JP3066062B2 - Adhesive processing of seats - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a method of bonding a seat, and more particularly, to a seat by using a moisture-curable hot-melt adhesive having an initial cohesion and a low modulus. The present invention relates to a method for bonding a seat, which can maintain the feel of a seat material, and can be rapidly cured by using steam in combination with hot pressing.

Topics to be solved by the prior art and the invention Due to the demand for high-grade automotive interior materials and high designability, a processing method with excellent design that adheres the skin material to the cushion base material even for seats is required. Widespread. At present, a solvent-type urethane-based adhesive is used in the bonding method, but there are problems in environmental hygiene and safety, and therefore, a demand for solvent-free is increasing.

Means for Solving the Problems The present inventors have conducted intensive studies to meet such a demand, and found that a polyethylene oxide block or a polyalkylene oxide block containing a terminal end of a polyethylene oxide block and a glass transition point (Tg) via a diisocyanate compound. The block type isocyanate group-containing urethane prepolymer having a structure in which polyester blocks having a high degree of specific arrangement are formed is sensitive to temperature drop, generates initial cohesion, and has high reactivity to moisture. The present invention has also been found to have physical properties (low modulus) that do not impair the feel of a seat material (for example, urethane foam) after reaction curing even when used as a hot-melt adhesive in the method, and have completed the present invention.

That is, the present invention relates to a method of preparing a polyethylene oxide block or a polyalkylene oxide block (A) having a polyethylene oxide block at an end and a polyester block (B) having a Tg of 100 ° C. Moisture curing characterized by comprising a blocked isocyanate group-containing urethane prepolymer having a block structure represented by the formula: ABA, bonded via a diisocyanate compound (hereinafter, referred to as a block NCO prepolymer). Hot-melt adhesive, and a method of processing a seat sheet comprising a skin material adhered to a cushion base material,
An object of the present invention is to provide a method for bonding a seat, wherein the moisture-curable hot-melt adhesive is spray-coated on a cushion base material, and then a skin material is overlapped and bonded by hot pressing.

The block NCO prepolymer in the present invention is obtained, for example, by mixing polyethylene glycol or a block type polyoxyethylene-alkylene polyol having a polyethylene oxide block at the end (hereinafter, referred to as block polyol) with an excess amount of a diisocyanate compound.
The reaction was carried out (usually at 50 to 100 ° C. for 1 to 24 hours) so that the NCO / OH ratio was greater than 1 (preferably 1.2 to 3.0) to obtain a non-terminal isocyanate group-containing urethane prepolymer. A polyester polyol at a temperature of 100100 ° C. (preferably 5-50 ° C.) has an end NCO / OH of more than 1 (preferably 1.2-3.
0) (usually at 50 to 120 ° C for 1 to 24 hours)
It can be manufactured by doing.

In addition, in the formula showing the above block structure, the polyethylene oxide block in A contributes to lower modulus, and the polyester block in B contributes to the development of initial cohesive force.

The block polyol is a low molecular weight active hydrogen compound having two or more active hydrogens (eg, ethylene glycol, propylene glycol, butylene glycol,
Diols such as 6-hexanediol, glycerin,
Alkylene oxide (propylene oxide, propylene oxide, trimethylolpropane, triols such as 1,2,6-hexanetriol, and amines such as ammonia, methylamine, ethylamine, propylamine, and butylamine). And a block copolymer obtained by ring-opening polymerization of ethylene oxide. Those having a molecular weight of 200 to 2000 are used.

Examples of the diisocyanate compound include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, and 1,3-cyclohexane. Pentane diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 4,4'-methylene bis (cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, methyl 2,6-cyclohexane diisocyanate, 1,4-bis ( Isocyanatomethyl) cyclohexane, 1,3-bis (isocyanatomethyl) cyclohexane, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4 '-Diphenyl diisocyanate, 1,5-naphthalenediisocyanate, 4,4'-diphenylmethane diisocyanate, crude diphenylmethane diisocyanate, 2,4- or
2,6-tolylene diisocyanate, 4,4'-toluidine diisocyanate, dianidin diisocyanate, 4,4 '
-Diphenyl ether diisocyanate, 1,3- or
Examples thereof include 1,4-xylylene diisocyanate and ω, ω′-diisocyanate-1,4-diethylbenzene, and one or more of these are used. Particularly, in the present invention, use of 4,4'-diphenylmethane diisocyanate (MDI), tolylene diisocyanate, or the like is preferable.

The polyester polyol is a polybasic acid (for example, phthalic acid, adipic acid, terephthalic acid, isophthalic acid, sebacic acid, dimerized linoleic acid, maleic acid, and di-lower alkyl esters thereof) and a polyhydroxy compound (for example, Diols and triols, and diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, and the like). A material having a Tg of 0 to 100 ° C. and a molecular weight of 500 to 30,000 is used.

The moisture-curable hot-melt adhesive according to the present invention is composed of the block NCO prepolymer and, if necessary, further comprises a tackifier resin (rosin resin, rosin ester resin, hydrogenated rosin ester resin, terpene resin, terpene). Fehl resin, hydrogenated terpene resin, petroleum resin, etc.), filler (silicic acid derivative, talc, metal powder, calcium carbonate, clay, carbon black, etc.), plasticizer (dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, diisooctyl) Phthalate, diisodecyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, trioctyl phosphate, epoxy plasticizer, toluene-sulfonamide, chloroparaffin, adipate ester, castor oil, etc., thixotropic agents (benton, silicic anhydride, silicic acid) Invitation Body, and urea derivatives), dyes and pigments, curing catalysts, ultraviolet absorbers, flame retardants, silane compounds, etc. may be appropriate amount of dehydrating agent.

