JP5189018B2 - Slush molding resin powder composition and molded product - Google Patents

Description

  The present invention relates to a resin powder composition for slush molding that is excellent in low temperature meltability and deformation resistance under high temperature use environments.

A resin composition for slush molding containing a radically polymerizable unsaturated group-containing compound having long-term durability under ultraviolet irradiation and high temperature is known. (For example, Patent Documents 1 and 2)

JP 2000-103956 A JP 2001-192549 A

It has been found that a resin molded product made of a good-melting resin that can be molded at low temperature during slush molding has a low heat softening temperature, deformation in a high temperature use environment, and adhesion between molded products.
For this reason, if the heat softening temperature of the polyurethane resin used for slush molding is increased for the purpose of improving deformation resistance at high temperatures, the deformation resistance at high temperatures is improved, but the meltability is not sufficient during molding. The quality of the molded product may deteriorate.
The problem to be solved by the present invention is to provide a resin powder composition for slush molding in which a resin molded product is excellent in meltability and deformation resistance under a high temperature use environment.

As a result of intensive studies, the present inventors have completed the present invention.
The present invention comprises a radically polymerizable unsaturated group-containing compound (A) mainly comprising a thermoplastic polyurethane resin powder (D) and containing 2 to 10 radically polymerizable unsaturated groups (a) in one molecule and 1 minute. The resin powder composition for slush molding (S) is characterized by containing an organic peroxide (B) having a temperature of 170 ° C. to 200 ° C. when the number of molecules decomposes into ½.

The resin molded product (T) obtained by slush molding from the slush molding resin powder composition (S) of the present invention is excellent in meltability and resistance to deformation under a high temperature use environment.

The radically polymerizable unsaturated group-containing compound (A) contains 2 to 10 radically polymerizable unsaturated groups (a) in one molecule. Examples of the radically polymerizable unsaturated group (a) include (meth) acryloyl group, (meth) allyl group, vinyl group, propenyl group, etc., (meth) acryloyl group and (meth) allyl group are preferable.
As the radically polymerizable unsaturated group-containing compound (A) used in the present invention, an ester of (meth) acrylic acid and a polyhydric alcohol [for example, ethylene glycol (meth) acrylate, trimethylolpropane tri (meth) acrylate, Pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate]; esters of (meth) allyl alcohol and polyvalent carboxylic acids [for example, diallyl phthalate, trimellitic acid triallyl ester, etc.]; Poly (meth) allyl ether [for example, pentaerythritol tri (meth) allyl ether, etc.]; Polyhydric alcohol polyvinyl ether [for example, ethylene glycol divinyl ether]; Polyhydric alcohol polypropenyl ether [for example, Etc. Chi glycol dipropionate propenyl ether], esters of maleic acid and diols [such as ethylene di maleate]; esters of itaconic acid and a diol [for example, ethylene di-itaconate] and the like. Among these, preferred are esters of (meth) acrylic acid and polyhydric alcohols, esters of allyl alcohol and polyhydric carboxylic acids, and polyallyl ethers of polyhydric alcohols in terms of radical polymerization rate. Particularly preferred are trimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate and dipentaerythritol penta (meth) acrylate. In the present invention, (meth) acrylate refers to acrylate and methacrylate.

The number of unsaturated groups per molecule of the radically polymerizable unsaturated group-containing compound (A) is 2 to 10, preferably 3 to 6. When the number of functional groups is less than 2, the amount of crosslinking is small, and the heat softening temperature does not increase sufficiently after irradiation with ultraviolet rays and / or electron beams. It becomes.

The radically polymerizable unsaturated group-containing compound (A) is preferably contained in an amount of 2 to 8% by weight, more preferably 3 to 5% by weight, based on the weight of the thermoplastic polyurethane resin powder (D).

