JP4290509B2 - In-mold coated molded body and method for producing the same - Google Patents

Description

  The present invention relates to an in-mold coated molded body and a method for producing the same, and more specifically, obtained by molding a thermoplastic resin material in a mold by an injection molding method, an injection compression molding method, an injection press molding method, or the like. An in-mold coating material is injected between the surface of the molding and the mold cavity surface, and this coating material is cured in the mold to produce an integrally molded product in which the coating material adheres to the surface of the resin molding. The present invention relates to an in-mold coating molded body obtained by a so-called in-mold coating forming method (in-mold coating method), and a method for manufacturing the same.

  Paint is applied to the surface of molded products for the purpose of adding added value such as decorativeness to resin molded products used in automobiles, home appliances, building materials, etc., or increasing the weather resistance and extending the product life. This has been done widely. As such a coating method, spray coating is generally used, but in recent years there has been a strong interest in environmental issues, and the release of harmful organic substances from various factories tends to be severely restricted, From the viewpoint of emphasizing employee health, the development of technology to replace spray painting is an urgent task. Under such circumstances, after injecting the paint between the surface of the resin molded product molded in the mold and the cavity surface of the mold, the paint is cured in the mold and the coating film adheres to the surface of the resin molded product An in-mold coating forming method (in-mold coating, hereinafter referred to as “IMC”) for producing a molded article has attracted attention. This IMC is expected not only to improve the quality of the surface of a molded product by bringing a coating film into close contact with the surface, but also to greatly contribute to cost reduction by shortening the coating process.

  The coating material used for the in-mold coating molding of the thermoplastic resin has both the appearance and adhesion of the coating film because the curing property is required to be cured at a lower temperature than the coating material for the thermosetting resin. Development of paints is generally difficult, and the paints that have already been developed for use in the in-mold coating forming method are limited to paints for thermosetting resins and some thermoplastic resins such as ABS resin and nylon. Has been. For this reason, at present, the types of synthetic resins applicable to the in-mold coating molding method are limited to thermosetting resins or some thermoplastic resins such as ABS and nylon. Furthermore, it has been considered that it is technically very difficult to develop a coating material having sufficient adhesion to an olefin resin such as a polypropylene resin or a polyethylene resin because of the structure of the resin.

  In addition, since olefinic resins such as polypropylene resin and polyethylene resin are difficult to adhere even in general spray coating due to the structure of the resin, after applying an intermediate layer such as a primer to the resin surface, paint is applied to the surface of the applied primer. The method of applying is taken. Therefore, it was considered technically extremely difficult to develop a polypropylene resin composition having sufficient coating film adhesion by a one-component coating in-mold coating molding method such as IMC.

  Therefore, in order to carry out the in-mold coating molding method for polyolefin resin, as described in JP-A-2001-170964, a surface material having good adhesion to the paint is stuck on the surface of polyolefin resin. Disclosed is a method of performing molding and injecting paint between the surface of the skin material and the mold cavity surface to obtain a molded product in which a coating film is integrally formed on the surface of the polyolefin resin via the skin material. Yes.

Under such circumstances, as a result of intensive research, the present inventors specified chlorine as a vehicle component comprising an oligomer having a (meth) acrylate group and an ethylenically unsaturated monomer copolymerizable with the oligomer. Acrylic-modified chlorinated polyolefin, organic peroxide, coating material for coating in mold containing polyisocyanate at a specific ratio, and hydroxyl group having a specific hydroxyl value and containing a specific amount of rubber component In-mold coating molding in which the coating paint is integrally formed with good adhesion on the surface of a molded product of a polypropylene resin composition, which is a polyolefin resin, by using a polypropylene resin composition containing The present invention was completed by finding that a body can be obtained.

  The present invention has been made in view of the above-mentioned problems of the prior art, and the coating material for in-mold coating is integrated with the surface of the molded product of the polypropylene resin composition, which is a polyolefin resin, with good adhesion. It is an object of the present invention to provide a mold-in-mold-covered molded body and a method for producing the mold-in-mold-covered molded body.

