JP3283306B2 - Adhesive composition for electrostatic flocking - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive for electrostatic flocking of a weatherstrip member used for a vertical opening / closing portion of a window glass of an automobile. More specifically, in a two-part adhesive using an aqueous emulsion and an isocyanate-based curing agent in combination, the usable time of the adhesive, that is, the time required for the viscosity to rise with time and the time to become unusable due to foaming with carbon dioxide gas is long. And has adhesive properties such as wettability, adhesion, water resistance, heat resistance, moisture resistance, boiling resistance, and wax removal resistance to vinyl chloride; environmental pollution, occupational safety, and the danger of fire, etc. The present invention relates to an extremely small amount of an aqueous emulsion type adhesive for electrostatic flocking.

[0002]

2. Description of the Related Art It is well known that, since a weather strip material is mainly made of vinyl chloride resin, a nylon pile is conventionally subjected to electrostatic flocking at a high voltage using a solvent type two-component urethane adhesive having excellent adhesiveness. Like. Recently, due to various problems such as environmental pollution, occupational safety and fire, and danger of fire, the solvent-based adhesives are becoming water-based or hot-melt as in Europe and the United States. In this flow, studies on aqueous emulsion adhesives have been actively conducted as the first step.

[0003]

Specifically, attention is paid to urethane resin which is excellent in adhesion to vinyl chloride, and urethane dispersion and the like are used as a main agent, an amine-based curing agent is used in combination, and an acrylic emulsion is used as a main agent in order to prevent pollution. Attempts have been made with water-based adhesives in which an epoxy-based curing agent is used in combination and an ethylene-vinyl acetate-based copolymer emulsion is used in combination with 4,4'-diphenylmethane diisocyanate. In the laboratory scale test, these adhesives have the strength to be provided by a weatherstrip in the electrostatic flocking state, adhesion to vinyl chloride, abrasion resistance, etc. When processed with an electric flocking machine, work problems such as pot life on the vinyl chloride surface, cissing, uniform coating properties, uneven flocking due to drying of the adhesive, etc. occur, as well as water resistance, heat resistance, moisture resistance, Lack of adhesive properties such as boiling resistance, especially when immersed in a highly alkaline aqueous solution of a wax remover, there is a big problem that the pile with electrostatic flocking easily peels off in several abrasion tests, leading to its practical use. Not in. Among the above-mentioned adhesives, a combination of an ethylene-vinyl acetate copolymer emulsion and 4,4'-diphenylmethane diisocyanate may be mentioned as having a practical level in terms of the physical properties of the electrostatic flocking process. The time has become extremely short, and solving work problems has been an issue.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above problems, and as a result, have found that ethylene-vinyl acetate
Focusing on the fact that the copolymer emulsion has excellent adhesiveness with vinyl chloride, by blending a non-yellowing urethane prepolymer with a slow reaction rate, the pot life is extended and the adhesive properties are not adversely affected, In addition, by blending carbon black with the prepolymer, an adhesive having a color tone similar to that of vinyl chloride can be obtained, the gloss of the adhesive layer is suppressed, and the commercial value does not decrease even if some flocking unevenness occurs. On the other hand, it was found that the compounding of the glycidyl-based silane coupling agent was extremely effective in water resistance, heat resistance, moisture resistance, boiling resistance, and wax removal resistance. Furthermore, they found that surfactants with low interfacial tension were effective in imparting wettability, ie, cissing on the vinyl chloride surface and uniform coating properties, and concluded that these compounds were excellent as weatherstrip adhesives. Thus, the present invention has been completed. That is, the present invention
a. Ethylene- vinyl acetate is added to the weatherstrip material of a car with a metal plate as the core material and extruded vinyl chloride.
Aliphatic polycarboxylic respect alcohol copolymer emulsion 100 parts by weight
Isocyanate water adduct or polyhydric alcohol adduct
1 to 30 parts by weight of a urethane prepolymer of
Glycidyl silane coupling rig agent 0.1-5 parts by weight, the field
Electrostatic flocking adhesive composition, which comprises using an adhesive surface active agent by blending 0.01 to 50 parts by weight. b.
The adhesive composition for electrostatic flocking according to the above item a, wherein the ethylene-vinyl acetate copolymer emulsion is an emulsion having a glass transition temperature of -20 to + 22 ° C. c.
a. The adhesive composition for electrostatic flocking described in the above, further comprising carbon
Black is a water adduct of the aliphatic polyisocyanate.
Or polyhydric alcohol adduct type urethane prep
5 to 200 parts by weight per 100 parts by weight of rimer
An adhesive composition for electrostatic flocking, comprising: d. World
The adhesive composition for electrostatic flocking described in a above, wherein the surfactant is an anionic or nonionic surfactant. Ethylene-vinyl acetate copolymer used in the present invention
Body emulsion emulsion, port polyvinyl alcohol
, Hydroxymethylcellulose, hydroxyethyl cellulose
Water-soluble components such as cellulose and carboxymethylcellulose
High temperature and high pressure
A method using ethylene and vinyl acetate under a known pressure cooker
-Ethylene-vinyl acetate copolymer obtained by emulsion polymerization
Emulsion emulsion (hereinafter abbreviated as EVA system)
means. The glass transition temperature of the EVA system is -20 to +2.
It is in the range of 2 ° C, preferably in the range of 0 to + 3 ° C. When the temperature is below -20 ° C, the resin itself has low cohesive strength and fat
Water adduct of polyisocyanate or polyhydric alcohol
Even if a urethane prepolymer of the lua-duct type is used in combination, it lacks adhesive strength and heat resistance, and when the temperature is + 22 ° C or more, it is too hard, lacks flexibility, and reduces the texture (texture).
In particular, under a low temperature, when a bending test is carried out, cracks are formed, which is not practical. Aliphatic poly used in the present invention
Isocyanate water adduct or polyhydric alcohol adduct
Examples of the urethane prepolymer of the urethane type include a water adduct type or a polyhydric alcohol adduct type of a polyisocyanate compound represented by hexamethylene diisocyanate (HDI) having a low reaction rate. The aliphatic polyisocyanate
Water adduct or polyhydric alcohol adduct type c
The viscosity of the urethane prepolymer is not particularly limited.
A resin having a resin solid content of 50 to 80% whose viscosity is adjusted with a mixed solvent of ethyl acetate or cellosolve acetate and xylene in a range of 100 to 600 poise is preferable from the viewpoint of easy incorporation into a system. Further, the NCO content (%) is not particularly limited, but is preferably 12 to 18% from the viewpoint of extending the pot life. A water adduct of the aliphatic polyisocyanate or
Or polyhydric alcohol adduct type urethane prepoly
The mixing ratio of the mer is 1 to 100 parts by weight of the EVA system.
The range is from 30 to 30 parts by weight, preferably from 5 to 20 parts by weight. Less than 1 part by weight has no effect on adhesive strength, water resistance, heat resistance, moisture resistance, boiling water resistance, and wax removal resistance. And the adhesive layer is cracked in a bending test, resulting in lack of practicality. Further, the aliphatic polyisocyanate used in the present invention
Water adduct or polyhydric alcohol adduct type
The structure of the urethane prepolymer contains carbon black as described below.

