JP2019112570A - Low out gas urethane hot melt adhesive composition - Google Patents

Abstract

To provide a hot melt adhesive composition having good wet heat resistance and low out gas property even in adhesion of an expanded material or the like.SOLUTION: There is provided a low out gas urethane hot melt adhesive composition containing an urethane prepolymer with a polyol component (A) and polyisocyanate (B) as raw materials, in which the polyol component (A) contains crystalline polyester polyol (a-1) manufactured by a condensation reaction of aliphatic dicarboxylic acid having 10 to 12 carbon atoms, and aliphatic diol having 4 to 6 carbon atoms, and polyether polyol (a-2), and content of the polyether polyol (a-2) in the polyol component (A) is 30 to 80 pts.mass based on 100 pts.mass of the polyol component (A).SELECTED DRAWING: None

Description

  The present invention relates to novel low melt out hot melt adhesive compositions.

  Conventionally, the skin material covering the surface of the seat cushion of a vehicle is made by sticking the skin layer on the surface of the laminated sheet having the back base fabric layer formed on the back surface of the foam layer made of foam and sewing further. ing. The back base cloth layer is provided to improve the slipperiness for improving the work at the time of sewing and the work at the time of attaching to the seat cushion after sewing, and for protection of the back surface of the buffer layer.

  Here, since many urethane-based or nylon-based polar materials are required for the seat cushion of a vehicle and heat resistance is required, a reactive urethane hot melt is generally applied. A vehicle seat using such a reactive urethane hot melt is disclosed, for example, in Patent Document 1.

  However, as an adhesive used for a seat cushion of a vehicle, it is desired that the organic volatile matter that affects the human body be small.

  As such a low outgassing hot melt adhesive, Patent Document 2 discloses a low outgassing olefin-based hot melt adhesive.

JP 2017-136735 Unexamined-Japanese-Patent 2017-31273

  However, although olefin-based hot melt adhesives can achieve low VOC, their use is limited from the viewpoint of heat resistance and the like, and it has been difficult to use them for vehicles and the like.

  Then, this invention makes it a subject to solve the subject of the said prior art, and to provide the hot-melt-adhesive composition which has favorable moist heat resistance and low outgassing property. Another object of the present invention is to provide a hot melt adhesive composition having sufficient initial adhesion even in adhesion of foams and the like.

  As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by using a specific adhesive composition and completed the present invention. That is, the present invention is as follows.

The present invention (1) is
It is a urethane hot melt adhesive composition containing a urethane prepolymer which uses a polyol component (A) and a polyisocyanate (B) as raw materials,
The polyol component (A) comprises a crystalline polyester polyol (a-1) comprising a condensation reaction of an aliphatic dicarboxylic acid having 10 to 12 carbon atoms and an aliphatic diol having 4 to 6 carbon atoms, and a polyether polyol (a−). 2) and contains
Low outgassing urethane hot melt adhesive composition wherein the content of the polyether polyol (a-2) in the polyol component (A) is 30 to 80 parts by mass with respect to 100 parts by mass of the polyol component (A) It is a thing.
The present invention (2) is
The crystalline polyester polyol (a-1) is the low outgassing urethane hot melt adhesive composition of the invention (1), having a number average molecular weight in the range of 1000 to 5000.
The present invention (3) is
The polyether polyol (a-2) is the low outgassing urethane hot melt adhesive composition of the invention (1) or (2), having a number average molecular weight in the range of 1000 to 4000.
The present invention (4) is
The invention (1) to (1), wherein the polyol component (A) further contains one or more polyols selected from the group consisting of amorphous polyester polyols, polycarbonate polyols and low molecular weight diols having a number average molecular weight of 500 or less. 3) The low outgassing urethane hot melt adhesive composition according to any one of the above 3).
The present invention (5) is
The total content of the non-crystalline polyester polyol, the polycarbonate diol and the low molecular weight diol having a number average molecular weight of 500 or less in the polyol component (A) is 30 parts by mass or less with respect to 100 parts by mass of the polyol component (A) It is a low outgassing urethane hot melt adhesive composition of the said invention (4).
The present invention (6) is
The low outgassing urethane hot melt adhesive composition according to any one of the inventions (1) to (5), wherein the amount of organic volatile component generated when heated at 90 ° C. is 150 ppm or less in terms of toluene.
The present invention (7) is
The low outgassing urethane hot melt adhesive composition according to any one of the inventions (1) to (6), which is for a vehicle member having a foam, a natural leather, a synthetic leather, a film, a woven fabric and a non-woven fabric.

