JP2007130936A - Method for manufacturing interior parts for automobile and interior material for automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an interior part for an automobile not only holding good initial adhesivity but also holding the adhesivity even under environment where temperature fluctuation on the panel surface is large and an interior material for an automobile. <P>SOLUTION: The method for manufacturing the interior part for the automobile comprises the steps of: applying a flame treatment to a core material composed of a polyolefin resin, coating an adhesive containing a binding agent and a polyester-plyol having hydroxy groups at both the ends and an average molecular weight of 400-700, molding together with the core material applied with the adhesive and disposed in a mold by injecting a non-foaming urethane reaction liquid onto the surface side coated with the adhesive to be reacted in the mold. The interior material for the automobile is manufactured by the method for manufacturing the interior part for the automobile. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an automotive interior part and an automotive interior material that are excellent in adhesion between a base material and a surface layer.

  In recent automobiles, an airbag device is incorporated from the viewpoint of ensuring the safety of the occupant, and not only the steering wheel for the driver's seat and the instrument panel for the passenger's seat, but also the occupant's side portion Side airbags are also provided to protect against impacts.

  Airbag devices are usually placed inside interior panels to ensure the aesthetics of the interior, and when an automobile is impacted, the impact is detected and the airbag is inflated and deployed. In this way, the vehicle is interposed between the passenger and the passenger, thereby protecting the passenger. That is, the airbag is normally hidden from the appearance by the interior panel, and when an impact is detected, the interior panel needs to be broken when the airbag is inflated.

  For this reason, it has become necessary for the interior panel to ensure the aesthetic and tactile sensations that have been conventionally required, and to ensure reliable breakability when the airbag operates.

Various studies have been made as a method for making these compatible. Cited Document 1 is an example showing a method of manufacturing a panel for the purpose of incorporating an airbag, and discloses a method of applying an adhesive to a base material of an interior material and forming it using a polyurethane molding material. ing.
JP 2005-104319 A

  However, even when the above technique is implemented, the temperature inside the vehicle rises extremely when the automobile is left outdoors, especially in summer. Such an increase in temperature reduces the adhesion of the urethane skin that is adhered to the substrate. Furthermore, when polyolefin resin, chlorinated polyolefin resin, etc. are used as the base material of the interior material, adhesion can be secured in the initial stage, but adhesion is reduced when exposed to such high temperatures. There was something to do. For this reason, management in the manufacturing process has been strictly performed so that the adhesion does not deteriorate. As a result, productivity is poor and manufacturing costs are increased.

  As a result of intensive studies by the present inventors, it has been found that the above-mentioned problems can be solved by using an adhesive having a specific composition, and the present invention has been achieved.

That is, according to the present invention, a step of subjecting a core material made of polyolefin resin to flame treatment,
A step of applying an adhesive containing a binder and a polyester polyol having a number average molecular weight of 400 to 700 having hydroxyl groups at both ends to the flame-treated core material surface;
A step of disposing the core material coated with the adhesive in a mold, injecting a non-foamed urethane reaction liquid onto the surface coated with the adhesive, reacting in the mold, and molding the core material integrally with the core material When,
There is provided a method of manufacturing an interior part for an automobile characterized by comprising:

Further, according to the present invention, a core material having a scheduled door for inflating an airbag made of polyolefin resin,
A skin material made of non-foamed urethane,
An adhesive layer containing a binder and a polyester polyol having a number average molecular weight of 400 to 700 having a hydroxyl group at both ends between the core material and the skin material;
An interior material for an automobile is provided.

  The interior material obtained by carrying out the present invention not only maintains good initial adhesion, but also can maintain the adhesion even in an environment where the temperature of the panel surface is drastically changed. Therefore, even when the interior panel is placed in a low temperature environment of about −40 ° C. or a high temperature environment of about 80 ° C., it is possible to maintain good adhesion.

  Moreover, in this invention, it becomes possible to obtain the interior material excellent in the designability and the touch.