[0005] The carbon black used in the present invention is not particularly limited, but it is easy to be incorporated into a non-yellowing type urethane polymer, and furthermore, an aliphatic polyisocyanate containing carbon black.
Anate water adduct or polyhydric alcohol adductor
It is preferable that the urethane prepolymer of Ip be pasted with a plasticizer such as dioctyl phthalate (DOP) or dibutyl phthalate (DBP) because of easy dispersibility in EVA system. Aliphatic polyisocyanate of the carbon black
Water adduct or polyhydric alcohol adduct tie
Proportion to the urethane prepolymer flop, relative to 100 parts by weight of 75% resin solids of the urethane prepolymer, from 5 to 20 as a 75% carbon black paste
0 parts by weight, preferably in the range of 50 to 100 parts by weight. If the amount is less than 5 parts by weight, it is difficult to obtain the same color as vinyl chloride when applied to vinyl chloride, and if flocked unevenness occurs, gloss is observed in the flocked portion and the commercial value is significantly reduced. If the amount is more than 200 parts by weight, the viscosity of the urethane prepolymer becomes remarkably high, which hinders the work at the time of blending into the EVA system, and also lowers the uniform coatability, which is not practical. Aliphatic polyisocyanes thus obtained
Water adduct or polyhydric alcohol adduct type
The urethane prepolymer used as the EVA-based curing agent or crosslinking agent. Water of aliphatic polyisocyanate
Adduct or polyhydric alcohol adduct type urethane
It is desirable that the prepolymer is blended immediately before the electrostatic flocking process. The glycidyl-based silane coupling agent used in the present invention includes γ-glycidoxypropylmethyldiisopropenoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyldiethoxysilane, and the like. Among these, γ-glycidoxypropyltrimethoxysilane is preferred from the viewpoint of the stability at the time of blending into EVAC, and the effects of improving boiling resistance and wax removal agent resistance. The mixing ratio of the glycidyl-based silane coupling agent is 0.1 to 5 with respect to 100 parts by weight of the EVA-based.
Parts by weight, preferably in the range of 0.2 to 0.5 parts by weight. When the amount is less than 0.1 part by weight, the wax-removing agent resistance and boiling resistance are lacking. When the amount is more than 5 parts by weight, the stability at the time of blending with the EVA emulsion, that is, the pot life is remarkably shortened. The price of the adhesive is extremely high, and is not practical. Formulations of the present glycidyl based silane coupling agent, water Adaku of the aliphatic Poriisoshia sulfonate
Or polyhydric alcohol adduct type urethane pre
Similar to the polymer compounding, it is performed immediately before the electrostatic flocking process, but the order of addition does not matter. The surfactant of the present invention is used for the purpose of imparting repelling and leveling properties, that is, uniform coating properties, to vinyl chloride which is usually previously blended in an EVA system.