The in-mold coated molded body according to the present invention is:
The surface of the molded product composed of the hydroxyl group-containing polypropylene-based resin composition (A) is a molded product coated with the coating composition for in-mold coating (B),
Polypropylene resin (i) constituting the hydroxyl group-containing polypropylene resin composition (A), added rubber (ii), and optionally added polymer other than the polypropylene resin (i) and the added rubber (ii) The total hydroxyl value with compound (iii) is 1-40 (KOH mg / g),
Rubber component content in the hydroxyl group-containing polypropylene-based resin composition (A) (added rubber (ii) amount, polypropylene resin (i) component, and optionally 23 ° C. n-decane of the polymer compound (iii) The total amount of the soluble component) is 15 to 80% by mass when the total content of the rubber component and the resin component other than the rubber component is 100% by mass,
The coating composition for in-mold coating (B)
100 parts by mass of vehicle component (a) comprising 10 to 70% by mass of an oligomer having at least two (meth) acrylate groups and 90 to 30% by mass of an ethylenically unsaturated monomer copolymerizable with the oligomer ,
(Meth) acryl-modified chlorinated polyolefin (b) having a chlorine content of 2 to 40% by mass, 5 to 35 parts by mass,
The organic peroxide polymerization initiator (c) is 0.5 to 5 parts by mass, and the polyisocyanate compound (d) is 2 to 20 parts by mass.

  The hydroxyl group-containing polypropylene resin composition (A) is preferably a polypropylene resin composition containing a hydroxyl group-containing polypropylene resin component.

  The added rubber (ii) in the hydroxyl group-containing polypropylene resin composition (A) is preferably an ethylene / α-olefin copolymer.

  The hydroxyl group-containing polypropylene resin composition (A) may contain an inorganic filler.

The first manufacturing method of the in-mold coated molded body according to the present invention is:
A fixed mold having a mold temperature not higher than the melting point of the polypropylene-based resin component in the hydroxyl group-containing polypropylene-based resin composition (A) and having a mold temperature higher than a temperature at which the coating composition for coating an inner mold (B) is cured; In a state where a mold composed of a moving mold is held at a predetermined clamping pressure, a melt of the resin composition (A) is injected into the mold cavity, and the melt is applied for a predetermined time. Is cooled and solidified to the extent that it can withstand the flow pressure of the coating composition (B), and then the mold is slightly opened to form a space between the obtained molded product and the mold cavity surface, The coating composition (B) in the space
And the mold clamping pressure is increased again to hold the mold clamped, and the molded product is taken out after the coating composition (B) is cured.

The second manufacturing method of the in-mold coated molded body according to the present invention is:
A fixed mold having a mold temperature not higher than the melting point of the polypropylene-based resin component in the hydroxyl group-containing polypropylene-based resin composition (A) and having a mold temperature higher than a temperature at which the coating composition for coating an inner mold (B) is cured; In a state where a mold composed of a moving mold is held at a predetermined primary clamping pressure, a melt of the resin composition (A) is injected into the mold cavity, and the clamping force is applied during or after the injection is completed. Was raised to the secondary mold clamping force and held for a predetermined time to cool and solidify the melt so as to withstand the flow pressure of the coating composition (B), and then the mold was slightly opened to obtain A space is formed between the molded product and the mold cavity surface, the coating composition (B) is injected into the space, the mold clamping pressure is increased again, and the mold is clamped and held. The molded body is taken out after the composition (B) is cured.

The third production method of the in-mold coated molded body according to the present invention is:
A fixed mold having a mold temperature not higher than the melting point of the polypropylene-based resin component in the hydroxyl group-containing polypropylene-based resin composition (A) and having a mold temperature higher than a temperature at which the coating composition for coating an inner mold (B) is cured; In a state where a predetermined amount of a mold including a moving mold is opened, a melt of the resin composition (A) is injected into the mold cavity, and the clamping force is increased to a predetermined clamping force during or after the injection is completed. The molten product is cooled and solidified to such an extent that it can withstand the fluid pressure of the coating composition (B) by holding for a predetermined time, and then the mold is slightly opened, and the resulting molded product and mold cavity are obtained. A space is formed between the coating composition (B), the coating composition (B) is injected into the space, the mold clamping pressure is raised again and the mold is clamped, and the coating composition (B) The molded body is taken out after curing.

  According to the present invention, an in-mold coating molded body in which a coating composition for in-mold coating is integrally formed on the surface of a molded product of a polypropylene resin composition with good adhesion, and the in-mold coating The manufacturing method of a molded object can be provided.

  The molded body of the present invention can be used for interior and exterior parts for vehicles such as bumpers, moldings, door trims, instrument panels, trims, and console boxes, interior and exterior parts for home appliances, interior and exterior members for residential building materials, and the like.

  Hereinafter, the in-mold coated molded body and the manufacturing method thereof according to the present invention will be specifically described.

  The in-mold coating molded product according to the present invention comprises a molded product made of a hydroxyl group-containing polypropylene resin composition (A) and a coating of a coating composition for in-mold coating (B) formed on the surface thereof. ing.

