmas boots, and the surface of ornaments in which rayon fibers or nylon fibers are flocked.
In the prior art, synthetic resins such as foamed polystyrene and vinyl chloride (PVC) resin are used for the planted base material.

  Most of the flocking process to a synthetic resin base material is performed using an adhesive diluted with a commercially available water-soluble emulsion type bond. For example, Patent Document 1 discloses an electrostatic flocking adhesive for vinyl chloride obtained by adding an epoxy-modified acrylic emulsion and a polyisocyanate curing agent to an ethylene-vinyl acetate copolymer (EVA) emulsion.

  Most of toy and decorative products are styrofoam flocked products using water-soluble emulsion type vinyl acetate adhesive. Generally, a water-soluble emulsion type vinyl acetate adhesive is diluted with water and used as an adhesive for electrostatic flocking.

JP-A-6-1960

  In products and the like planted on a grafted substrate of vinyl chloride resin (PVC) using a water-soluble emulsion type vinyl acetate adhesive as disclosed in Patent Document 1, since it is chlorine-based, it is safe for the living body. There is a problem that environmental load is large, such as dioxin is generated at the time of incineration disposal.

  In order to solve such problems as safety, it is considered optimal to select a vinyl acetate resin as the base material to be implanted, but the following problems are associated with water-soluble emulsion type vinyl acetate adhesives: Furthermore, the water-soluble emulsion type vinyl acetate adhesive does not have an adhesive force to vinyl acetate.

  Styrofoam flocked products using a water-soluble emulsion type vinyl acetate adhesive cannot be stored for a long period of time due to lack of water resistance. In addition, once used, damage remains on the flocked surface of the flocked product, causing deterioration. Accordingly, there are many production restrictions for conventional products, such as Christmas decorations, because they are not suitable for storage as inventory until next season.

  Furthermore, when a water-soluble emulsion type vinyl acetate adhesive is diluted and used as an adhesive for electrostatic flocking, it is difficult to adjust the viscosity and yield value (thixotropic properties). When the viscosity and the yield value are high, the film thickness of the coating film becomes non-uniform, and the portion where the adhesive is thinly applied has a poor flocking condition, while the thick portion is piled in the adhesive. In addition, when the rubber viscoelasticity is low and the diluted state of the adhesive is thin, the bonded portion between the pile and the adhesive is reduced, and the flocking strength is reduced. Furthermore, since the synthetic fiber pile used for flocking is water repellent, the surface tension applied between the pile and the water-soluble adhesive is increased, and therefore the bonded portion between the pile and the adhesive after drying is reduced, resulting in durability. Has the disadvantage of weakening.

  The present invention provides a solvent-based flocking adhesive for resin for obtaining a flocked product using a vinyl acetate resin excellent in safety and recyclability as a planted base material, and a flocked product bonded using the same. For the purpose.

  The flocking adhesive of the present invention contains an ethylene-vinyl acetate copolymer resin, a brominated aromatic hydrocarbon resin, an aromatic hydrocarbon having 7 or 8 carbon atoms, and cyclohexanone or an acetate ester compound. And

  The flocked product of the present invention contains an ethylene-vinyl acetate copolymer resin (EVA), a brominated aromatic hydrocarbon resin, an aromatic hydrocarbon having 7 or 8 carbon atoms, and cyclohexanone or an acetate ester compound. Using an adhesive, the pile can be obtained by flocking onto a base material made of vinyl acetate resin. An electrostatic flocking method is used for flocking.

  As a result of intensive studies to achieve the above object, it was found that the composition of the present invention, which is solvent-based, is very suitable for flocking adhesives for vinyl acetate resins. When producing an adhesive composition for flocking containing an ethylene-vinyl acetate copolymer resin (EVA), a brominated aromatic hydrocarbon resin, and a solvent, toluene and cyclohexanone or an acetate ester compound are used as the solvent. As a result, the inventors have obtained the knowledge that a high performance adhesive composition for electrostatic flocking using a vinyl acetate resin substrate as an application, and have reached the present invention.

  Aromatic hydrocarbons such as toluene are highly compatible with ethylene-vinyl acetate copolymer resin (EVA) and brominated aromatic hydrocarbon resins, and have low volatility compared to other adhesive solvents. Sometimes drying only from the surface can be prevented. Moreover, since aromatic hydrocarbon is lipophilic, the surface tension with respect to a pile is small, and it can fully contact an adhesive agent component with a pile.

  Furthermore, by using cyclohexanone (boiling point 157 ° C.) and toluene (boiling point 110 ° C.) in combination, the drying rate from the surface of the adhesive coating can be slowed, and the internal residual solvent can be more effectively prevented.

