JP3034064B2 - Adhesive for electrostatic flocking - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a method for producing a polypropylene sheet or a molded product thereof by applying polyester,
The present invention relates to an aqueous emulsion type adhesive used for bonding short fibers such as nylon and polyester-acryl.

[0002]

2. Description of the Related Art In recent years, automobile interior materials have been reduced in weight, moldability,
Due to cost reduction and the like, polypropylene resin has been actively used. Conventionally, molded articles made of ABS or polypropylene resin have been used as members for automobile interior materials as they are. However, due to the sophistication, aesthetics, and design of automobiles, the number of cases where such surfaces are subjected to electrostatic flocking is increasing. As we all know,
Since non-polar polypropylene is a hardly adherent material, research has been conducted to provide not only adhesives for electrostatic flocking but also adhesives for polyolefins to impart adhesion or adhesion to polypropylene.

For example, Japanese Patent Application Laid-Open No. 1-108286 discloses a method in which a mixture of chloroprene rubber and a tackifying resin is used as a main component, and hydrogenated polybutadiene glycol is used as a curing agent, which is terminally isocyanated with a polyisocyanate compound. According to Kaihei 1-153787,
A method using chloroprene rubber and atactic polypropylene as main components and using chloroprene rubber and tertiary butyl phenol as curing agents. Japanese Unexamined Patent Publication No. Hei. JP-A-2-
In 218778, a modified polyolefin obtained by graft-modifying a polyolefin having an α-olefin having 3 to 4 carbon atoms as a main constituent unit and having an intrinsic viscosity of 1 dl / g or more with an unsaturated dicarboxylic acid or an anhydride thereof is further used. In the chlorinated product described in JP-A-1-174579, the content of the propylene unit (a) is 15 to 90 mol%,
The content of α-olefin units (b) is from 10 to 85
Mol% [the total content of (a) and (b) is 100 mol%], and the intrinsic viscosity [η] measured in decalin at 135 ° C. is in the range of 0.5 to 5.0 dl / g. A chlorinated olefin polymer having a chlorine content of 5 to 8
Solvent-type or aqueous emulsion-type adhesives such as water-dispersed adhesives containing an aqueous dispersion containing a chlorinated olefin polymer in a range of 0% by weight in a solid content concentration of 5 to 30% by weight as an active ingredient. Proposed.

[0004]

As described above, polypropylene is a plastic which is difficult to adhere to. Therefore, in order to improve the adhesiveness of polypropylene itself, it is modified by adding a filler such as talc, calcium carbonate, wood flour, or the like. Alternatively, the anhydride is modified by grafting, but it is imperfect from the viewpoint of adhesiveness, and its surface is usually subjected to a primer treatment, which is leading to cost improvement. On the other hand, with respect to the problem of the adhesive, the two-component mixing type comprising the main agent and the curing agent has problems such as workability, mixing errors, and limitations on the pot life after mixing the two components. Further, in the case of the solvent type adhesive, there is an extremely high risk of environmental pollution by organic solvents, adverse effects on human bodies, fires, explosions and the like. As a method for solving such a problem, the development of a one-pack type aqueous emulsion has been promoted, but any of the proposals uses an expensive organic solvent dilution of chlorinated polypropylene or chlorinated modified polypropylene, Emulsification and further steps such as desolvation are required, resulting in an extremely expensive adhesive and lacking industrial practicality.

[0005]

Means for Solving the Problems In the electrostatic flocking of a polypropylene base, the present inventors have found that while being an aqueous emulsion, it does not have to be treated with a primer, has adhesiveness to polypropylene, and has an electrostatic property. As a result of intensive studies to delay the pot life before flocking, butyl carbitol, which suppresses drying or emulsion film formation, was added to the acrylic emulsion, and further, adhesion was provided for the purpose of improving the adhesion to polypropylene. It has been found that the combined use of synthetic rubber latex is extremely effective as an adhesive for electrostatic flocking of a polypropylene base material, and the present invention has been completed.