  First, the hydroxyl group-containing polypropylene resin composition (A) will be described.

Hydroxyl group-containing polypropylene resin composition (A)
The hydroxyl group-containing polypropylene resin composition (A) used in the present invention comprises a polypropylene resin (i), an added rubber (ii), and other polymer compounds (iii) added as necessary.
, A composition composed of various additives such as an inorganic filler and a color pigment, wherein at least one component of the polypropylene resin (i), the added rubber (ii) and the other polymer compound (iii) is a hydroxyl group have.

That is, the hydroxyl group-containing polypropylene-based resin composition (A) includes a polypropylene resin (i), an added rubber (ii), and a thermoplastic component of other polymer compound (iii) that is added as necessary. It is comprised from inorganic components, such as an inorganic filler (for example, talc) added according to. That is, it contains a resin component, a rubber component, and an inorganic component such as an inorganic filler (for example, talc) added as necessary. The rubber component used herein refers to the added rubber contained in the thermoplastic component, 23 ° C. in the polypropylene resin (i) and the polymer compound (iii).
And the total amount of n-decane soluble in The resin component is the remaining component obtained by removing the rubber component from the thermoplastic component.

  Examples of the polypropylene resin (i) include propylene homopolymer, propylene block copolymer, propylene random copolymer, components modified with a compound containing a hydroxyl group, and the like, and a hydroxyl group-containing propylene homopolymer, a hydroxyl group-containing propylene block copolymer, and a hydroxyl group-containing propylene random copolymer. Is mentioned.

  Examples of the added rubber (ii) include thermoplastic rubbers such as ethylene / α-olefin copolymer and styrene rubber.

Examples of the polymer compound (iii) to be optionally added include thermoplastic polymer compounds such as polyethylene, and thermoplastic polymer compounds modified with a compound containing a hydroxyl group.

The hydroxyl group-containing polypropylene resin composition (A) used in the present invention comprises a polypropylene resin (i) and an added rubber (ii), other polymer compound (iii) added as necessary, an inorganic filler, A composition comprising various additives such as a color pigment, wherein at least one component of the polypropylene resin (i), the added rubber and the other polymer compound (iii) has a hydroxyl group, and the polypropylene resin The rubber component content is 15 to 80 masses when the total amount of thermoplastic components of (i), added rubber (ii), and other polymer compound (iii) added as necessary is 100 mass%. %.

  As the polypropylene resin (i), a polypropylene obtained by polymerization by a known method can be used, and a propylene homopolymer may be used, and a structural unit derived from propylene and an α having 2 to 12 carbon atoms excluding propylene. -It may be a block copolymer or a random copolymer containing structural units derived from olefins.

  As the α-olefin having 2 to 12 carbon atoms excluding propylene, known ones can be used, for example, ethylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, and nonene-1. And chain α-olefins such as decene-1,4-methylpentene-1,4-methylhexene-1,4,4-dimethylpentene, and cyclic α-olefins such as cyclopentene and cyclohexene. These α-olefins can be used alone or in combination of two or more.

  The comonomer content in the propylene random copolymer is 0.5 to 20 mol%, preferably 1 to 15 mol%, more preferably 1 to 10 mol%. The comonomer content in the propylene block copolymer is 0.5 to 50 mol%, preferably 1 to 40 mol%, more preferably 5 to 30 mol%.

Here, the rubber has rubber elasticity at normal temperature, and the rubber component content is 23 ° C. in the added rubber (ii), polypropylene resin (i) and other polymer compound (iii). It is the total with the amount of n-decane solubles.

The polymer compound (iii) refers to a polymer compound added to other than the rubber (ii) added to the polypropylene resin (i).

As the polypropylene resin (i), the added rubber (ii) and the polymer compound (iii), those having a polar group such as an amine group, a ketone group, a carboxyl group, a glycidyl group and a cyano group excluding a hydroxyl group can be used.