  The acetate compound is highly compatible with the ethylene-vinyl acetate copolymer (EVA) resin and the aromatic hydrocarbon, and can effectively prevent the residual solvent inside the adhesive.

  By mixing two or more types of ethylene-vinyl acetate copolymer (EVA) resins having different densities, the viscosity is stabilized, rubber viscoelasticity is improved, and weather resistance (cold resistance) is improved.

  The brominated aromatic hydrocarbon resin has a high effect as a paint, has an effect of improving the coating film strength and high drying property, and promoting drying from the inside of the coating film. In addition, since it is excellent in acid resistance, alkali resistance, and water resistance, it is possible to stabilize the quality of the product over a long period of time.

  By using the flocking adhesive obtained in the present invention, a pile can be flocked to a vinyl acetate resin, and a flocked product can be produced.

According to the present invention, the following effects can be obtained.
(1) A flocking product using a vinyl acetate resin as a flocked base material can be provided with higher adhesive strength and higher durability than conventional products. Thereby, the use to the toy of the flocked product using the vinyl acetate resin excellent in safety | security, a decorative article, etc. expands.

(2) Since the brominated aromatic hydrocarbon resin is excellent in acid resistance, alkali resistance and water resistance, the long-term stability of the quality of the flocked product is improved.

(3) Since the solvent-type vinyl acetate-based adhesive has a faster drying speed than the conventional water-soluble emulsion-type vinyl acetate-based adhesive, the processing speed and productivity of the flocked product are improved.

(4) Cyclohexanone can prevent the residual solvent inside the adhesive more effectively by preventing drying from the surface of the adhesive coating. The acetate compound is highly compatible with ethylene-vinyl acetate copolymer (EVA) resin, and can effectively prevent residual solvent inside the adhesive.

(5) By using raw materials of the same type as molded products, processing bonds, and flocked fibers as adhesives, flocked products are crushed without being separated after use and recycled as raw material thickeners (reuse). Is possible.

Hereinafter, it demonstrates in detail based on embodiment of this invention.
First, the adhesive used for flocking will be described.

  The vinyl acetate content of the ethylene-vinyl acetate copolymer resin (EVA) (hereinafter referred to as component (A)) used in the present invention is preferably 15 to 40%, more preferably 15 to 35%. Yes, most preferably 30%. If it is less than 15%, the adhesive strength as an adhesive is too low, and if it exceeds 40%, the rigidity of the adhesive is impaired. These may use one kind of resin selected from the above range, but two or more kinds of resins having a high vinyl acetate content (high density) and resins having a low vinyl acetate content (low density) are used. It is preferable to use together in arbitrary ratios. It is because rubber viscoelasticity will improve and a weather resistance (cold resistance) will be improved when two or more types are used together.

  The brominated aromatic hydrocarbon resin (hereinafter referred to as component (B)) used in the present invention is an aromatic hydrocarbon resin containing bromine. An aromatic hydrocarbon having a bromine number of 15 to 30 is more preferable, and a bromine number of 20 to 25 is most preferable. This is because when the bromine number is less than 5, the effect of maintaining the hardness of the coating film is lost, and when the bromine number exceeds 40, the rigidity of the polymer becomes too high. The softening point of the resin is preferably 90 to 150 ° C, and optimally 125 to 140 ° C. These may be used alone or in combination of two or more.

  The aromatic hydrocarbon having 7 or 8 carbon atoms (hereinafter referred to as component (C)) used in the present invention is preferably toluene, o-xylene, m-xylene, p-xylene, ethylbenzene or styrene. More preferably, toluene, o-xylene, m-xylene, and p-xylene. Most preferred is toluene. These may be used alone or in combination of two or more.

  The cyclohexanone or acetate compound (hereinafter referred to as component (D)) used in the present invention is preferably cyclohexanone, or ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, sec-butyl acetate. Acetate compounds such as tert-butyl acetate, isobutyl acetate and vinyl acetate. Most preferred is cyclohexanone. These may be used alone or in combination of two or more.

  As described above, the additive to the adhesive composition is not limited to the above, and optional components other than the above composition, thickener, filler, antioxidant, ultraviolet absorber, dye, pigment as necessary Etc. can be used together. For example, the adhesive itself can be colored by mixing solvent type ink.