That is, according to the present invention, (1) 1 to 30 parts by weight of butyl carbitol and 10 to 300 parts by weight of a tackified synthetic rubber latex as solids are blended with respect to 100 parts by weight of solids of an acrylic emulsion. Adhesive for flocking. (2) The above-mentioned (1), wherein the tackified synthetic rubber latex synthesizes 10 to 50 parts by weight of a tackifying resin in 100 parts by weight of the solid content of the synthetic rubber latex.
Is an adhesive for electrostatic flocking. The acrylic emulsion used in the present invention has a glass transition temperature (Tg) usually used as an adhesive of −30 to 20 ° C. and an average particle diameter of 0.1.
0.3 micron, solid content 30-65%, viscosity 50-5
000 cps, pH 6-9, and there is no particular limitation. For example, a copolymer emulsion selected from the group consisting of a hard monomer, a soft monomer, and a functional group monomer as described below is suitable.

Specifically, examples of the hard monomer include one or more selected from the group consisting of styrene, methyl methacrylate, acrylonitrile, vinyl acetate and the like. As the soft monomer, methyl acrylate, ethyl acrylate, butyl acrylate,
One or more selected from the group of 2-ethylhexyl acrylate and the like can be mentioned. As the functional group monomer, for example, those having a carboxy group, acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, etc., those having an amide group, acrylamide, methacrylamide, maleamide, etc., a hydroxyl group, As having, hydroxyethyl acrylate,
Examples of those having an N-methylolamide group such as hydroxyethyl methacrylate and hydroxypropyl acrylate include N-methylolacrylamide. These preferred composition ratios are hard monomers 20 to
20 to 80 parts by weight of the soft monomer to 80 parts by weight,
The range of 0.5 to 10 parts by weight of the functional group monomer is appropriate.

[0008] Representative examples of the present acrylic emulsion emulsion polymerization include 30-60 parts by weight of methyl methacrylate, 30-50 parts by weight of butyl acrylate, and hydroxyethyl acrylate, methacrylic acid and n-methylolacrylamide as functional group monomers. 0.5 ~
3 parts by weight, and a mixture of 0.1 to 0.5 parts by weight of tert-dodecyl mercaptan as a chain transfer agent, and 0.1 to 0.5 parts by weight of sodium dodecylbenzenesulfonate as an emulsifier
It is gradually added to distilled water containing 1.0 part by weight under stirring conditions to prepare an emulsion of the monomer. On the other hand, as in a normal emulsion polymerization method, distilled water and the same type of the same type of emulsifier are charged into a flask, stirred under a nitrogen seal, heated to 60 to 80 ° C., and mixed with 1/500 parts by weight of the monomer emulsion. The polymerization initiator is administered, and seed polymerization is performed for 20 to 30 minutes. An emulsion of the above-mentioned monomer or the like is continuously administered thereto over several hours, and after the remaining monomer is treated, cooled, alkali neutralized,
If necessary, the viscosity is increased to polyacrylic acid or polyvinyl alcohol.

The butyl carbitol used in the present invention may be a commercially available product, and its compounding ratio is from 1 to 30 parts by weight, preferably from 3 to 10 parts by weight, based on 100 parts by weight of the solid content of the acrylic emulsion. is there. If the amount is more than 30 parts by weight, problems such as a decrease in the solid content of the acrylic emulsion, a decrease in storage stability, an initial adhesive strength, and a decrease in the drying speed occur.
If less than parts by weight, drying after applying the adhesive is fast,
The hair removal of the flocking product and the flocking unevenness are remarkably lacking in practicality.
The tackifying synthetic rubber latex used in the present invention is a synthetic rubber latex containing a tackifying resin, and having 100 to 50 parts by weight of the tackifying resin in 100 parts by weight of solids in the synthetic rubber latex. Is preferred, and 15
-30 parts by weight are more preferred. More specifically, for example, a homogeneous solution containing 100 parts by weight of a tackifier resin, 2 to 10 parts by weight of a surfactant, and 10 to 100 parts by weight of an organic solvent is heated, and a synthetic rubber latex is stirred under high-speed stirring conditions. 10
It can be obtained by continuously adding 0 to 1000 parts by weight. If the amount of the tackifier resin is too small, adhesion to polypropylene is lacking. If the amount is too large, tackiness is exhibited, and problems occur in adhesive strength, heat resistance, and boiling resistance.