  The method for producing an interior material according to the present invention includes a step of performing a flame treatment on a core material made of a polyolefin resin, a step of applying an acrylic adhesive on the surface of the core material subjected to the flame treatment, The core material to which the adhesive is applied is put into a mold, and the process comprises injection molding of non-foamed urethane.

  The step of obtaining the core material can be obtained by injection molding a polyolefin resin by injection molding. The polyolefin resin to be used will be described later. As the mold to be used, any of the molds usually used in injection molding can be used, and the form can be appropriately changed depending on the shape of the interior material required. In addition, by providing a protrusion inside the mold and partially reducing the thickness of the core material, it is possible to provide a planned airbag bulging door portion. In this way, by partially reducing the thickness of the core material, the thin portion is cleaved when the airbag is inflated, and the airbag is inflated from the cleaved portion.

  Flame treatment is performed on the surface of the core obtained by the molding. The flame treatment is performed in order to bring the polyolefin resin into an active state and improve the adhesion with an adhesive to be applied later. The flame treatment is preferably performed until the surface tension of the polyolefin resin core material is 36 to 60 mN / m, and more preferably 40 to 50 mN / m. When the surface tension is within the above range, it is possible to ensure good adhesion and wettability of the adhesive to the substrate surface. In order to make the surface tension within the above range, it can be appropriately adjusted depending on the type of gas to be burned, the gas flow rate, the distance from the flame outlet to the core material surface, the processing time, etc. is there. The measured value of the surface tension is a value measured according to JIS K 6768 (wetting tension test method).

  An adhesive described later is applied to the surface of the core material subjected to the flame treatment. As the application method, spray coating, airless spray coating, curtain flow coater coating, roll coater coating, brush coating, dip coating, and the like can be used. These coating methods are appropriately determined depending on the shape of the core material, etc. It is possible to select. In the present invention, since automobile interior parts usually have complicated shapes, air spray coating and airless spray coating are particularly suitable as coating methods that can handle these complex shapes. ing.

The amount of adhesive applied, by dry weight is preferably 4~60g / ^{m 2,} and still more preferably from 9~50g / ^{m 2.} When the amount is less than 4 g / m ² , the adhesion effect of the coated adhesive cannot be exhibited, and the adhesiveness when the temperature of the interior material rises tends to be unable to be secured. On the other hand, when the amount is more than 60 g / m ² , no further improvement in the adhesion effect can be expected, which tends to be economically disadvantageous, and also tends to cause cohesive peeling of the coating film due to stress due to curing shrinkage of the adhesive. .

  After the adhesive is applied, the surface of the adhesive is dried, and the adhesive surface is dried to such an extent that the urethane material can be injected later. As a method for drying, a method such as room temperature drying or forced drying can be used. In this invention, it is preferable to use forced drying especially from a viewpoint of production efficiency, and it is desirable to carry out as a drying condition in that case in the temperature range of 60-90 degreeC for 30 to 60 minutes. The adhesive can be transferred to the next step in a state where it is not completely dried, or can be transferred to the next step in a state where it is completely dried.

A dried core material having an adhesive surface is placed in a mold, and non-foamed urethane is injection-molded to form a urethane skin. RIM molding is employed as the injection molding method. As the mold used in the molding, any of conventionally used molds can be used, and the form can be appropriately changed depending on the shape of the interior material required. Moreover, when molding non-foamed urethane, it is possible to smoothly remove the release agent from the mold after molding by pre-coating a release agent inside the mold. As these release agents, any release agent conventionally used for in-mold molding can be used, and typical examples thereof include silicone and wax. The coating amount of the release agent is preferably in the range of 100 to 160 g / ^{m 2.} The injection amount of non-foamed urethane is preferably such an amount that the thickness is in the range of 0.5 to 3.0 mm from the core surface, and is in the range of 1.0 to 1.5 mm. Further preferred. When the thickness of the non-foamed urethane is thinner than 0.5 mm, the design of the interior part tends to be lowered. On the other hand, when it is thicker than 3.0 mm, it tends to inhibit the breakage of the surface of the interior part when the airbag is inflated, and further improvement in tactile function cannot be expected, which tends to be economically disadvantageous. It is in.