The organic peroxide (B) is a compound having a temperature at which the number of molecules decomposes in one minute to ½ (hereinafter referred to as half-life temperature) is 170 ° C. to 200 ° C. The temperature is preferably 180 ° C to 190 ° C.
In slush molding, usually, the molding temperature is 210 to 250 ° C. and the molding time is about 1 minute, so the organic peroxide (B) as described above is used.
In (B), when the half-life temperature is less than 170 ° C., the radically polymerizable unsaturated group-containing compound (A) is cross-linked before the slush molding resin powder composition (S) is sufficiently melted, and the meltability is reduced. It can get worse. Moreover, when it exceeds 200 degreeC, a radically polymerizable unsaturated group containing compound (A) may not fully bridge | crosslink during a shaping | molding time, and a heat softening temperature may not rise.

Examples of the organic peroxide (B) used in the present invention include dialkyl peroxides [for example, dicumyl peroxide, 2,2,5-dimethyl-2,5-di (t-butylperoxy) hexane, D- t-hexyl peroxide, D-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 and the like]; peroxyester [eg, t-hexylperoxyisopropyl Monocarbonate, t-butyloxylaurate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanate, etc.]; Hydroperoxide [eg cumene hydroperoxide, P-menthane hydroperoxide, 1,1,3,3-tetra Peroxyketals [eg, 1,1-di (t-hexylperoxy) cyclohexane, 2,2-di-butylperoxyhexane, etc.]; ketone peroxides; peroxyketals, etc. Can be mentioned. From these half-life temperatures, preferred are dicumyl peroxide (half-life temperature: 175.2 ° C.), 2,2,5-dimethyl-2,5-di (t-butylperoxy) hexane (half-life). Phase temperature: 179.8 ° C), Dt-hexyl peroxide (half-life temperature: 185.9 ° C), and Dt-butyl peroxide (half-life temperature: 194.3 ° C).

The weight ratio of the radical polymerizable unsaturated group-containing compound (A) and the organic peroxide (B) contained in the slush molding resin powder composition (S) of the present invention is preferably 1: (0.01 To 0.17), more preferably 1: (0.05 to 0.1). By making the weight ratio of the radical-polymerizable unsaturated group-containing compound (A) and the organic peroxide (B) within the above range, it is possible to reduce the meltability of the decomposition product of the organic peroxide (B) during slush molding. The crosslinking reaction of the radically polymerizable unsaturated group (a) can be advanced without deteriorating. By the crosslinking reaction of the radically polymerizable unsaturated group (a), the heat softening temperature rises, and the deformation resistance under a high temperature use environment can be improved.

The method of adding and mixing the radically polymerizable unsaturated group-containing compound (A) and the organic peroxide (B) to the polyurethane resin before molding of the present invention is not particularly limited. A method of adding and mixing in the step of mixing with a plasticizer, a pigment, a stabilizer and the like added to the polyurethane resin as necessary after the production can be mentioned. The mixing temperature of the radically polymerizable unsaturated group-containing compound (A) and the organic peroxide (B) is preferably 70 to 85 ° C, more preferably 74 to 82 ° C.

As the mixing device used for mixing, a known powder mixing device can be used, and any of a container rotation type mixer, a fixed container type mixer, and a fluid motion type mixer can be used. For example, high-speed fluidity mixers, double-shaft paddle-type mixers, high-speed shear mixers (Hensiel mixer (registered trademark), etc.), low-speed mixers (planetary mixers, etc.) and conical screw mixers A method of dry blending using a machine [Nauter Mixer (registered trademark), etc.] is well known. Among these methods, it is preferable to use a double-shaft paddle type mixer, a low speed mixing device (planetary mixer or the like), a conical screw mixer [Nauter mixer (registered trademark, hereinafter omitted)] or the like.

The thermoplastic polyurethane resin powder (D) is made of a thermoplastic polyurethane resin. The thermoplastic polyurethane resin is a resin composed of a high molecular polyol, a polyisocyanate, and a low molecular diol, a low molecular diamine, if necessary. As the polymer polyol, polyester polyol is preferable. As polyisocyanate, alicyclic diisocyanate, aliphatic diisocyanate, and a mixture of both are preferable.