As a method for obtaining such a hydroxyl group-containing polypropylene resin composition (A), for example,
(1) To at least one polymer selected from a propylene homopolymer, a propylene block copolymer and a propylene random copolymer, an added rubber and, if necessary, a polymer compound or the like are added, and then modified with a compound containing a hydroxyl group. A method of obtaining a hydroxyl group-containing polypropylene resin composition (A),
(2) At least one modified polymer selected from a propylene homopolymer modified with a compound containing a hydroxyl group, a propylene block copolymer modified with a compound containing a hydroxyl group, and a propylene random copolymer modified with a compound containing a hydroxyl group; A method for obtaining a target hydroxyl group-containing polypropylene resin composition (A) by adding a polymer compound or the like according to
(3) At least one polymer selected from propylene homopolymer, propylene block copolymer and propylene random copolymer, a polypropylene resin component modified with a compound containing a hydroxyl group and / or a polypropylene resin component containing a hydroxyl group, an added rubber, and A method for obtaining a target hydroxyl group-containing polypropylene resin composition (A) by adding a polymer compound or the like as necessary,
(4) A target hydroxyl group-containing polypropylene resin composition (added rubber, a polymer compound containing a hydroxyl group, etc. is added to at least one polymer selected from propylene homopolymer, propylene block copolymer and propylene random copolymer. A) to obtain
(5) At least one polymer selected from propylene homopolymer, propylene block copolymer, and propylene random copolymer, an additive rubber modified with a compound containing a hydroxyl group and / or an additive rubber containing a hydroxyl group, and a polymer compound if necessary And the like to obtain a target hydroxyl group-containing polypropylene resin composition (A). These methods may be used not only alone but also in combination.

Polymer resin (iii) other than the polypropylene resin (i) and the added rubber (ii) optionally added to the polypropylene resin (i) and the added rubber (ii) constituting the hydroxyl group-containing polypropylene resin composition (A) ) And the total amount of hydroxyl groups is 1 to 40 (KOH mg /
g), preferably 2 to 30 (KOH mg / g), more preferably 2 to 20 (KOH mg / g). When the hydroxyl value is lower than 1 (KOH mg / g), the amount of hydroxyl groups in the hydroxyl group-containing polypropylene resin composition (A) is small, so that the surface of the molded article made of this resin composition (A) is coated inside the mold. Since the wettability of the coating composition (B) deteriorates and the amount of urethane bonds produced by the reaction between the isocyanate groups in the coating composition (B) and the hydroxyl groups in the resin composition (A) is reduced, the coating composition (B ) And sufficient adhesion cannot be obtained. On the other hand, if the hydroxyl value is higher than 40, the amount of hydroxyl groups in the resin composition (A) is too large, so that the physical properties such as impact properties of the resin composition are deteriorated, and molding is performed at the time of mold opening or mold release. Surface layer peeling tends to occur on the surface of the object.

  The hydroxyl value is represented by the amount (mg) of potassium hydroxide (Mw = 56) necessary to neutralize 1 g of the sample.

  As a method for obtaining the hydroxyl group-containing polypropylene resin composition (A) used in the present invention, for example, at least one polymer selected from propylene homopolymer, propylene block copolymer and propylene random copolymer as polypropylene resin (i), Add the added rubber (ii) and other various polymer compounds (iii) as necessary, and react these components with the hydroxyl group-containing ethylenically unsaturated compound in the presence of an organic peroxide in an extruder. And a method for obtaining a hydroxyl group-containing polypropylene-based resin composition (A).

  This hydroxyl-containing ethylenically unsaturated compound is a compound having both an ethylenically unsaturated bond and one or more hydroxyl groups in one molecule.

  Specific examples of the hydroxyl group-containing ethylenically unsaturated compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, and 2-hydroxy-3. -Phenoxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, pentaerythritol mono (meth) acrylate, trimethylolpropane (meth) acrylate, tetramethylolethane mono (meta) ) Acrylates, butanediol mono (meth) acrylates, polyethylene glycol mono (meth) acrylates, (meth) acrylic acid esters such as 2- (6-hydroxyhexanoyloxy) ethyl acrylate, etc. And the like. “(Meth) acryl” means “acryl” and / or “methacryl”.

  Further, as the hydroxyl group-containing ethylenically unsaturated compound, 10-undecen-1-ol, 1-octen-3-ol, 2-methanol norbornene, hydroxystyrene, hydroxyethyl vinyl ether, hydroxybutyl vinyl ether, N-methylol acrylamide 2- (meth) acryloyloxyethyl acid phosphate, glycerol monoallyl ether, allyl alcohol, allyloxyethanol, 2-butene-1,4-diol, glycerol monoalcohol and the like can also be used.

  Among these hydroxyl group-containing ethylenically unsaturated compounds, 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate are preferable. A hydroxyl-containing ethylenically unsaturated compound can also be used individually by 1 type, and can also be used in combination of 2 or more type.