  Speaking of the usage ratio of each component in obtaining the adhesive of the present invention, the resin component (B) is usually 0.56 to 0.77 parts by weight, preferably 1 part by weight of the resin component (A). Is used in a ratio ranging from 0.6 to 0.73 parts by weight, more preferably from 0.64 to 0.68 parts by weight. If the ratio of the component (B) is less than 0.56 of the component (A), the hardness of the coating film cannot be maintained, and if it exceeds 0.77, the vinyl acetate ratio decreases and the adhesive strength decreases. A solvent adds a component (D) with respect to a component (C) normally in 1-14 weight part, Preferably it is 3-10 weight part, More preferably, it is 5-8 weight part, and makes it a total of 100 weight part. Used in ratio. The resin with the above ratio is usually added in the range of 10 to 35 parts by weight, preferably 15 to 30 parts by weight with respect to the solvent with the above ratio, and is used in a ratio of 100 parts by weight in total.

  The method for preparing the adhesive of the present invention will be described. A constant temperature stirring tank is used for the preparation. The component (C) and the component (D) in the above ratio are put into a stirring tank. While maintaining the temperature of the tank at 45 to 60 ° C., preferably 50 to 60 ° C., 10 to 35 parts by weight, preferably 15 to 30 parts by weight of component (A) and component (B) are added, and a total of 100 parts by weight. And stirring so as not to cause poor stirring. This is because if the temperature of the tank is lower than 45 ° C., the solubility of the resin in the solvent decreases and it takes time to mix, and if it exceeds 60 ° C., part of the solvent volatilizes during long-time stirring. If the above ranges of the resin components (A) and (B) are less than 10 parts by weight, the viscosity is too low to be suitable for flocking, and if it exceeds 35 parts by weight, the viscosity is too high to be suitable for flocking. Although there is no special limitation in mixing time, 3 hours or more are preferable. After confirming that the raw materials are sufficiently mixed, the mixture is cooled to room temperature to obtain an adhesive.

Next, the material and method used for flocking will be described.
The pile fiber used in the present invention preferably has a fineness of 0.1 to 7 denier and a fiber length of 0.1 to 2.5 mm. If the thickness exceeds 7 denier, the flight performance of the pile at the time of electrostatic flocking deteriorates. If the fiber length is less than 0.1 mm, the pile is buried in the adhesive, and if it exceeds 2.5 mm, the flight performance deteriorates. Examples of the pile material include rayon and nylon, and rayon is most suitable. The pile may have any shape. The pile is most preferably planted perpendicular to the adhesive layer, but may be planted obliquely.

  The vinyl acetate resin of the to-be-grafted base material of the flocked product used in the present invention is an ethylene-vinyl acetate copolymer (EVA) resin. The to-be-grafted base material should just be ethylene-vinyl acetate copolymer resin (EVA) as a main raw material, does not prevent addition of other components, such as a plasticizer and an additive, and the ratio is not ask | required. The thickness, size, and shape of the substrate are not particularly limited, and are appropriately selected depending on the purpose, application, and production conditions.

  The method for applying the adhesive to the substrate to be transplanted is preferably mechanical application that allows uniform application, but is not particularly limited.

  The hair transplantation method in the present invention is most preferably an electrostatic hair transplantation method using a high-voltage direct current electrostatic field. The intensity of the DC electrostatic field is set in the range of 12 to 25 kV depending on the humidity in the air. Moreover, the electrostatic flocking method of the present invention includes a vacuum deposition method in which flocking is performed using an electrostatic field under a high reduced pressure.

  In order to describe the present invention more specifically, examples and comparative examples will be described below, but the present invention is not limited to these examples. In the following, unless otherwise specified, parts are parts by weight and% is based on weight%.

[Example 1]
A thermostatic stirring tank was used for the preparation. As shown in Table 1, 75.2 parts of toluene and 3.6 parts of cyclohexanone were charged into a stirring tank, and 9.2 parts of ethylene-vinyl acetate copolymer resin (EVA) 32% was maintained while maintaining the stirring tank at 55 ° C. After adding 3.6 parts of ethylene-vinyl acetate copolymer resin (EVA) 28% and 7 parts of brominated aromatic hydrocarbon resin (bromine number 20) in small amounts so as not to cause poor stirring. Stirring was performed for 3 hours. After confirming that the raw materials were sufficiently mixed, the mixture was cooled to room temperature to obtain an adhesive. The obtained adhesive with a viscosity of 300 cps was uniformly applied to a molded article of vinyl acetate resin (vinyl acetate concentration 20%) that would be a base material to be implanted at a temperature of 30 ° C. The iron core used as the cathode of an electrostatic flocking apparatus was attached to the vinyl acetate resin of the to-be-planted base material, and it attached in parallel with the position of about 10 cm on the anode. A flat electrode plate serving as an anode was covered with a pile made of rayon (fineness 1.5 denier, fiber length 0.4 mm) as a flocking material. A DC voltage of 20 kV was applied between the cathode-side substrate and the anode flat electrode plate for 1 minute using a static electricity generator (manufactured by Nihon Pile), and the piles were scattered and planted. Then, it was dried at 30 ° C. for 24 hours.