In the present invention, examples of the thermoplastic polyurethane resin powder used for molding include those obtained by the following production method. (1) It has a urethane bond and a urea bond, and is produced by a method of reacting an isocyanate group-terminated urethane prepolymer with a blocked chain extender (for example, a ketimine compound) in the presence of water and a dispersion stabilizer. Specifically, for example, those described in JP-A-8-120041 can be used. (2) produced by reacting a urethane prepolymer having a urethane bond and a urea bond with a chain extender (for example, diamine and / or diol) in the presence of an organic solvent in which the urethane prepolymer does not dissolve and a dispersion stabilizer. Things. Specifically, for example, those described in JP-A-4-202331 can be used. (3) A mass of a thermoplastic polyurethane resin is obtained by reacting a diisocyanate, a high molecular diol, and a chain extender (low molecular diol, low molecular diamine) as necessary. Then, it is manufactured by a method of pulverization (for example, freeze pulverization, a method of cutting through pores in a molten state).

The volume average particle diameter of the thermoplastic polyurethane resin powder (D) is preferably 10 to 500 μm, more preferably 70 to 300 μm.

The resin powder for slush molding of the present invention can be molded into a resin molded body by a slush molding method.
As the slush molding method, for example, both the box containing the resin powder of the present invention and a heated mold are vibrated and rotated, and after the resin powder is melted and flowed in the mold, the molten resin is cooled and solidified, A method for producing a resin molded body (skin etc.) is included.

The heat softening temperature of the polyurethane skin (T) is preferably 135 to 170 ° C., more preferably 140 to 170 ° C., and particularly preferably 145 to 170 ° C., from the viewpoint of long-term durability under a high temperature use environment.

The resin molded product of the present invention is suitably used for automobile interior materials such as instrument panels and door trims.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to this. In the following, “parts” represents parts by weight, and “%” represents% by weight.

Production Example 1
Production of prepolymer solution In a reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube, polybutylene adipate (497.9 parts) having a number average molecular weight (hereinafter referred to as Mn) of 1000 and poly having a Mn of 900 Hexamethylene isophthalate (124.5 parts), pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] [manufactured by Ciba Specialty Chemicals, Inc .; Irganox 1010] (1.12 parts), kaolin (90.7 parts) having a volume average particle size of 9.2 μm were charged, and after substitution with nitrogen, the mixture was heated to 110 ° C. with stirring and melted, and cooled to 60 ° C. Subsequently, 1-octanol (9.7 parts), hexamethylene diisocyanate (145.0 parts) tetrahydrofuran (125 parts), 2- (2H-benzotriazol-2-yl) -6- (linear and side chain dodecyl) ) -4-methylphenol [manufactured by Ciba Specialty Chemicals Co., Ltd .; Tinuvin 571] (2.22 parts) was added and reacted at 85 ° C. for 6 hours to obtain a prepolymer solution (D). The NCO content of (D) was 1.35%. Polycarbodiimide derived from tetramethylxylylene diisocyanate [Mn 15,000, terminal group: methoxy group, property: 70% methyl ethyl ketone (hereinafter referred to as MEK) solution, manufactured by Nisshinbo Co., Ltd .; Carbolite V-09B] (2.15) Part) and reacted at 85 ° C. for 6 hours to obtain a prepolymer solution. The NCO content of the prepolymer solution was 1.30%.

Production Example 2
Production of MEK (methyl ethyl ketone) ketimine product of diamine Hexamethylene diamine and excess MEK (4 times molar amount with respect to diamine) were refluxed at 80 ° C. for 24 hours, and the generated water was removed out of the system. Thereafter, unreacted MEK was removed under reduced pressure to obtain a MEK ketiminate.