As the organic peroxide, specifically,
1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl Peroxyketals such as -4,4-bis- (t-butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane;
Di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, α, α′-bis (t-butylperoxy) hexane, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane , Dialkyl peroxides such as 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3;
Diacyl peroxides such as acetyl peroxide, isobutyl oxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, 2,5-dichlorobenzoyl peroxide, m-trioyl peroxide;
t-butyloxyacetate, t-butylperoxyisobutyrate, t-butylperoxy-2-ethylhexanoate, t-butylperoxylaurate, t-butylperoxybenzoate, di-t-butylperoxyisophthalate, 2, Peroxyesters such as 5-dimethyl-2,5-bis (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxyisopropylcarbonate, cumylperoxyoctate;
Peroxydicarbonates such as di (2-ethylhexyl) peroxydicarbonate, di (3-methyl-3-methoxybutyl) peroxydicarbonate;
Hydroperoxides such as t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, etc. In addition, any organic peroxide that is usually used industrially can be used without particular limitation. Among these organic peroxides, t-butylperoxybenzoate, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexane, t-butylperoxy-2-ethylhexaate, dicumyl peroxide, etc. preferable.

  As a method for obtaining the hydroxyl group-containing polypropylene resin composition (A), there is the addition of a hydroxyl group-containing polypropylene resin component. As a method for introducing a hydroxyl group into the polypropylene resin component to be added, for example, this polypropylene resin component is reacted with a hydroxyl group-containing ethylenically unsaturated compound such as hydroxymethyl methacrylate in the presence of an organic peroxide in an extruder. The method of making it, etc. are mentioned.

  Examples of the polypropylene resin component for introducing a hydroxyl group include a propylene homopolymer, a propylene block copolymer, and a propylene random copolymer, and among them, a propylene homopolymer is preferable.

  As a method for obtaining the hydroxyl group-containing polypropylene resin composition (A), there is addition of a hydroxyl group-containing rubber. Examples of a method for introducing a hydroxyl group into the rubber to be added include a method in which this rubber and a hydroxyl group-containing ethylenically unsaturated compound are reacted in an extruder in the presence of an organic peroxide.

  The hydroxyl group-containing polymer compound added as a method for obtaining the hydroxyl group-containing polypropylene resin composition (A) may be any thermoplastic polymer compound capable of introducing a hydroxyl group.

  Examples of a method for introducing a hydroxyl group into the polymer compound to be added include a method in which this polymer compound and a hydroxyl group-containing ethylenically unsaturated compound are reacted in an extruder in the presence of an organic peroxide.

  Since the hydroxyl group-containing polypropylene resin composition (A) is polypropylene, the hydroxyl group-containing composition to be added is modified with a hydroxyl group-containing compound such as hydroxymethyl methacrylate from a hydroxyl group-containing rubber or a hydroxyl group-containing polymer compound. The hydroxyl group-containing polypropylene resin component is preferred because of better compatibility.

  Further, a compatibilizing agent that increases the compatibility of the hydroxyl group-containing rubber, the hydroxyl group-containing polypropylene resin component, and the hydroxyl group-containing polymer compound in the hydroxyl group-containing polypropylene resin composition (A) may be added. Good.

The rubber component content in the hydroxyl group-containing polypropylene resin composition (A) is the amount of the added rubber (i) and n-decane at 23 ° C. of the polypropylene resin (i) and the other polymer compound (iii). When the total content of the thermoplastic component of the polypropylene resin (i), the added rubber (ii), and the polymer compound (iii) added as necessary is 100% by mass. It is 15-80 mass%, Preferably it is 15-70 mass%, More preferably, it is 20-60 mass%. That is, the total content of the resin components in the resin composition (A) is 20 to 85% by mass, preferably 30 to 85% by mass, and more preferably 40 to 80% by mass.

  When the hydroxyl group-containing polypropylene resin composition (A) having a rubber component content in the above range is used, an integrally molded product having good adhesion to the coating composition (B) can be obtained.

  For example, when the hydroxyl group-containing polypropylene resin composition (A) is composed of a propylene homopolymer, an added rubber and a hydroxyl group-containing polypropylene resin component modified with a propylene homopolymer and an inorganic filler, The amount corresponds to the amount of rubber added, and the rubber component content is the amount of thermoplastic component excluding the inorganic filler (total amount of propylene homopolymer, added rubber and hydroxyl group-containing polypropylene resin component). It is expressed as a content in the case of mass%.

  When the hydroxyl group-containing polypropylene resin composition (A) is composed of a propylene block copolymer, an added rubber, and a hydroxyl group-containing polypropylene resin component modified with a propylene homopolymer and an inorganic filler, The amount is the total amount of the added rubber and the ethylene / propylene copolymer in the propylene block copolymer, and the rubber component content is the amount of the thermoplastic component excluding the inorganic filler (propylene block copolymer, added). It is expressed as a total amount when the total amount of rubber and hydroxyl group-containing polypropylene resin component is 100% by mass.