  According to the present invention, it is possible to provide a hot melt adhesive composition having both good heat and humidity resistance and low outgassing.

Next, the hot melt adhesive composition of the present invention will be specifically described in the following order, but the present invention is not limited thereto.
1 Component 2 Production method 3 Physical property 4 Application 5 Application method

«Components»
The hot melt adhesive composition according to the present invention is a low outgassing reactive urethane hot melt. The hot melt adhesive composition according to the present invention comprises an isocyanate terminated polyurethane prepolymer as a base resin. Furthermore, if necessary, other components may be included in the adhesive composition. When such a hot melt adhesive composition is used, the adhesion property is developed by cooling and solidifying the polyurethane prepolymer in the molten state, and furthermore, the uncured isocyanate terminal reacts with the moisture in the air to form a crosslinked structure. By forming it, more firm adhesion is expressed. Hereinafter, such a hot melt adhesive composition may be referred to as a moisture-curable hot melt adhesive composition, a reactive hot melt adhesive composition, or the like.

Base resin (polyurethane prepolymer)
The polyurethane prepolymer is obtained by reacting the polyol component (A) and the polyisocyanate (B) as raw materials, and making the polyisocyanate (B) into a stoichiometric excess and reacting it with the polyol component (A). can get.

  The polyol component (A) used in the present invention essentially comprises a polyester polyol and a polyether polyol. More specifically, a crystalline polyester polyol (a-1) comprising a condensation reaction of an aliphatic dicarboxylic acid having 10 to 12 carbon atoms and an aliphatic diol having 4 to 6 carbon atoms, and a polyether polyol (a-2) And must be included.

  The crystalline polyester polyol (a-1) which concerns on this invention is a polyol which consists of a condensation reaction of a C10-C12 aliphatic dicarboxylic acid and a C4-C6 aliphatic diol. Specifically, as the aliphatic dicarboxylic acid (a-11), decanedioic acid (sebacic acid, C10), undecanedioic acid (C11) and dodecanedioic acid (C12) can be mentioned. In addition, aliphatic diols having 4 to 6 carbon atoms include butanediol (for example, 1,3-butanediol and 1,4-butanediol), pentanediol (for example, 1,5-pentanediol and the like) and hexanediol (For example, 1,6-hexanediol etc.).

  In the present invention, “crystalline polyester polyol” indicates that the melting point is 30 ° C. or higher, and “noncrystalline polyester polyol” indicates that the melting point is 30 ° C. or lower or absent. Such crystallinity can be adjusted by appropriately selecting an acid / glycol component. Here, using a differential scanning calorimeter, a melting peak in the range of -80 ° C to 100 ° C in a temperature program 25 ° C ⇒ -80 ° C C 100 ° C (heating rate 5 ° C / min) is taken as the melting point.

  The crystalline polyester polyol (a-1) preferably has a number average molecular weight in the range of 1000 to 5000, and more preferably in the range of 2000 to 4500.

  Examples of the polyether polyol (a-2) include polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol and the like obtained by polymerizing cyclic ethers such as ethylene oxide, propylene oxide and tetrahydrofuran, and copolyethers thereof. It can be mentioned. It can also be obtained by polymerizing the above cyclic ether using polyhydric alcohol such as glycerin and trimethylol ethane.

  The polyether polyol (a-2) preferably has a number average molecular weight in the range of 1000 to 4000, and more preferably in the range of 1500 to 3000.

  Moreover, it is preferable to further contain one or more polyols selected from the group which consists of a non-crystalline polyester polyol, a polycarbonate polyol, and a low molecular weight diol with a number average molecular weight of 500 or less as another polyol (a-3).

  Examples of non-crystalline polyester polyols include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid and azelaic acid, aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid and naphthalene dicarboxylic acid, and the like. Cyclic dicarboxylic acids such as hexahydrophthalic acid, hexahydroterephthalic acid and hexahydroisophthalic acid, etc., or their acid esters or anhydrides, ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol etc., or Polyester polyols obtained by dehydration condensation reaction of a mixture thereof; .epsilon.-caprolactone include polylactone diols obtained by ring-opening polymerization of lactones monomers such as methyl valerolactone.

  As a polycarbonate polyol, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexane Diethylene, at least one polyhydric alcohol such as diol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, diethylene glycol, alicyclic dihydroxy compound and the like What is obtained by making carbonate, dimethyl carbonate, diethyl carbonate etc. react is mentioned.