  In the present invention, it is possible to improve the aesthetics and tactile sensation of the interior parts by coating the surface of the non-foamed urethane obtained as described above. As a method for applying these paints, any of ordinary methods used when applying paints such as spray coating can be employed. About the application quantity of the said coating material, it can change suitably with the coating composition to be used, the performance calculated | required, etc.

  Furthermore, as a method of coating the paint, after applying a release agent to the inside of the mold for molding the non-foamed urethane, the paint is spray-coated in the mold, and the foam-free urethane is coated in the mold to which the paint is attached. Molding of non-foamed urethane and surface coloring can be simultaneously performed by a so-called in-mold coating method.

In the present invention, the conditions for RIM molding are that the mold clamping is 10 to 40 kg / cm ² , and the heating temperature in the mold is 40 to 70 ° C. This is particularly preferable from the viewpoint of ensuring.

  Subsequently, the coating material applied to the surface of the core resin, adhesive, non-foamed urethane, and interior material used in the present invention will be described below.

"Materials and adhesives for new agents used in the present invention"
"Material of core material"
The material of the core material in the present invention is a polyolefin resin from the viewpoint of durability, strength, and the like. As these polyolefin resins, for example, polyethylene, polypropylene, polyisobutylene, polyisoprene, or polybutadiene, or one of these chlorinated products, or a combination of two or more thereof can be used. It is also possible to use ethylene propylene rubber (EPM) and ethylene propylene rubber (EPDM) obtained by adding a small amount of a third component to EPM.

"Adhesive formulation"
The adhesive in the present invention contains a binder and a specific polyester polyol, and includes other solvents, additives and the like as necessary.

  As the binder, any resin used in adhesive applications can be used as the binder, and can be appropriately changed according to the material of the core material, required performance, and the like. As typical examples of these resins, acrylic resins, urethane resins, fluororesins, inorganic resins, silicone resins, epoxy resins, or a combination of two or more can be used. Particularly in the present invention, the use of an acrylic resin makes it possible to secure the adhesive force between the core material and the non-foamed urethane.

  As the acrylic resin, any acrylic resin usually used in adhesives and paints can be used. These acrylic resins can be obtained by polymerizing a polymerizable monomer by a known method. Typical examples of the monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , Pentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, α-chloroethyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) ) Acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, ethoxypropyl (meth) acrylate, etc. Styrene monomers such as styrene, methylstyrene, chlorostyrene, methoxystyrene; acrolein, diacetone (meth) acrylamide, formysterol, (meth) acryloxyalkylpropanal, diacetone (meth) acrylate, acetonyl ( Carbonyl group-containing ethylenic compounds such as (meth) acrylate, acetoacetoxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate-acetyl acetate, butanediol-1,4-acrylate-acetyl acrylate, vinyl ethyl ketone, vinyl isobutyl ketone Unsaturated monomer; carboxyl group-containing monomer such as (meth) acrylic acid, crotonic acid, itaconic acid, itaconic acid half ester, maleic acid, maleic acid half ester; 2-hydroxy Hydroxyl-containing monomers such as ethyl (meth) acrylate, 2 (3) -hydroxypropyl (meth) acrylate, 4-hydroxybutyl acrylate, mono (meth) acrylic acid ester of allyl alcohol polyhydric alcohol; (meth) acrylamide Amide group-containing monomers such as maleamide; 2-aminoethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, 3-aminopropyl (meth) acrylate, 2-butylaminoethyl (meth) acrylate, An amino group-containing monomer such as vinylpyridine; obtained by reaction of glycidyl (meth) acrylate, allyl glycidyl ether, an epoxy compound having two or more glycidyl groups and an ethylenically unsaturated monomer having an active hydrogen atom Epoxy group-containing monomers and oligomers 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloyloxy-1 , 2,2,6,6-pentamethylpiperidine, 4- (meth) acryloylamino-1,2,2,6,6-pentamethylpiperidine, 4-cyano-4- (meth) acryloylamino-2,2 , 6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) Acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (meth) acryl Light-stable monomers such as ylamino-2,2,6,6-tetramethylpiperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine; 2- [2′- Hydroxy-5 ′-(methacryloyloxymethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy-5 ′-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2′-hydroxy- 5 '-(methacryloyloxypropyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxyhexyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-3 ' -T-butyl-5 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2 -[2'-hydroxy-5'-t-butyl-3 '-(methacryloyloxyethyl) phenyl] -2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxyethyl) phenyl] -5 -Chloro-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-methoxy-2H-benzotriazole, 2- [2'-hydroxy-5'-(methacryloyloxy) Ethyl) phenyl] -5-cyano-2H-benzotriazole, 2- [2'-hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-t-butyl-2H-benzotriazole, 2- [2'- Hydroxy-5 '-(methacryloyloxyethyl) phenyl] -5-nitro-2H-benzotriazol UV-absorbing monomers such as N-methylol acrylamide having an N-methylol group, vinyl acetate, vinyl chloride, and further ethylene, butadiene, acrylonitrile, dialkyl fumarate, etc. Or it can be used in combination of two or more.