  The amount of the ethylene / propylene copolymer in the propylene block copolymer is represented by the amount of n-decane soluble component (% by mass) at room temperature.

  The amount of decane soluble at room temperature (23 ° C.) is measured as follows. That is, 3 g of a polymer sample, 20 mg of 2,6-di-tert-butyl-4-methylphenol, and 500 ml of n-decane are placed in a 1 liter flask equipped with a stirrer and dissolved by heating in an oil bath at 145 ° C. After the polymer sample has dissolved, it is cooled to room temperature over about 8 hours and then held on a 23 ° C. water bath for 8 hours. The precipitated polymer and the n-decane solution containing the dissolved polymer are separated by filtration with a G-4 (or G-2) glass filter. The solution thus obtained was heated under the conditions of 10 mmHg and 150 ° C., and the polymer dissolved in the n-decane solution was dried until a fixed amount was obtained. The 23 ° C. decane soluble content of the polymer is calculated as a percentage of the mass of the polymer sample.

  Examples of the rubber to be added include ethylene / α-olefin copolymers such as ethylene / butene copolymers, ethylene / octene copolymers and ethylene / propylene copolymers, and SEBS (styrene-ethylene / butylene). -Styrene block copolymer). In the present invention, rubbers other than these rubbers can also be used as the rubber to be added.

  When the rubber as described above is added, the chlorinated polyolefin component contained in the coating composition for in-mold coating (B) becomes a rubber oriented on the surface of the molded product of the hydroxyl group-containing polypropylene resin composition (A). Since it is considered that it partially penetrates and swells and binds, the adhesion between the coating composition (B) and the resin composition (A) becomes strong.

  The Mooney viscosity ML (1 + 4) (100 ° C.) of the rubber to be added is preferably in the range of 5 to 60, more preferably 10 to 45. If the Mooney viscosity of the rubber is lower than 5, surface layer peeling tends to occur on the surface of the molded product when the mold is opened or when the molded product is released. If the Mooney viscosity of the rubber is higher than 60, the rubber on the surface layer of the molded product will not be flattened even if the resin composition (A) is injection-molded. Therefore, the molded product and the coating composition for in-mold coating (B ) Deteriorates.

  In order to improve the rigidity of the molded product composed of the hydroxyl group-containing polypropylene resin composition (A), an inorganic filler can be added as needed without impairing the object of the present invention.

  Specific examples of the inorganic filler include talc and calcium carbonate. An inorganic filler is normally used in the ratio of 0.1-60 mass% with respect to 100 mass% of resin compositions (A).

  Further, depending on the purpose, the hydroxyl group-containing polypropylene-based resin composition (A) may have various additives such as a heat resistance stabilizer, a weather resistance stabilizer, and other additives and color pigments that do not inhibit the curing of the coating composition for in-mold coating (B). Can be added.

As the hydroxyl group-containing polypropylene resin composition (A) used in the present invention,
At least one polypropylene selected from propylene homopolymer, propylene block copolymer and propylene random copolymer as polypropylene resin (i), preferably 25 to 90% by mass,
The additive rubber (ii) is 5 to 80% by mass, preferably 10 to 75% by mass (the total of the polypropylene resin (i) and the additive rubber (ii) is 100% by mass), and at least one of the polypropylene and rubber A resin composition having a hydroxyl group and a hydroxyl value in the range of 1 to 40 (KOH mg / g), or at least selected from propylene homopolymer, propylene block copolymer and propylene random copolymer as polypropylene resin (i) 20-95% by mass of one kind of polypropylene, preferably 25-90% by mass,
Added rubber (ii) 5 to 80% by mass, preferably 10 to 75% by mass (the total of polypropylene resin (i) and added rubber (ii) is 100% by mass);
1 to 60% by mass of the polymer compound (iii) other than the polypropylene resin (i) and the added rubber (ii) with respect to a total of 100% by mass of the polypropylene resin (i) and the added rubber (ii).
The polypropylene resin (i), the added rubber (ii) and the polymer compound (iii)
A resin composition having at least one hydroxyl group and having a hydroxyl value in the range of 1 to 40 (KOH mg / g) is preferably used.

  Moreover, 1-60 mass% of inorganic fillers with respect to the total 100 mass% of polypropylene resin (i) and addition rubber | gum (ii) as needed to these resin compositions, Preferably 1-50 mass. %, And pigments can be added in amounts of 1-10% by weight.