Production Example 3
The prepolymer solution (C1) (100 parts) obtained in Production Example 1 and the MEK ketimine compound (3.6 parts) obtained in Production Example 2 were charged into a reaction vessel for producing a thermoplastic polyurethane resin powder. 340 parts by weight of an aqueous solution in which a dispersant containing Na salt of a copolymer of isobutylene and maleic acid (Sansper Chemical PS-8 manufactured by Sanyo Chemical Industry Co., Ltd.) (1.3 parts by weight) was added, It was mixed for 1 minute at a rotation speed of 9000 rpm using an Ultra Disperser manufactured by Co., Ltd. This mixture was transferred to a reaction vessel equipped with a thermometer, a stirrer and a nitrogen blowing tube, purged with nitrogen, and then reacted at 50 ° C. for 10 hours with stirring. After completion of the reaction, filtration and drying were performed to produce a thermoplastic polyurethane resin powder (D1). Mn of (D1) was 25,000, the volume average particle size was 146 μm, and the glass transition temperature was −35 ° C.

Production Example 1 of Slush Molding Resin Powder Composition
In a 100 L Nauta mixer, thermoplastic polyurethane resin powder (D1) (100 parts), aromatic condensed phosphate ester (reaction product of trichlorophosphoric acid, bisphenol A and phenol) [Daihachi Chemical Co., Ltd .; CR-741] (6.0 parts), radically polymerizable unsaturated group-containing compound dipentaerythritol pentaacrylate (A1) [manufactured by Sanyo Chemical Industries, Ltd .; Neomer DA600] (3.9 parts), organic peroxide D-t-butyl peroxide (B1) (half-life temperature: 185.9 ° C.) [manufactured by NOF Corporation; Perbutyl D] (0.4 parts), light stabilizer bis (1,2,2) , 6,6-pentamethyl-4-piperidyl) sebacate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate (mixture) [trade name: TINUVIN 76 , Ciba] to give the 2 hours impregnated resin powder (0.27 parts) in turned by 70 ° C. The (E1). Two hours after impregnation, dimethylpolysiloxane (made by Nippon Unicar Co., Ltd .; Kei L45-1000) (0.1 part), carboxyl-modified silicon [made by Shin-Etsu Chemical Co., Ltd .; X-22-3710] (0.1 part) was added, mixed for 1 hour, and then cooled to room temperature. Finally, an antiblocking agent cross-linked polymethylmethacrylate [Gantz Kasei Co., Ltd .; Ganzpearl PM-030S] (0.3 parts) was added and mixed to obtain a slush molding resin powder composition (S1). The volume average particle diameter of (S1) was 150 μm.
The weight ratio of (A) :( B) was 1: 0.10, and the content of (A) relative to (D) was 3.9% by weight.

Example 2
In Example 1, a slush molding resin powder composition (S2) was obtained in the same manner as in Example 1 except that (A1) 3.1 parts was used instead of (A1) 3.9 parts. The volume average particle diameter of (S2) was 149 μm.
The weight ratio of (A) :( B) was 1: 0.13, and the content of (A) with respect to (D) was 3.1% by weight.

Example 3
Example 1 is the same as Example 1 except that 3.9 parts of (A1) is replaced by 3.9 parts of trimethylolpropane triacrylate [manufactured by Sanyo Chemical Industries, Ltd .; Neomer TA300] (A2). Thus, a slush molding resin powder composition (S3) was obtained. The volume average particle diameter of (S3) was 149 μm.
The weight ratio of (A) :( B) was 1: 0.10, and the content of (A) relative to (D) was 3.9% by weight.

Example 4
In Example 1, instead of 3.9 parts of (A1), a slush molding resin powder composition (S4) was prepared in the same manner as in Example 1 except that 3.9 parts of tripentaerythritol pentaacrylate (A3) was used. Obtained. The volume average particle diameter of (S4) was 150 μm.
The weight ratio of (A) :( B) was 1: 0.10, and the content of (A) relative to (D) was 3.9% by weight.

Example 5
In Example 1, a slush molding resin powder composition (S5) was obtained in the same manner as in Example 1 except that 3.9 parts of (A1) was used instead of 3.9 parts of (A1). The volume average particle diameter of (S5) was 151 μm.
The weight ratio of (A) :( B) was 1: 0.08, and the content of (A) with respect to (D) was 4.9% by weight.