  The number average molecular weight of the acrylic resin obtained by the polymerization is preferably in the range of 1000 to 15000, and more preferably in the range of 1500 to 10,000. If the molecular weight is less than 1000, the viscosity of the adhesive will decrease significantly, causing sagging and cracking during coating, resulting in a decrease in the design of the interior material that is finally obtained, and partial adhesion of non-foamed urethane Tend to decrease. On the other hand, when the molecular weight is larger than 15000, the viscosity of the adhesive is remarkably increased, and it becomes difficult to ensure a good discharge state when coating the adhesive, and the adhesiveness of the non-foamed urethane tends to partially decrease. is there. Typical examples of these acrylic resins include U-Double 3300 (manufactured by Nippon Shokubai Co., Ltd., molecular weight Mn 9900, hydroxyl value 30) and Acryset 4230 (manufactured by Nippon Shokubai Co., Ltd., molecular weight Mn 1600, hydroxyl value 116). However, it is not limited to these.

  The blending amount of the acrylic resin is preferably 80 to 95% by mass and more preferably 85 to 95% by mass with respect to the total solid content of the adhesive. When the blending amount of the acrylic resin is less than 80% by mass, the adhesive effect of the adhesive is weakened, and the adhesion failure of the non-foamed urethane tends to occur. On the other hand, when it is more than 95% by mass, the application efficiency at the time of applying the adhesive is deteriorated, and the non-foamed urethane tends to cause poor adhesion partially.

  As the binder, in addition to acrylic resin, urethane resin, epoxy resin, silicone resin, and the like can be used, and the type, amount of addition, and the like can be changed as appropriate.

  The polyester polyol having the specific structure refers to a polyester polyol having a number average molecular weight of 400 to 700 having hydroxyl groups at both ends. Since the polyester polyol has hydroxyl groups at both ends, the effect of hydrogen bonding further enhances the adhesion to polyolefin resin and non-foamed urethane as the core material, ensuring adhesion in low or high temperature environments. It becomes possible to do. Moreover, it is more preferable to use the polyester polyol obtained by reacting a dialcohol having an aliphatic ring with a linear dicarboxylic acid. By using such a thing, the adhesive force of an adhesive agent can further be improved. Examples of the dialcohol having an aliphatic ring include, but are not limited to, 1,4, -cyclohexanediol, 1,2-cyclohexanediol, and cyclohexanedimethanol. Typical examples of the linear dicarboxylic acid include, but are not limited to, adipic acid, terephthalic acid, isophthalic acid, fumaric acid, sebacic acid, and dimer acid. As a method for producing the polyester polyol, any of methods for producing polyesters can be used.