[Comparative Example 1]
1 part of a commercially available water-soluble emulsion type vinyl acetate adhesive (41% vinyl acetate resin emulsion component, 59% water; Konishi Co., Ltd. # 35914) diluted with 1 part of water to obtain an adhesive having a viscosity of 500 cps Was applied to a molded article of a vinyl acetate resin (vinyl acetate concentration 20%) to be a grafted substrate at an air temperature of 30 ° C. Although flocking was carried out by the same method as in Example 1, after drying, the adhesive peeled off from the surface of the to-be-grafted substrate, and was unsuitable for the use of vinyl acetate resin.

[Comparative Example 2]
1 part of a commercially available water-soluble emulsion type vinyl acetate adhesive (41% vinyl acetate resin emulsion component, 59% water; Konishi Co., Ltd. # 35914) diluted with 1 part of water to obtain an adhesive having a viscosity of 500 cps Was applied to a molded product of a foamed polystyrene resin to be a base material to be implanted at a temperature of 30 ° C. The flocking was carried out by the same method as in Example 1. Then, it was dried at 30 ° C. for 24 hours.

注１）水溶性エマルジョン型酢酸ビニル系接着剤（酢酸ビニル樹脂エマルジョン成分４１％、水５９％；コニシ株式会社製＃３５９１４）
注２）剥離試験
酢酸ビニル樹脂基材表面に接着剤をスポイドで１０ｃｍの高さより１滴滴下し、気温３０℃の中、２４時間放置した後、市販のセロファンテープを貼り約５分後に剥がした。
○：剥がれない
×：全面剥がれる
注３）植毛強度試験１
植毛加工品の表面に市販のセロファンテープを貼り、その上を１０回、１ｋｇ重の圧力をかけながら摩擦した後、セロファンテープを剥がす。
○：変化無し
×：植毛がほとんどとれる
注４）植毛強度試験２
綿製のブロード布を用い、１ｋｇ重の荷重で表面を３０回擦った後に表面を観察する。
○：変化無し。パイルが揃って若干艶が出る。
×：植毛が薄くなり、基材が見える。

Note 1) Water-soluble emulsion type vinyl acetate adhesive (vinyl acetate resin emulsion component 41%, water 59%; Konishi Co., Ltd. # 35914)
Note 2) Peel test One drop of adhesive was dropped from the height of 10 cm on the surface of the vinyl acetate resin substrate, left at a temperature of 30 ° C for 24 hours, and then a commercially available cellophane tape was applied and peeled off after about 5 minutes. .
○: not peeled ×: peeled all over Note 3) Flocking strength test 1
A commercially available cellophane tape is affixed to the surface of the processed flocked product, and the cellophane tape is peeled off after being rubbed 10 times while applying a pressure of 1 kg.
○: No change ×: Most of the planting can be removed Note 4) Planting strength test 2
Using a cotton broad cloth, the surface is observed after being rubbed 30 times under a load of 1 kg.
○: No change. The piles are aligned and slightly glossy.
X: The hair transplantation becomes thin and the substrate can be seen.

  The present invention is an invention relating to a flocking adhesive, and a flocking technique using this adhesive on a vinyl acetate resin surface, which has not been suitable for flocking in the past, provides high adhesion, durability, processing speed and productivity. Excellent, uniform and high-quality, safe flocking products suitable for recycling can be manufactured.

Claims (5)

  A flocking adhesive comprising an ethylene-vinyl acetate copolymer resin, a brominated aromatic hydrocarbon resin, an aromatic hydrocarbon having 7 or 8 carbon atoms, and cyclohexanone.   An adhesive for flocking containing an ethylene-vinyl acetate copolymer resin, a brominated aromatic hydrocarbon resin, an aromatic hydrocarbon having 7 or 8 carbon atoms, and an acetate ester compound.   A pile is formed on a base material made of vinyl acetate resin using an adhesive containing ethylene-vinyl acetate copolymer resin, brominated aromatic hydrocarbon resin, aromatic hydrocarbon having 7 or 8 carbon atoms, and cyclohexanone. Flocked products that have been flocked.   Using an adhesive containing an ethylene-vinyl acetate copolymer resin, a brominated aromatic hydrocarbon resin, an aromatic hydrocarbon having 7 or 8 carbon atoms, and an acetate ester compound on a base material made of vinyl acetate resin A flocking product made from a pile.   The flocked product according to claim 3 or 4, wherein the pile is flocked by an electrostatic flocking method.