Examples of the above tackifying resin include ester gum S-100 (trade name, glycerin ester of modified rosin, manufactured by Arakawa Chemical Industries, Ltd.) and ester gum H
(Trade name, glycerin ester of water-added rosin, manufactured by Arakawa Chemical Industry Co., Ltd.), YS Polystar 2100 (trade name,
Terpene phenolic resin, Yasuhara Yushi Co., Ltd.) and the like. Examples of the surfactant include Neocol p (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Neugen EA-126
(Trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). In addition, examples of the organic solvent include toluene, n-hexane, dioctyl phthalate, and ethanol.

The compounding ratio of the present tackifying synthetic rubber latex is in the range of 10 to 300 parts by weight, preferably 100 to 200 parts by weight, based on 100 parts by weight of the solid content of the acrylic emulsion. When the amount is more than 300 parts by weight, the adhesiveness to polypropylene is remarkably effective, but the heat resistance and the adhesive strength are reduced, and when the amount is less than 10 parts by weight, there is no adhesiveness to the polypropylene, which is not practical. The adhesive having the above composition may be used by blending additives such as a coloring agent, an antifoaming agent, an antioxidant, a surfactant, and a thickener, if necessary.

[0012]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following, parts and percentages are by weight unless otherwise specified. The adhesive for electrostatic flocking of the present invention is a mixture of butyl carbitol and a tackifying synthetic rubber latex in an acrylic emulsion, and has an extremely high adhesion to polypropylene, a remarkably high adhesive force, and does not require the use of a primer, In thermocycles, it has a performance that can withstand the use of automotive interior materials, and because it is a water-based emulsion type, it is also excellent in terms of environmental pollution, adverse effects on the human body, dangers such as fire and explosion, etc. However, they are of very high practical value.

Examples 1 to 8 (Emulsion polymerization of acrylic emulsion) 100 parts by weight of a mixture of monomers shown in Table 1 and a mixed monomer of tert-dodecyl mercaptan were mixed with 50 parts of distilled water and 0.3 part of sodium dodecylbenzenesulfonate. The mixture was continuously administered under stirring conditions to prepare a monomer emulsion. Separately, 50 parts of distilled water and 0.2 parts of sodium dodecylbenzenesulfonate were charged in a flask, stirred under a nitrogen blanket, and heated to 70 ° C. Then, 0.4 parts of the monomer emulsion was added to After administering 0.5 part of potassium and performing seed polymerization for 30 minutes, the monomer emulsion was continuously administered over 4 hours,
Further, the remaining monomer was polymerized at the same temperature for 4 hours, cooled to 30 ° C. or less, adjusted to pH 7 with 14% aqueous ammonia, and then adjusted to 100%.
The resultant was filtered through a mesh to obtain an acrylic emulsion having a solid content of 50%. While stirring 3 parts of butyl carbitol, the acrylic emulsion was adjusted to an acrylic emulsion containing butyl carbitol used in the present invention.

[0014]

[Table 1]

(Preparation of Tackified Synthetic Rubber Latex) The composition shown in Table 2 was mixed with a condenser and a stirrer equipped with a stirrer.
It was charged into a 1-volume flask and dissolved by heating at 80 ° C. After confirming uniform dissolution, the temperature was lowered to 60 ° C and the stirring speed was set to 300 rpm.
m. Next, 600 parts of Structbond 1351 (SBR latex manufactured by Mitsui Toatsu Chemicals, solid content 48%, viscosity 150 cps, pH 7.0, glass transition temperature -30 ° C) as a synthetic rubber latex were continuously dropped at a speed of 100 g / min. Thus, a tackified synthetic rubber latex (solid content 53%, pH 7.0) used in the present invention was obtained.

[0016]

[Table 2]