  The polyester polyol must have a number average molecular weight of 400 to 700, preferably in the range of 400 to 500. The number average molecular weight can be measured by a general method, and examples thereof include a method using GPC. Those having an average molecular weight of less than 400 are difficult to obtain as a resin. On the other hand, when the molecular weight is larger than 700, the flexibility of the adhesive film is lowered, and when stress is generated in the core material due to a temperature change or the like, there is a tendency for poor adhesion between the core material and non-foamed urethane. Typical examples of these polyester polyols include, but are not limited to, FLEXOREZ188 (manufactured by KING INDUSTRY, molecular weight Mn460). In the present invention, from the viewpoint of adhesion to the core material and non-foamed urethane, the blending ratio of the polyester polyol is preferably in the range of acrylic resin: polyester polyol = 95: 5 to 85:15. When the addition amount of the urethane resin is less than the above range, the effect due to the addition of the polyester polyol tends not to be expected. On the other hand, when the addition amount of the polyester polyol increases beyond the above range, the adhesion between the core material and the urethane foam tends to decrease.

  As the solvent, any solvent used in adhesives or paints can be used. For example, aromatic hydrocarbons such as toluene and xylene: acetate esters such as ethyl acetate and butyl acetate Class: Ketones such as methyl ethyl ketone and methyl isobutyl ketone: Alcohols such as isopropyl alcohol and butyl alcohol: Furthermore, one or more selected from various aliphatic hydrocarbons, glycol ethers, water, etc. It can be used in combination.

  As the additive, any solvent used in adhesives or paints can be used, for example, an antifoaming agent, a leveling agent, an ultraviolet absorber, a film forming aid, a light stabilizer, Antibacterial agents, crosslinking accelerators, dispersants, suspending agents, wetting aids for ink solvents, etc. can be blended as necessary, and binders, color pigments, extender pigments, water absorbing fillers to be used, Depending on the solvent and the like, the type and amount of the additive can be changed.

  When an acrylic resin is used, an isocyanate resin or an epoxy resin can be used as a curing agent. In the case of blending these curing agents, for example, when isocyanates are used as the curing agent, it is preferable to mix in the range of OH / NCO = 0.5 to 1.5 equivalents.

"Non-foamed urethane"
Since the non-foamed urethane used in the present invention is formed by RIM molding as described above, it is possible to use a combination of polyol and isocyanate depending on the required properties of the urethane skin. Examples of polyols that can be used in the present invention include hydroxyl group-containing compounds such as propylene glycol, diethylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol and sucrose, or amino group-containing compounds such as ethylenediamine and diaminotoluene, ethylene oxide, propylene oxide and the like. Typical examples include polyether polyols containing 2 to 6 hydroxyl groups in the molecule to which the alkylene oxide is added and having an average hydroxyl equivalent weight of 100 to 3000, or polymer polyols obtained by addition polymerization of these polyether polyols with vinyl compounds. It is mentioned as a thing. Polyester polyols that can be obtained from polycarboxylic acids and low molecular weight hydroxyl group-containing compounds, polycarbonate polyols obtained by ring-opening polymerization of caprolactone, amination of hydroxyl groups of polyether polyols, or hydrolysis of isocyanate polyol prepolymers of polyether polyols It is also possible to use a polyether polyamine having an average active hydrogen equivalent of 100 to 3000.

  Polyisocyanates include diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, urethane modified, allophanate modified, carbodiimide modified, isocyanurate modified polyisocyanate, these A typical example is a mixture of the above.