  The low molecular weight diol is not particularly limited as long as it is a diol having a number average molecular weight of 500 or less. For example, ethylene glycol, propanediol, 2-methyl 1,3-propanediol, 2-butyl-2-ethyl-1,3 Propanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol.

  The other polyols (a-3) may be used alone or in combination of two or more. Moreover, you may contain the polyol of that excepting the above as another polyol (a-3).

  As polyisocyanate (B), for example, tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), polymethylene polyphenyl polyisocyanate, hydrogenated MDI, 1,5-naphthalene diisocyanate, tolylene diisocyanate, 1 , 6-hexamethylene diisocyanate (HDI), isophorone diisocyanate, xylylene diisocyanate (XDI), hydrogenated XDI, tetramethylxylene diisocyanate (TMXDI), 1,8-diisocyanatomethyl octane, lysine ester triisocyanate, 1,3 , 6-hexamethylene triisocyanate, 1,6, 11 -undecane triisocyanate, bicycloheptane triisocyanate, and modified products and derivatives thereof.

  The polyisocyanate (B) may be used alone or in combination of two or more.

  Here, the NCO group content of the isocyanate-terminated polyurethane prepolymer is not particularly limited, but is preferably 1.0 to 2.5%. By setting it in such a range, it is possible to accelerate the curing by moisture while suppressing the foaming and the like during the operation. In addition, NCO group content rate is measured according to JISK1603-1.

  The content of the polyurethane prepolymer is preferably 70 to 100% by mass (more preferably 80 to 100% by mass) based on the whole composition.

-Other components As other components, well-known additives used for hot melt adhesives within the range where VOC is 150 ppm or less, for example, oil component (plasticizer), tackifier resin, antioxidant, wax Etc. can be blended. Further, a heat stabilizer, a filler, a catalyst and the like may be blended.

  Examples of oil components include paraffinic oils, naphthenic oils and aromatic oils. In addition, you may use vegetable oil etc. as an oil component.

  Tackifying resins include aliphatic petroleum resins, aromatic petroleum resins, hydrogenated aliphatic petroleum resins, hydrogenated aromatic petroleum resins, terpene resins, styrene resins, rosin resins, and modified resins thereof. And one or more tackifying resins selected from the group consisting of

  Examples of antioxidants include phenol-based antioxidants (eg, Irganox 1010 (manufactured by BASF)), sulfur-based antioxidants (eg, SUMILIZER TP-D (manufactured by Sumitomo Chemical Co., Ltd.)), phosphorus-based antioxidants, etc. (eg, , Irgafos 168 (manufactured by BASF), JP-650 (manufactured by Johoku Chemical).

  Waxes include natural waxes (eg, animal waxes (eg, beeswax, spermaceti), plant waxes (eg, wax), petroleum waxes (eg, paraffin wax), etc.) and synthetic waxes {eg, synthetic hydrocarbons (eg, synthetic hydrocarbons) (Low molecular weight polyethylene etc.), fatty acid ester (polyethylene glycol etc.) etc. can be illustrated.

  As a catalyst, a metal type catalyst, an amine type catalyst, etc. are mentioned, for example. These catalysts may be used alone or in combination of two or more.

  These additives may be used alone or in combination of two or more.

  Here, the content of the crystalline polyester polyol (a-1) in the polyol component (A) is preferably 10 to 60 parts by mass with respect to 100 parts by mass of the polyol component (A), and It is more preferable to use 40 parts by mass. By setting it as such a range, it becomes possible to maintain high solidification strength and high peeling strength.

  Moreover, content of the polyether polyol (a-2) in a polyol component (A) is 30-80 mass parts with respect to 100 mass parts of polyol components (A), and may be 40-60 mass parts. It is suitable. By setting it as such a range, coexistence of high flexibility and peel strength is attained.

  The ratio of the content of the crystalline polyester polyol (a-1) to the content of the polyether polyol (a-2) in the polyol component (A) is preferably 20:80 to 70:30. It is more preferable that it is 30:70 to 50:50.

  Furthermore, it is preferable that content of the other polyol (a-3) in a polyol component (A) is 30 mass parts or less with respect to 100 mass parts of polyol components (A). By setting it in such a range, it becomes possible to satisfy physical properties such as wet heat aging resistance and peel strength. In addition, although a lower limit is not specifically limited, For example, it is 5 mass parts with respect to 100 mass parts of polyol components (A).