Acrylic emulsions having the butyl carbitol formulations of A, B and C compositions shown in Table 1 and Table 2
Of the tackified synthetic rubber latexes A, B, and C were mixed in the proportions shown in Table 3 and sufficiently stirred and mixed. Next, an aqueous solution of partially saponified polyvinyl alcohol (manufactured by Kuraray Co., Ltd.)
(20% aqueous solution of PVA205) and 4000 cp
s. Physical properties of this adhesive were evaluated by the methods described below, and the results are shown in Table-4. 1) Polypropylene plate (manufactured by Mitsui Toatsu Chemicals, Inc., trade name: SA-15N)
F) was coated with 250 g / m ² of the adhesive of the invention. After standing at room temperature (20 ° C., 65% RH) for 10 minutes, a nylon pile (3 denier, 0.5 mm long short fiber) is put into 30K.
A voltage of V was applied and the hairs were implanted, and dried in a dryer at 70 ° C. for 45 minutes to obtain samples for evaluating physical properties. 2) Evaluation of Physical Properties 2-1) Adhesion A 1 mm square cut was made on the surface of the electrostatic flocking sample from the vertical and horizontal directions with a cutter knife to prepare 100 goban eyes. Next, a Sekisui cellophane adhesive tape was stuck thereon, and the number of eyes remaining on the substrate when forcibly peeled off was indicated by x / 100. Incidentally, 100/100 indicates perfect adhesion, and 0/100 means all peeling. 2-2) Thermocycle An electrostatic flocking sample was placed in an atmosphere of 50 ° C./95% humidity for 16 days.
Time, 8 hours in a -30 ° C. atmosphere, 16 hours in a 90 ° C. atmosphere, and 3 cycles of continuous processing at intervals of 30 minutes at room temperature. It was subjected to a sex test. 2-3) Hair removal state The surplus pile was removed from the surface of the electrostatic flocking processing sample with air at a pressure of ² kg / cm ² , and the Sekisui cellophane adhesive tape used in 2-1) was adhered to a flocking agent and forcibly peeled off. The pile depilation state was observed with a loupe and displayed as follows. ○ 1 to 3 piles adhered per 18 × 18 mm area △ 5 to 10 piles adhered to the same area × pile adhered to tape surface 2-4) Adhesive force The adhesive was applied at 250 g / m ² and immediately cotton broad #
Forty cloths were adhered and dried with a hot air drier at 70 ° C. for 45 minutes to prepare a sample for evaluating physical properties. Next, the sample was added to a length of 10
The sample was cut into 0 mm and 25 mm in width, and used as a sample for measuring adhesive strength with a Tensilon tensile tester. 23 ± 2 ° C.
Peeled at a speed of 200 mm / min in a direction of an angle of 180 ° C. in a constant temperature chamber of 65% RH and peeled off the strength to Kg / 25 m
Indicated by m.

Comparative Examples 1 to 6 The acrylic emulsion, butyl carbitol, and a tackifying synthetic rubber latex used in the present invention were blended at the ratios shown in Table 3 and physical properties were evaluated in the same manner as in the above Examples. Table 4 shows the results.

[0019]

[Table 3]

[0020]

[Table 4]

[0021]

As is evident from Table 4, the adhesive for electrostatic flocking of the present invention can obtain high adhesion and adhesion to polypropylene without using a primer agent as in the prior art, and can be used in thermocycles. In addition, it has a performance that can sufficiently withstand the use of automotive interior materials, and is excellent in terms of environmental pollution, adverse effects on the human body, dangers such as fire and explosion due to the aqueous emulsion type, and practical in terms of price Its value is extremely high and its significance is great.

Continuation of the front page (56) References JP-A-54-18845 (JP, A) JP-A-53-99247 (JP, A) JP-A-46-4132 (JP, A) JP-A-63-191874 (JP) JP-A-62-297372 (JP, A) JP-A-63-105083 (JP, A) JP-A-2-167358 (JP, A) JP-A-3-177479 (JP, A) 2-233159 (JP, A) Patent 2671049 (JP, B2) Patent 2598457 (JP, B2) Patent 2557933 (JP, B2) Patent 2716215 (JP, B2) Patent 2895132 (JP, B2) (58) Int.Cl. ⁷ , DB name) C09J 1/00-201/10 CA (STN) REGISTRY (STN) Patent file (PATOLIS)

Claims (2)

(57) [Claims] 1 to 30 parts by weight of butyl carbitol and 10 to 30 parts by weight of a tackifying synthetic rubber latex based on 100 parts by weight of a solid content of an acrylic emulsion.
An electrostatic flocking adhesive containing 0 parts by weight. 2. The synthetic rubber latex according to claim 1, wherein the synthetic rubber latex contains 10 to 50 parts by weight of a tackifying resin per 100 parts by weight of the solid content of the synthetic rubber latex.
The adhesive for electrostatic flocking described in the above.