In the present invention, the above polyol and isocyanate can be used in combination depending on the performance of the automobile interior part finally obtained as described above, but these combinations are finally obtained. The tensile strength of the non-foamed urethane skin is preferably in the range of 15 to 45 kgf / cm ² . When the tensile strength is less than 15 kgf / cm ² , the urethane skin is cleaved at a place other than the predetermined location, and the airbag tends to be difficult to deploy. On the other hand, when it is higher than 45 kgf / cm ² , the airbag tends to be inhibited from being deployed. In addition, the said tensile strength points out the numerical value at the time of measuring based on JISK6301 (tensile test). In addition, the said numerical value is a measured value when the distance between marked lines is 20 mm and a pulling speed is 500 mm / min using a No. 2 test piece.

"paint"
As the paint used in the present invention, any paint used as an overcoat for automobile interior parts can be used. As the resin used in the paint, for example, one or more of acrylic resin, urethane resin, fluororesin, acrylic silicone resin, silicone resin and the like are appropriately selected based on the performance required for the interior parts. It is possible. Solvents, additives, pigments, etc. that are commonly used in paints can be used without any particular restrictions. The type selection and addition amount are based on the performance required for interior parts. It is possible to select as appropriate.

  When the top coating is applied by the in-mold coating, it is preferable that the coating does not contain a solvent. If a solvent is contained, the solvent will rapidly evaporate due to the clamping pressure and heat applied to the mold, resulting in coating failure such as cracks on the coating surface, and the final design of the interior parts that will be obtained Tend to decrease.

"Automobile interior parts"
The automobile interior part obtained by the method as described above can be used to manufacture an airbag device. That is, after the urethane skin is formed, or on the urethane skin, an automobile interior part having a coating film formed on the surface is used as an outer part of an airbag device, and an inner is incorporated therein. Next, the outer incorporating the inner is fixed to a vibration welding jig arranged vertically, and one side of the resin whose surfaces are combined is vibrated in a range of 100 to 250 Hz by the action of a magnet, and the inner and outer contact is caused by the vibration. After the inner and outer are welded by the frictional heat generated in the part, the airbag is assembled to complete the airbag device. The above operation can be performed using, for example, a Branson 824H vibration welding machine.

  Hereinafter, the present invention will be described in more detail with reference to examples. Needless to say, the following examples do not limit the scope of the present invention.

The core material, adhesive, non-foamed urethane, and top coating used in this example were obtained for the following purposes. The molecular weight of the resin used in this example was measured using the following measuring equipment.
-Manufacturer name: Tosoh-Model: HLC-8220GPC
Column: TSKgel G5000-2000
・ Eluent: THF
・ Flow rate: 1 ml / min

"Core"
Mold for manufacturing instrument panels using a composite material (PP-C) (trade name: MRC314, manufactured by Nippon Polypro Co., Ltd.) with additives such as talc added to polypropylene. The core material is formed by injection molding (molding temperature: 35 ° C., resin temperature: 230 ° C., molding pressure: 80 kg / cm ² , injection time: 8 to 10 seconds) on a projection for forming a door-predetermined portion) Obtained.

"adhesive"
(Adhesive 1)
40.6 parts by mass of acrylic resin (trade name: Acryset 4230, manufactured by Nippon Shokubai Co., Ltd., molecular weight Mn 1600, NV 72%, hydroxyl value 116), acrylic resin (trade name: U Double 3300, manufactured by Nippon Shokubai Co., Ltd., molecular weight Mn 9900, NV 47% , Hydroxyl value 30) 41.4 parts by mass, leveling agent (trade name: Disparon LC-915, manufactured by Enomoto Kasei Co., Ltd.) 1.0 part by mass, hindered amine light stabilizer (trade name: Sandbar S3212, manufactured by Clariant) 2 0.0 parts by mass, 5.0 parts by mass of butyl acetate, 7.0 parts by mass of methoxybutyl acetate, 3.0 parts by mass of xylene, and the above components were mixed with a desktop disper to prepare adhesive 1. When applying the adhesive, isocyanate (trade name: Dismodule N75, manufactured by Sumitomo Bayer Co., Ltd.) with respect to 100 parts by weight of the adhesive. NCO% 17) 26 parts by mass, were mixed, it was used in the coating (OH / NCO = 1.0).