  Examples of the additive rubber (ii) include ethylene / α-olefin copolymers such as ethylene / butene copolymers, ethylene / octene copolymers and ethylene / propylene copolymers, and SEBS (styrene-ethylene / butylene). -Styrene block copolymer). Among these, an ethylene / α-olefin copolymer is preferable because of its low cost. This added rubber (ii) does not necessarily mean exactly the same rubber component as described above. For example, an n-decane soluble component at 23 ° C. in a polypropylene resin component such as a propylene block copolymer and an n-decane soluble component at 23 ° C. in a polymer compound are included in the “rubber” herein. Absent.

Examples of the polymer compound (iii) other than the above polypropylene resin (i) and additive rubber (ii) include α-olefin polymers other than polypropylene such as polyethylene and polybutene, and α-olefin having 4 to 20 carbon atoms with ethylene. Examples thereof include linear low density polyethylene copolymerized with olefin, preferably α-olefin having 4 to 12 carbon atoms. The content of α-olefin in the linear low density polyethylene is about 1 to 10 mol%, preferably about 1.5 to 8 mol. As the linear polyethylene copolymerized with α-olefin, one having a density of about 0.900 to 0.920 g / cm ³ is preferable because it has an excellent effect of improving impact strength.

  Examples of the pigment include carbon black, iron black, and titanium white. A coloring pigment that does not inhibit the curing of the in-mold coating composition (B) can be added depending on the purpose.

  Among the preferably used hydroxyl group-containing polypropylene resin composition (A), for example, propylene block copolymer 45 to 65% by mass, hydroxyl group-containing propylene homopolymer (hydroxyl-modified product of propylene homopolymer) 20 to 40% by mass, and added rubber A resin composition comprising 15 to 35% by mass and 10 to 30% by mass of talc (provided that the total of the propylene block copolymer, the hydroxyl group-containing propylene homopolymer and the added rubber is 100% by mass) is particularly preferably used. . This resin composition can be produced by the method (3) mentioned as the method for obtaining the hydroxyl group-containing polypropylene resin composition (A).

  Next, the coating composition for in-mold coating (B) used in the present invention will be described.

Coating composition for in-mold coating (B)
The coating composition for in-mold coating (B) used in the present invention comprises a vehicle component (including an oligomer having at least two (meth) acrylate groups) and an ethylenically unsaturated monomer copolymerizable with the oligomer ( a), (meth) acryl-modified chlorinated polyolefin (b), organic peroxide polymerization initiator (c) and polyisocyanate compound (d).

[Vehicle component (a)]
As the oligomer having at least two (meth) acrylate groups of the vehicle component (a) used in the present invention, specifically, urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, poly Examples include ether (meth) acrylates and silicon (meth) acrylate oligomers. The weight average molecular weight (Mw) of these oligomers may vary depending on the type, but generally 5
It is appropriate to set it to 00 to 5,000, preferably 1,000 to 3,000.

  The oligomer having the (meth) acrylate group suitably has at least 2, preferably 2 to 4, (meth) acrylate groups in one molecule.

The urethane (meth) acrylate oligomer is, for example, (i) an organic diisocyanate compound, (ii) an organic polyol compound, and (iii) a hydroxyalkyl (meth) acrylate having an NCO / OH ratio of, for example, 0.8 to 1 0.0, preferably 0.9 to 1.0, and mixed by an abundance ratio, and can be produced by an ordinary method. An oligomer having a large number of hydroxyl groups can be obtained by using excessive hydroxyl groups or using a large amount of hydroxyalkyl (meth) acrylate.

Specifically, first, (i) an organic diisocyanate compound and (ii) an organic polyol compound are reacted in the presence of a urethanization catalyst such as dibutyltin dilaurate to obtain an isocyanate-terminated polyurethane prepolymer. Subsequently, the urethane (meth) acrylate oligomer can be produced by reacting with (iii) hydroxyalkyl (meth) acrylate until most of the free isocyanate groups are reacted. The ratio of (ii) the organic polyol compound and (iii) hydroxyalkyl (meth) acrylate is suitably about 0.2 to 0.5 mol of component (ii), for example, with respect to 1 mol of component (iii). It is.