As anionic and nonionic surfactants
Include dialkyl as interfacial tension and type is low foaming, dialkyl sulfosuccinate sodium salt, naphthalenesulfonic acid formalin condensate, include polyethylene glycol nonylphenyl ether, as a significant effect especially small compounding Sulfosuccinate soda salts are preferred. The mixing ratio of the surfactant is in the range of 0.1 to 10 parts by weight based on 100 parts by weight of the EVA system. When the amount is less than 0.1 part by weight, there is no effect on the improvement of the flocking unevenness due to repelling and uniform coating property, and
When the amount is more than the weight part, the viscosity of the adhesive is decreased, and it is difficult to apply the adhesive uniformly to a predetermined application amount, and uneven flocking occurs, the commercial value of the weatherstrip member is remarkably reduced, and practicality is lacking. The adhesive thus obtained is used as the core of a metal plate,
Using a spinning wheel-shaped roll coater on the flocking section of the weatherstrip base material that was extruded and molded from PVC,
Apply evenly to a coating amount of 150 g / m2, and immediately
Denier, a fine nylon pile with a length of 0.8 mm is applied with a high voltage of 30 to 50 KV, and the hair is planted.
After drying in a hot air dryer having a temperature gradient of 0 ° C. for 2 to 3 minutes,
By curing at room temperature for 3 days or more, workability such as cissing and uniform coating property of the vinyl chloride surface is remarkably improved, and adhesion, water resistance, heat resistance, moisture resistance, boiling resistance and high alkali resistance are improved. An electrostatic flocking product of a weather strip for automobiles having excellent wax removing agent properties and the like is obtained, and the present invention using a foldable, water-based emulsion as a skeleton having a strict solvent regulation is used for the adhesive for electrostatic flocking of the automobile. It is very significant as an agent and its practical value is high.

[0007]

EXAMPLES In order to explain the present invention more specifically,
EXAMPLES Examples, comparative examples, and production examples will be described, but the present invention is not limited to these examples. In the following, parts and percentages are by weight unless otherwise specified. Production Examples 1 to 6 (Carbon black-containing aliphatic
Water adduct of polyisocyanate or polyhydric alcohol
Preparation of adduct-type urethane prepolymer ) In a 500 cc flask equipped with a stirrer, put the aliphatic polyester having the ratio shown in Table 1.
Water adduct of polyisocyanate or polyhydric alcohol
A duct type urethane prepolymer and a carbon black paste (manufactured by Dainichi Seika Co., Ltd.) containing a 75% concentration of carbon black obtained by kneading a plasticizer and carbon black using a roll are charged and stirred and kneaded under a nitrogen seal. Water of aliphatic polyisocyanate containing carbon black
Adduct or polyhydric alcohol adduct type urethane
A prepolymer was obtained.

[0008]

[Table 1] Olester NP1000: Mitsui Toatsu Chemical Co., Ltd., HDI water adduct, NCO 17% xylene / cellosolve acetate diluted viscosity 250 poise orester NP2000: 〃 HDI polyhydric alcohol adduct, NCO 12.5%, ethyl acetate diluted Viscosity 400 centipoise

Examples 1 to 13 EVA was used at the ratios shown in Table 2.
A humectant is previously blended into the system, and then the fat obtained in Production Examples 1 to 6
Water adduct or polyvalent alcohol of aliphatic polyisocyanate
Knead a urethane prepolymer of
Finally, a silane coupling agent was blended to obtain an adhesive for electrostatic flocking. This adhesive was applied to a flocking site of a weatherstrip base material coated with vinyl chloride at a coating amount of 150 g / m2 with a roll coater, and immediately using a hand-held electrostatic flocking machine, Elo Floc (Germany), A 3-denier, 0.8 mm long nylon pile was dropped under a high voltage of 35 KV and planted for hair, dried with a hot air drier at 100 ° C. for 3 minutes and cured at room temperature for 3 days to prepare an electrostatic flocking test specimen. The following adhesive property evaluation tests were performed, and the results are shown in Tables 4 and 5.