(Adhesive 2)
Polyester polyol having a hydroxyl group at both ends (trade name: FREXOREZ188, manufactured by KING INDUSTRY, number average molecular weight Mn460, NV100%, hydroxyl value 230) is 5.0 parts by mass with respect to 95.0 parts by mass of the adhesive 1 Addition to prepare adhesive 2, and when applying the adhesive, 30 mass of isocyanate (trade name: Dismodule N75, manufactured by Sumitomo Bayer, NCO% 17) with respect to the adhesive 2: 100 parts by mass After mixing and mixing parts, it was used for coating (OH / NCO = 1.0).

(Adhesive 3)
5.6 parts by mass of polyester polyol (trade name: FREXOREZ171-90, manufactured by KING INDUSTRY, number average molecular weight Mn1000, NV90%, hydroxyl value 122) is added to 95.0 parts by mass of the adhesive 1. When preparing the adhesive 3 and applying the adhesive, 28.isocyanate (trade name: Dismodule N75, manufactured by Sumitomo Bayer, NV 75%, NCO% 17) with respect to 100 parts by mass of the adhesive 3:28. After 0 parts by mass and mixing, it was used for coating (OH / NCO = 1.0).

(Adhesive 4)
Polyester polyol (trade name: Barnock J505, manufactured by Dainippon Ink Co., Ltd., number average molecular weight Mn1000, NV100%, hydroxyl value 55) is added to 5.0 parts by mass of the adhesive 1, 95.0 parts by mass. When preparing the adhesive 4 and applying the adhesive, the isocyanate (trade name: Dismodule N75, manufactured by Sumitomo Bayer, NV 75%, NCO% 17) is 26.100 parts by mass of the adhesive 4: 100 parts by mass. After 0 parts by mass and mixing, it was used for coating (OH / NCO = 1.0).

"Non-foamed urethane"
Polyol (trade name: SBU polyol W305, manufactured by Sumika Bayer Urethane Co., Ltd.) and isocyanate (trade name: SBU isocyanate 0418, manufactured by Sumika Bayer Urethane Co., Ltd.) were used.

"Topcoat"
An acrylic urethane-based paint (trade name: Planit IMC-NI, manufactured by Dainippon Paint Co., Ltd.) was used.

(Manufacture of automotive interior parts)
Using the manufactured core material, automobile interior parts were manufactured under the following conditions, and the effects of the present invention were confirmed. Each operation was carried out by the following method.

(Flame treatment)
The core material was flame-treated by treating LP gas with a distance from the flame outlet to the core material of 100 mm for 30 seconds. In addition, the average value which measured the surface tension of five places of the base material which performed the flame treatment by the method based on JISK6768 was shown. In addition, the surface tension of the comparative example 1 which has not performed the flame treatment was 33 mN / m. The results are shown in Table 1.

(Applying adhesive)
Based on the following table | surface, the adhesive agent was apply | coated with respect to the core material which performed the flame processing, or the core material which has not performed the flame processing. Based on the following table | surface, each adhesive agent was apply | coated so that dry weight might be set to 28 g / m < ² > with an air spray coating machine, and after applying an adhesive agent, it forcedly dried at 80 degreeC * 30 minutes.

(RIM molding of non-foamed urethane)
Based on the following table, using a mold in which 150 g / m ² of a fluorine-based mold release agent is applied in advance as a release agent to a core material to which an adhesive surface has been applied or a core material to which an adhesive has not been applied, RIM molding was performed at a mixing ratio of the polyol and isocyanate of 100: 20. As conditions for RIM molding, the injection pressure is 150 kg / cm ² , the clamping pressure is 10 kg / cm ² , and the mold temperature is 60 ° C. Moreover, the tensile strength of the non-foamed urethane produced under the above conditions was 25 kgf / cm ² or more as a result of measurement by the method described above.