«Production method»
The method for producing the moisture-curable hot melt adhesive composition according to the present invention may be a known method, and in particular, as long as the produced moisture-curable hot melt adhesive composition does not impair the object of the present invention. It is not limited.
For example, (1) a predetermined amount of isocyanate is dropped into a reaction vessel containing a predetermined amount of polyol and then heated, and the reaction is performed under the condition that the isocyanate group of the polyisocyanate is excessive to the hydroxyl group of the polyol. And adjust the polyurethane prepolymer. (2) A method of producing a desired moisture-curable hot melt adhesive composition by adding predetermined amounts of other components to the polyurethane prepolymer dropwise and stirring them may be mentioned. The reaction is carried out, for example, at a temperature of 50 to 120 ° C, preferably 60 to 100 ° C. The reaction time is, for example, 1 to 15 hours.

«Physical properties»
Next, each physical property of the hot melt adhesive composition according to the present invention will be described.

(VOC)
In the hot melt adhesive composition according to the present invention, the amount of the organic volatile component generated when heated at 90 ° C. is preferably 150 ppm or less in terms of toluene. By making VOC into this range, the regulation value can be satisfied for all the products of the vehicle seat. In addition, in order to adjust VOC, it can adjust mainly with the kind and addition amount of a polyol and a catalyst.

(Initial peel strength)
In the hot melt adhesive composition according to the present invention, it is preferable that the urethane foam and the skin material be bonded, and the peel strength after 30 seconds be 1 N / 25 mm or more (more preferably 1.3 N / 25 mm or more) . The initial peel strength can be adjusted by controlling the addition and addition amount of the non-crystalline ester polyol, polycarbonate diol and low molecular weight diol.

(Normal peel strength)
In the hot melt adhesive composition according to the present invention, urethane foam and a skin material are laminated, and the normal-state peel strength one day after is 3 N / 25 mm or more. In order to adjust the normal peel strength, it can be adjusted by the addition amount of the crystalline ester polyol and the type of other polyol component.

(Solidification time)
The hot melt adhesive composition according to the present invention preferably has a solidification time of 6 ± 4 minutes. If the setting time is too long, a material having a gap such as a knitted fabric is wound up before the adhesive solidifies, so that blocking due to the permeation of the adhesive occurs. On the other hand, when it is too short, the adhesion to the substrate is reduced and the normal peel strength is reduced. In order to adjust the solidification time, it is possible to adjust the addition amount of the crystalline ester polyol or control by the nucleating agent.

(Moisture resistant)
The hot melt adhesive composition according to the present invention preferably maintains 80% strength from the normal-state peel strength for at least 400 hours at 80 ° C. and 95%. In order to adjust moisture and heat resistance, compatibility may be improved and the ester group concentration may be reduced.

«Applications»
The hot melt adhesive composition according to the present invention is a reactive hot melt adhesive composition capable of laminating and bonding a skin material and a substrate. In particular, an adhesive layer (a layer made of a cured hot melt adhesive composition) excellent in feeling, air permeability and penetration resistance is formed when it is formed into a specific fibrous form described later. Therefore, the skin material and the base material can be applied regardless of the type, such as resin foam, resin film, synthetic leather, natural leather, woven fabric or non-woven fabric. In addition, since the substrate is also applicable to a urethane resin foam, it is applied to a long product in which a substrate made of a continuous sheet and a skin material are laminated and adhered, or in a general thermoplastic hot melt adhesive It can also be for vehicle interiors, which is difficult to apply.

«Application method»
Next, an example of an application method of the hot melt adhesive composition according to the present invention will be described. In this example, the hot melt adhesive composition is applied to a predetermined pressure-sensitive adhesive layer using a non-contact method (for example, a spray method), but the hot melt adhesive according to the present invention The application method of the composition is not limited to this, and may be applied to the surface to be adhered by a known method.

<Melting process>
First, the hot melt adhesive composition according to the present invention is held in a molten state (melting step). When the hot melt adhesive composition is moisture-curable, it is necessary to have a moisture-free atmosphere in the melting step.

<Coating process>
Next, the hot melt adhesive composition in a molten state is applied to the surface to be adhered of the adherend (preferably the surface of the foam) by a suitable application method (preferably a non-contact application method). Do. The shape at the time of specific application is not particularly limited. For example, the adhesive layer may be formed by applying in a linear shape, a dot shape, a fiber shape or the like. Besides, an adhesive layer may be formed in a sheet form. In the adhesive layer, the coating amount of the adhesive composition is preferably 5 to 50 g / m ² (more preferably 10 to 30 g / m ² ). The adhesive composition may be applied to both surfaces to be adhered.