Example 6
In Example 1, a slush molding resin powder composition (S6) was obtained in the same manner as in Example 1 except that 0.2 part of (B1) was used instead of 0.4 part of (B1). The volume average particle diameter of (S6) was 150 μm.
The weight ratio of (A) :( B) was 1: 0.05, and the content of (A) relative to (D) was 3.9% by weight.

Example 7
In Example 1, a slush molding resin powder composition (S7) was obtained in the same manner as in Example 1 except that 0.7 part of (B1) was used instead of 0.4 part of (B1). The volume average particle diameter of (S7) was 150 μm.
The weight ratio of (A) :( B) was 1: 0.18, and the content of (A) relative to (D) was 3.9% by weight.

Example 8
In Example 1, instead of 0.4 part of (B1), dicumyl peroxide (B2) (half-life temperature: 175.2 ° C.) [manufactured by NOF Corporation; Park Mill D] (0.4 part The resin powder composition for slush molding (S8) was obtained in the same manner as in Example 1 except that. The volume average particle diameter of (S8) was 151 μm.
The weight ratio of (A) :( B) was 1: 0.10, and the content of (A) relative to (D) was 3.9% by weight.

Example 9
In Example 1, instead of 0.4 part of (B1), 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3 (B3) (half-life temperature: 194.3 ° C.) A resin powder composition for slush molding (S9) was obtained in the same manner as in Example 1 except that it was made by [Nippon Yushi Co., Ltd .; Perhexyl 25B-40] (0.4 parts). The volume average particle diameter of (S9) was 150 μm.
The weight ratio of (A) :( B) was 1: 0.10, and the content of (A) relative to (D) was 3.9% by weight.

Comparative Example 1
In Example 1, a slush molding resin powder composition (S10) was obtained in the same manner as in Example 1 except that (B1) was changed to 0.4 part instead of (B1) 0.4 part. The volume average particle diameter of (S10) was 151 μm.
The weight ratio of (A) :( B) was 1: 0, and the content of (A) relative to (D) was 3.9% by weight.

Comparative Example 2
In Example 1, instead of 0.4 part of (B1), t-butyloxylaurate (B4) (half-life temperature: 159.4 ° C.) [manufactured by NOF Corporation; Perbutyl L] (0. A resin powder composition for slush molding (S11) was obtained in the same manner as in Example 1 except that the amount was 4 parts). The volume average particle diameter of (S11) was 149 μm.
The weight ratio of (A) :( B) was 1: 0.10, and the content of (A) relative to (D) was 3.9% by weight.

Comparative Example 3
In Example 1, instead of 0.4 parts of (B1), cumene hydroperoxide (B5) (half-life temperature: 232.5 ° C.) [manufactured by NOF Corporation; Park Mill H] (0.4 parts The resin powder composition for slush molding (S12) was obtained in the same manner as in Example 1 except that. The volume average particle diameter of (S12) was 152 μm.
The weight ratio of (A) :( B) was 1: 0.10, and the content of (A) relative to (D) was 3.9% by weight.

Using the slush molding resin powder compositions (S1) to (S9) of Examples 1 to 8 and the slash molding resin powder compositions (S10) to (S12) of Comparative Examples 1 to 3, the following is shown. The skin was molded by the method, and the backside meltability was confirmed, the heat softening temperature was measured, the heat distortion test and the heat adhesion test were performed.
The results are shown in Table 1.

<Creation of epidermis>
For the purpose of low-temperature molding, a Ni electric mold having a wrinkle pattern that has been heated to 230 ° C. in advance is filled with a resin powder composition for slush molding, and after 10 seconds, the excess powder resin powder composition is discharged. After further heating at 210 ° C. for 90 seconds, water cooling was performed to prepare a skin (thickness 1 mm). Evaluation of the backside meltability of this molded skin, measurement of heat softening temperature, and heat resistance test were performed.