(Coating of top coat)
After RIM molding of the non-foamed urethane, the top coating was applied with an air spray coater so that the dry mass was 20 g / m ^2, and die molding was performed.

(Manufacturing of airbags for automobile interior parts)
The member coated with the above-mentioned top coat was used as the outer, and the outer incorporating the inner was fixed to a vibration welding jig (manufactured by Branson), and the inner and outer were fused under a pressure condition of 5.4 MPa. Thereafter, an airbag was incorporated to manufacture an airbag device.

<Evaluation test>
The following evaluation tests were performed on the manufactured automobile interior parts. The results of each evaluation test are as shown in Table 1 below.

<Adhesion>
The adhesion test was performed by a method based on JIS K6829 (tensile test).

<Initial adhesion>
The initial adhesion of the outer parts of the automobile interior parts produced by the above method was measured.

<Adhesion at high temperatures>
The manufactured automobile interior part was held in an environment of 80 ° C. × 4 hours, and the adhesion was measured immediately after the heat treatment described on the left.

<Adhesion at low temperatures>
The manufactured automobile interior part was held in an environment of −40 ° C. × 4 hours, and adhesion was measured immediately after the low-temperature treatment described on the left.

  It measured based on the said JISK6829, and in the adhesiveness of polyolefin resin core material and non-foamed urethane, the adhesive strength until non-foamed urethane fracture | rupture was observed visually. The evaluation criteria are as follows.

○: The state in which the non-foamed urethane is broken ×: The separation at the interface between the polyolefin resin core and the adhesive, or the separation at the interface between the adhesive and the non-foamed urethane, or the state in which the adhesive has undergone cohesive separation

<Airbag tearability>
The airbag of the automobile interior part incorporating the manufactured airbag was actually actuated, and the outer tearing state was visually observed. The evaluation criteria are as follows.

○: No trouble such as peeling of non-foamed urethane occurs, and there is no hindrance to the operation of the airbag. △: Partial peeling of non-foamed urethane occurs at the opening of the airbag. Is a state where there is no problem and there is no problem in practical use. ×: The non-foamed urethane is largely peeled around the part other than the cleavage part of the airbag or at the cleavage part, and there is a practical problem.

  As a result of the above examination, Example 1 which is within the scope of the present invention has good initial adhesion and adhesion at high temperatures and low temperatures, and also shows good results for the tearability of the airbag.

  On the other hand, in Comparative Examples 1 to 5, which are outside the scope of the present invention, it is apparent that the performance is not exhibited as compared with the Examples in terms of adhesion and airbag tearability.

The automobile interior part according to the present invention can be used for the manufacture of an airbag device as described above, and as a function thereof, the airbag can be stably deployed even in a high temperature or low temperature environment. Contributes to ensuring safety. Moreover, it has the function as an interior material excellent in tactile sensation and design by the urethane skin or colored coating layer applied on the surface.

Claims (5)

A step of performing flame treatment on a core material made of polyolefin resin;
A step of applying an adhesive containing a binder and a polyester polyol having a number average molecular weight of 400 to 700 having hydroxyl groups at both ends to the flame-treated core material surface;
The core material coated with the adhesive is placed in a mold, and a non-foamed urethane reaction liquid is injected into the surface coated with the adhesive to react in the mold and molded integrally with the core material. When,
The manufacturing method of the interior component for motor vehicles characterized by having.   The manufacturing method of the interior component for motor vehicles of Claim 1 from which surface tension of the core material containing polyolefin resin becomes 36-60 mN / m by the said flame treatment.   The method for manufacturing an automobile interior part according to claim 1, wherein the binder is an acrylic resin. A core material having a planned door portion for airbag expansion made of polyolefin resin;
A skin material made of non-foamed urethane,
An adhesive layer containing a binder and a polyester polyol having a number average molecular weight of 400 to 700 having a hydroxyl group at both ends between the core material and the skin material;
An automotive interior material characterized by comprising:   The automobile interior material according to claim 4, wherein the binder is an acrylic resin.