In order to bond a seat using the adhesive of the present invention, the following procedure may be performed.

First, the adhesive of the present invention is applied to the surface of a cushion base material (eg, urethane foam, fabric, knitted urethane foam, etc.) which is one of the seat materials.
After melting at 100-120 ° C, spray coating is usually performed at an amount of 30-100 g / m ² , and then another skin material (for example, urethane foam, fabric, urethane foam with knitting, etc.) is laminated, and usually 50 Hot pressing is performed under the condition of 〜100 ° C. In this case, since both the cushion base material and the skin material of the seat material are excellent in heat insulation, by using steam in combination with hot pressing, the curing can be promoted by supplying moisture and heat. After the hot pressing (and the combined use of steam), moisture curing is performed under normal temperature and normal humidity to obtain a seat with low modulus and good texture.

Next, the present invention will be described more specifically with reference to examples and comparative examples.

Example 1 To 100 g of polyethylene oxide (Exenol 550, manufactured by Asahi Glass Co., Ltd.) was added 60 g of MDI (NCO / OH = 2.3), and the mixture was reacted at 80 ° C. for 5 hours to obtain a urethane prepolymer containing an unterminated isocyanate group. 930 g of polyester all (Nippon Synthetic Chemical Industry Co., Ltd., Polyester LP-035, Tg20 ° C)
(Negative NCO / OH = 2.3) and further reacted at 120 ° C. for 4 hours to obtain a block NCO prepolymer.

Example 2 Polyethylene glycol (manufactured by Sanyo Chemical Industries, Ltd., PE
G400) 145 g of MDI was added to 100 g (NCO / OH = 2.3) and reacted at 80 ° C. for 5 hours to obtain a urethane prepolymer containing terminal isocyanate groups. Then, a polyester polyol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., Polyester LP-033, Tg15 ℃) 2
250 g is added (terminal NCO / OH = 2.3) and further reacted at 120 ° C. for 4 hours to obtain a block NCO prepolymer.

Comparative Example 1 To 100 g of the polyester polyol (Polyester LP-035) used in Example 1, 3.75 g of MDI was added (NCO / OH = 2.
4) The reaction is carried out at 120 ° C. for 4 hours to obtain a urethane prepolymer containing an unterminal isocyanate group.

Dumbbell Physical Properties Test The target prepolymers obtained in Examples 1 and 2 and Comparative Example 1 were formed into a 0.8 mm thick sheet and cured at 20 ° C. and 65% RH for 168 hours, followed by 50% modulus, elongation and breaking strength. Was measured. The results are shown in Table 1 below.

Example 3 and Comparative Example 2 (Adhesion Processing Method) The objective prepolymers of Examples 1 and 2 and Comparative Example 1 were each heated and melted at 120 ° C., and these were melted into a polyurethane foam (300 × 300 × 30 mm) at 50 g / m _2. Spray in quantity.
Next, the fabric (300 x 300 x 4 mm) is overlaid on the polyurethane foam coating surface and pressed with a press molding machine consisting of an upper plate and a lower plate. At the same time, a steam blow hole (2.5 mmφ) is formed on the lower plate. Blow down steam at 80 ° C for 1 minute.

Thereafter, the composition is subjected to moisture curing by curing at 20 ° C. and 65% RH for 24 hours, and is subjected to the following heat creep resistance test. The results are shown in Table 1 below.
Shown in

Heat resistance creep resistance test Measure 180 ° peel length (mm) after 24 hours at 300g load in 80 ° C atmosphere.

In addition, the result of the case where the steam press at 80 ° C. without steam for 1 minute is used instead of the steam press at the time of the above-described pressurization is also described.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-4-89880 (JP, A) JP-A-50-51544 (JP, A) JP-A-50-58149 (JP, A) JP-A-58-58 38723 (JP, A) JP-A-57-131275 (JP, A) JP-A-5-505846 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C09J 1/00-201 / 10 C08G 18/00-18/87 A47C 3/00 B60N 2/00

Claims (3)

(57) [Claims] 1. An urethane prepolymer containing an unterminated isocyanate group by reacting an excess amount of a diisocyanate compound with polyethylene glycol or a block type polyoxyethylene-alkylene polyol having an unterminated polyethylene oxide block to obtain a glass transition. Point 0
Polyester polyol at ~ 100 ° C with unfinished NCO / OH ratio of 1
An excess of a polyethylene oxide block or a polyalkylene oxide block (A) having a polyethylene oxide block at the end and a polyester block (B) having a glass transition point of 0 to 100 ° C. obtained by reacting to a larger extent. A moisture-curable hot-melt adhesive comprising a blocked isocyanate group-containing urethane prepolymer having a block structure represented by the formula: ABA, which is bonded via an amount of a diisocyanate compound. 2. A method for processing a seat, comprising: bonding a skin material to a cushion base material; and applying the hot melt type adhesive according to claim 1 to the cushion base material by spraying, and then laminating the skin material. And bonding by hot pressing. 3. The bonding method according to claim 2, wherein steam and heat are used together in hot pressing to accelerate heating and curing.