<Backside meltability>
The meltability of the back surface center part of the molded skin is evaluated according to the following criteria.
5: Uniform and glossy.
4: There is a partially unmelted powder, but it is glossy.
3: There are irregularities on the entire back surface and there is no gloss. There are no pinholes penetrating the surface.
2: There are irregularities in the form of powder on the entire back surface, and there are no pinholes penetrating the surface.
1: The powder does not melt and does not become a molded product.

<Method for measuring thermal softening temperature>
Equipment: Thermomechanical analyzer TMA / SS6100
Data processing device EXSTAR6000 [made by SII Nanotechnology Co., Ltd.]
Measurement conditions: Measurement temperature range 25-250 ° C., heating rate 5 ° C./min, load 5 g, needle diameter 0.
5 mm.
Analysis method: In the TMA chart, the intersection of the tangents of the TMA curve is obtained according to the method of “JIS K7121-1987, p.

<Deformation resistance test>
The molded skin was treated in a circulating dryer at 130 ° C. for 400 hours. After the test, the skin was confirmed for fading and gloss.

Evaluation criteria The faded skin samples were directly visually observed and evaluated according to the following criteria.
◯: No discoloration Δ: Discoloration ×: Remarkably discolored gloss gloss meter (Portable gloss meter GMX-202: manufactured by Murakami Color Research Laboratory) was used to measure the gloss. The higher the gloss value, the glossier. The molded skin gloss of the slush molding resin powder compositions (S1) to (S11) before the heat resistance test was 1.0.

<Thermal bonding test>
Two molded skins were stacked and treated at 130 ° C. for 100 hours in a circulating dryer. After the test, it was confirmed whether or not the epidermis was adhered.

Evaluation Criteria The two skin samples superposed on each other were directly visually observed and evaluated according to the following criteria.
○: No adhesion ×: With adhesion

It can be seen that Examples 1 to 9 of the present invention have no problem with the backside meltability and that the heat softening temperature is high, so that the deformation resistance and the thermal adhesiveness are also improved.
Since Comparative Example 1 does not contain the organic peroxide (B), there is no problem with the backside meltability, but it can be seen that the thermal softening temperature is low and the deformation resistance and thermal adhesion are poor.
In Comparative Example 2, since the half-life temperature of the organic peroxide (B) is 170 ° C. or lower, the backside meltability is poor, but the heat softening temperature is high, so that the deformation resistance and the thermal adhesiveness are also improved. I understand that.
In Comparative Example 3, since the half-life temperature of the organic peroxide (B) is 200 ° C. or higher, the backside meltability is not a problem, but it can be seen that the thermal softening temperature is low and the deformation resistance and thermal adhesiveness are poor. .

The skin formed from the resin powder composition for slush molding of the present invention is suitably used as an automobile interior material, for example, an instrument panel or a door trim.

Claims (5)

A radically polymerizable unsaturated group-containing compound (A) containing 2 to 10 radically polymerizable unsaturated groups (a) in one molecule, mainly composed of thermoplastic polyurethane resin powder (D), and decomposed in 1 minute A resin powder composition for slush molding (S), comprising an organic peroxide (B) having a temperature at which the number of molecules becomes ½ is 170 ° C to 200 ° C. The resin powder composition for slush molding according to claim 1, wherein the radically polymerizable unsaturated group (a) is at least one group selected from the group consisting of a (meth) acryloyl group and a (meth) allyl group. ). The resin powder composition for slush molding according to claim 1 or 2, wherein the weight ratio of the radical polymerizable unsaturated group-containing compound (A) and the organic peroxide (B) is 1: (0.01 to 0.17). Object (S). The slush molding resin according to any one of claims 1 to 3, wherein the radically polymerizable unsaturated group-containing compound (A) is contained in an amount of 2 to 8% by weight based on the weight of the thermoplastic polyurethane resin powder (D). Powder composition (S). A resin molded product (T) obtained by slush molding the slush molding resin powder composition (S) according to any one of claims 1 to 4.