[0010]

[Table 2]

Physical property test evaluation method Pot life measurement After adjusting the adhesive for electrostatic flocking, leave it in an atmosphere of 40 ° C. and adjust the foaming amount or viscosity of the initial 1.5
The time until the viscosity increased by a factor of two was measured and displayed in hours (minutes). 2. Using a roll coater on the surface of vinyl chloride suitable for application,
An adhesive of 150 g / m ² was uniformly applied, and the occurrence of repelling or streaks was observed and displayed as follows. ：: The coating surface is uniform and there is no abnormality. Δ: Slight repelling or streaking occurred. ×: Repelling or streaking occurred on the entire surface. 3. Adhesion test width 24 mm, was cut weather strip substrate in the length 100 mm, the adhesive 150 g / m ² on a vinyl chloride surface bonded to cotton fabric coated immediately No40, after 3 minutes drying at 100 ° C. hot air dryer After curing at room temperature for 3 days, the film was subjected to the following test, and the adhesive strength was represented by 180 ° peel strength per kg / 25 mm. 3-1 Normal adhesive strength: Measured at a pulling speed of 100 mm / min using an Intesco tensile tester in a 23 ° C. atmosphere immediately after curing for 3 days. 3-2 Heat resistance: Measured in a 90 ° C atmosphere according to the measurement method of 3-1. 3-3 Water resistance; 3-1 after immersion in 20 ° C city water for 30 minutes
Measured according to the measurement method. 3-4 Moisture resistance; 2 at 50 ° C and 65% humidity
After standing for 4 hours, immediately measure according to the measurement method of 3-1. 4. Boiling resistance: Immediately after immersing the flocking product in boiling water for 2 hours, water-cooling, rubbing the flocking surface 10 reciprocations with a 10 yen coin, observing the presence or absence of hair loss, and displaying as follows. ：: No abnormality. Δ: Partial hair loss. ×: Complete hair removal or adhesive peeling. 5. Wax remover resistance; wax remover ST2
10 (manufactured by Yushiro Chemical Industry Co., Ltd.) was diluted twice with water, and the flocking product was immersed for 30 minutes and immediately washed with water for 2 minutes.
Subject to the same test and indicate similarly. 6. Flexibility: Flocked part is bent and displayed by finger touch as shown below. ：: Flexible. Δ: slightly hard. X: Hard. 7. Adhesive color tone: Flocked product was bent and the color tone of the base was visually observed. ：: Close to vinyl chloride. Δ: Slightly glossy. X: Large gloss. Comparative Examples 1 to 8 Adhesives were adjusted at the ratios shown in Table 3 according to Example 1, and physical properties were evaluated in the same manner as in Examples. The results are shown in Table 5.

[0012]

[Table 3]

[0013]

[Table 4]

[0014]

[Table 5]

[0015]

As is clear from Tables 4 and 5, the adhesive composition for electrostatic flocking of the weatherstrip of the present invention is as follows.
Due to the use of adhesives based on aqueous emulsions,
Environmental pollution, fire,
Problems such as occupational safety and hygiene are significantly reduced, and workability when applying the adhesive, that is, the pot life at high temperatures is significantly extended and the repellency and uniform applicability are excellent. The rejection rate is remarkably reduced, the commercial value is increased, and at the same time, the environment such as water resistance, heat resistance, moisture resistance, boiling resistance, and anti-waxing properties, which should be provided as a flocked body of automotive weatherstrips Since it is also excellent in the test, it is extremely significant as the method for electrostatic flocking of the automobile, and its practical value is high.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C09J 175/04 B60J 10/04 C08J 5/12

Claims (4)

(57) [Claims] 1. A metal plate as a core material, an automobile weather strip substrates molded extruding vinyl chloride, d
A water adduct of an aliphatic polyisocyanate or 100 parts by weight of a tylene-vinyl acetate copolymer emulsion or
Adhesion in which 1 to 30 parts by weight of a polyhydric alcohol adduct type urethane prepolymer , 0.1 to 5 parts by weight of a glycidyl silane coupling agent , and 0.01 to 5 parts by weight of a surfactant are blended. An adhesive composition for electrostatic flocking, characterized by using an agent. 2. An ethylene-vinyl acetate copolymer emulsion.
The adhesive composition for electrostatic flocking according to claim 1, wherein the emulsion is an emulsion having a glass transition temperature of -20 to + 22 ° C. 3. The adhesive composition for electrostatic flocking according to claim 1.
Further, carbon black is added to the aliphatic polyisocyanate.
Water adduct or polyhydric alcohol adduct tie
5 to 2 parts by weight of urethane prepolymer 100 parts by weight
Contact parts for electrostatic flocking characterized by pre-mixing with 00 parts by weight
Adhesive composition. 4. The adhesive composition for electrostatic flocking according to claim 1, wherein the surfactant is an anionic or nonionic surfactant.