  In addition, it does not specifically limit as a specific coating condition, For example, when using the coating method of a non-contact system as mentioned above, if it carries out by pressure 0.01-0.4MPa, temperature 100-160 ° C, etc. Good.

  Here, the non-contact coating method is a method of coating the adhesive composition without the coating equipment coming into contact with the bonding target member, and examples thereof include coating by a spray method.

  In addition, you may perform well-known pre-processing (for example, a primer process, a corona treatment, a plasma process etc.) to an adhesion | attachment object surface before a coating process.

<Contact process, curing process>
After the application step, another member is brought into contact with the surface to be adhered (application surface) provided with the adhesive layer to cool and cure the hot melt adhesive composition. In the case of a moisture-curable hot-melt adhesive composition, as described above, after curing and curing, the uncured isocyanate end reacts with moisture in the air to form a crosslinked structure, thereby exhibiting stronger adhesion. Do.

  When the hot melt adhesive composition according to the present invention is applied by the method described in the application step, adhesion is possible regardless of the adhesion target. Specifically, even if it is a resin foam, a resin film, a synthetic leather, a natural leather, a woven fabric or a non-woven fabric, it is excellent in feel, air permeability and adhesiveness, and can prevent penetration into an adhesive object. In particular, even in the case where a urethane resin foam is used as the bonding object, such an effect is exerted.

  As described above, it has a laminate having an adhesive layer which is a cured product of the hot melt adhesive composition according to the present invention, in particular, a foam and an adhesive layer provided on the surface of the foam. A laminate is obtained. In addition, it is preferable that a laminated body is a laminated body which consists of a urethane foam which is a base material, and a skin material or back base cloth as a specific structure. In such a laminate, a skin layer is preferably attached to the surface of a vehicle interior material, that is, a surface of a laminate sheet having a backing fabric layer formed on the back surface of a buffer layer made of foam {the base material). Can be used as a laminated material (laminated sheet).

  Next, the present invention will be described in more detail by way of Examples and Comparative Examples, but the present invention is not limited thereto.

<< Synthesis of Urethane Prepolymer >>
A predetermined polyol component (A) is charged into a reactor, and diphenylmethane diisocyanate and an amine catalyst are added so as to be 0.05 parts by mass with respect to the whole, and reacted at 100 ° C. for 3 to 4 hours. Thus, a urethane prepolymer having NCO% = 2.0 was obtained.

<Polyol component (A)>
Example 1
Crystalline polyester polyol (sebacic acid / butanediol) melting point 60 ° C
Number average molecular weight 4000
35 parts by mass Polypropylene glycol Addition type PO alone Number average molecular weight 2000
50 parts by mass amorphous polyester polyol (phthalic acid / neopentyl glycol)
Number average molecular weight 1000
15 parts by mass (Example 2)
Crystalline polyester polyol (dodecanedioic acid / hexanediol) melting point 70 ° C
Number average molecular weight 4000
35 parts by mass Polypropylene glycol Addition type PO alone Number average molecular weight 2000
50 parts by mass Polycarbonate diol Addition form PO alone Melting point 50 ° C
Number average molecular weight 1000
15 parts by mass (Example 3)
Crystalline polyester polyol (dodecanedioic acid / hexanediol) melting point 70 ° C
Number average molecular weight 4000
35 parts by mass Polypropylene glycol Addition type PO alone Number average molecular weight 2000
50 parts by mass Butylethylpropanediol Addition form PO alone Melting point 43 ° C
15 parts by mass (Example 4)
Crystalline polyester polyol (dodecanedioic acid / hemsan diol) Melting point 70 ° C
Number average molecular weight 4000
40 parts by mass Polypropylene glycol Addition type PO alone Number average molecular weight 2000
30 parts by mass butylethylpropanediol melting point 43 ° C.
30 parts by mass (Example 5)
Crystalline polyester polyol (sebacic acid / hexanediol) Melting point 65 ° C
Number average molecular weight 4000
20 parts by mass Polypropylene glycol Addition type PO alone Number average molecular weight 2000
80 parts by mass (Example 6)
Crystalline polyester polyol (sebacic acid / hexanediol) Melting point 70 ° C
Number average molecular weight 10000
20 parts by mass Polypropylene glycol Addition type PO alone Number average molecular weight 2000
80 parts by mass (Comparative Example 1)
Crystalline polyester polyol (adipic acid / butanediol) melting point 58 ° C
Number average molecular weight 2000
100 parts by mass (Comparative Example 2)
Crystalline polyester polyol (adipic acid / butanediol) melting point 58 ° C
Number average molecular weight 2000
30 parts by mass polypropylene glycol number average molecular weight 1000
70 parts by mass

«Evaluation»
Next, each hot melt adhesive composition obtained above was evaluated specifically by the following method. The evaluation results are shown in Table 1. In the general evaluation, if the evaluation judgment value is satisfied in all the evaluations, 、, VOC and heat and humidity resistance satisfy the evaluation judgment value, and the other evaluations do not satisfy the evaluation judgment value Δ, VOC and moisture heat resistance The case where at least one did not satisfy the evaluation judgment value was regarded as x.

<VOC>
The hot melt adhesive was put directly into a glass tube of a thermal desorption device (Marks TD-100), and outgas was measured by GC / MS (Agilent GC / MS (6890/5973)). The sample was heated at 90 ° C. for 30 minutes, and C20 was calculated using a toluene conversion value.

<Initial peel strength>
A hot melt adhesive melted at 140 ° C. is sprayed onto a urethane foam (150 × 25 × 5 mm) with a hand gun (manufactured by REKA) at 20 g / m ² to crimp the surface material. After 30 seconds, a peeling test is performed with a digital force gauge DS2 (made by IMADA) at 200 mm / min, and the maximum value is measured at N = 3 and the median value.

<Normal peel strength>
A hot melt adhesive melted at 140 ° C. is sprayed onto a urethane foam (150 × 25 × 5 mm) at 140 ° C. with a hand gun (manufactured by REKA) at 20 g / m ² to crimp the surface material. One day later, using an autograph (AG-Xplus manufactured by Shimadzu Corporation), measurement was performed at a tensile speed of 200 mm / min. A numerical value obtained by averaging the peel strengths at the maximum value and the minimum value at three points was calculated with a median of N = 3.

Solidification time
A hot melt adhesive melted at 140 ° C. at an ambient temperature of 25 ° C. is poured into a 15 g glass plate, and a thin film with a thickness of 500 μm is formed with a film applicator with a micrometer (SA-204 manufactured by Tester Sangyo Co., Ltd.). The surface was touched with a finger and the time when the tack disappeared was measured.

<Heat and humidity resistance>
A hot melt adhesive melted at 140 ° C. is sprayed onto a urethane foam (150 × 25 × 5 mm) at 140 ° C. with a hand gun (manufactured by REKA) at 20 g / m ² to crimp the surface material. After 3 days, let stand at 80 ° C. and 95% environment, and measure the peel strength every 100 h. The time from the normal peel strength to 80% maintained was measured.

Claims (7)

It is a urethane hot melt adhesive composition containing a urethane prepolymer which uses a polyol component (A) and a polyisocyanate (B) as raw materials,
The polyol component (A) comprises a crystalline polyester polyol (a-1) comprising a condensation reaction of an aliphatic dicarboxylic acid having 10 to 12 carbon atoms and an aliphatic diol having 4 to 6 carbon atoms, and a polyether polyol (a−). 2) and contains
The low outgassing urethane hot material, wherein the content of the polyether polyol (a-2) in the polyol component (A) is 30 to 80 parts by mass with respect to 100 parts by mass of the polyol component (A). Melt adhesive composition.   The low outgassing urethane hot melt adhesive composition according to claim 1, wherein the crystalline polyester polyol (a-1) has a number average molecular weight in the range of 1000 to 5000.   The low outgassing urethane hot melt adhesive composition according to claim 1 or 2, wherein the polyether polyol (a-2) has a number average molecular weight in the range of 1000 to 4000.   The polyol component (A) further contains one or more polyols selected from the group consisting of amorphous polyester polyol, polycarbonate polyol and low molecular weight diol having a number average molecular weight of 500 or less. A low outgassing urethane hot melt adhesive composition according to any one of the preceding claims.   The total content of the non-crystalline polyester polyol, the polycarbonate diol and the low molecular weight diol having a number average molecular weight of 500 or less in the polyol component (A) is 30 parts by mass or less with respect to 100 parts by mass of the polyol component (A) The low outgassing urethane hot melt adhesive composition according to claim 4.   The low outgassing urethane hot melt adhesive composition according to any one of claims 1 to 5, wherein the amount of organic volatile component generated when heated at 90 ° C is 150 ppm or less in terms of toluene. The low outgassing urethane hot melt adhesive composition according to any one of claims 1 to 6, which is for vehicle members having foam, natural leather, synthetic leather, film, woven fabric and non-woven fabric.