  Specific examples of the organic diisocyanate compound (i) include 1,2-diisocyanatoethane, 1,2-diisocyanatopropane, 1,3-diisocyanatopropane, hexamethylene diisocyanate, lysine diisocyanate, and trimethyl. Hexamethylene diisocyanate, tetramethylene diisocyanate, bis (4-isocyanatocyclohexyl) methane, methylcyclohexane-2,4-diisocyanate, methylcyclohexane-2,6-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, 1, Examples include 3-bis (isocyanatoethyl) cyclohexane, 1,3-bis (isocyanatomethyl) benzene, 1,3-bis (isocyanato-1-methylethyl) benzene, and the like. These (i) organic diisocyanate compounds can be used alone or in combination of two or more.

  As said (ii) organic polyol compound, an organic diol compound is preferable. Specific examples of the organic diol compound include alkyl diols, polyether diols, and polyester diols.

  Examples of the alkyl diol include ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1, Typical examples include 7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,4-cyclohexanediol, and the like.

  The polyether diol can be synthesized, for example, by polymerization of aldehyde, alkylene oxide, glycol or the like by a known method. For example, a polyether diol can be obtained by addition polymerization of formaldehyde, ethylene oxide, propylene oxide, tetramethylene oxide or the like to an alkyl diol under appropriate conditions.

  As the polyester diol, for example, an esterification reaction product obtained by reacting a saturated dicarboxylic acid and / or an acid anhydride thereof with an excess of alkyl diol can be used. An ester obtained by polymerizing at least one compound selected from the group consisting of hydroxycarboxylic acid, a lactone that is an intramolecular ester of hydroxycarboxylic acid, and lactide that is an intermolecular ester of hydroxycarboxylic acid, with an alkyldiol. The reaction product can also be used.

  The above-mentioned (ii) organic polyol compounds can be used alone or in combination of two or more.

  Specific examples of the (iii) hydroxyalkyl (meth) acrylate include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 4-hydroxybutyl (meth) acrylate. .

  The polyester (meth) acrylate as an oligomer used in the present invention can be produced, for example, by a reaction between a polyester polyol having a hydroxyl group at the terminal and an unsaturated carboxylic acid.

Such a polyester polyol can be typically produced by esterifying a saturated or unsaturated dicarboxylic acid or an acid anhydride thereof with an excess amount of an alkylene diol.

  Typical examples of the dicarboxylic acid include oxalic acid, succinic acid, adipic acid, fumaric acid, maleic acid and the like.

  Moreover, as said alkylene diol, ethylene glycol, propylene glycol, butanediol, pentanediol etc. can be mentioned as a typical thing, for example.

  The epoxy (meth) acrylate oligomer as an oligomer used in the present invention is such that, for example, an epoxy compound and an unsaturated carboxylic acid have a carboxyl group equivalent of, for example, 0.5 to 1.5 per epoxy group equivalent. It is used at a small ratio and is produced by a ring-opening addition reaction of an acid to a normal epoxy group.

  Examples of the epoxy compound include bisphenol A type epoxy and phenolic novolac type epoxy.

  Examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, and the like.

  The polyether (meth) acrylate as an oligomer used in the present invention can be produced, for example, by reacting a polyether polyol such as polyethylene glycol or polypropylene glycol with the unsaturated carboxylic acid.

  The silicon (meth) acrylate oligomer as an oligomer used in the present invention is an oligomer produced by, for example, an ester reaction between a hydroxyl group of an alcoholic siloxane compound and (meth) acrylic acid. Silicon (meth) acrylate oligomers are particularly excellent in releasability and smoothness.

  Specific examples of the ethylenically unsaturated monomer copolymerizable with the oligomer having the (meth) acrylate group include styrene, vinyltoluene, methyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth). Acrylate, tetrahydrofurfuryl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, N-vinyl-2-pyrrolidone, ethylene glycol di (meth) acrylate, tripropylene glycol di (meth) ) Acrylate, 1,6-hexanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, and the like.

  These ethylenically unsaturated monomers can be used alone or in combination of two or more.

  The oligomer having at least two (meth) acrylate groups and the ethylenically unsaturated monomer copolymerizable with the oligomer are 10/90 to 70/30, preferably 20/80 to mass ratio [oligomer / monomer]. It is suitable to use at a ratio of 60/40. When this mass ratio is lower than 10/90, the viscosity of the coating composition for coating in the mold (B) becomes too low, or bubbles are taken into the coating composition for coating when flowing in the mold (B). This is not preferable. On the other hand, if the mass ratio is higher than 70/30, the viscosity of the coating composition (B) for coating in the mold is remarkably increased and the fluidity in the mold is inferior, which is not preferable.

[(Meth) acryl-modified chlorinated polyolefin (b)]
The (meth) acryl-modified chlorinated polyolefin (b) used in the present invention is obtained, for example, by graft polymerization of a (meth) acryl monomer to a chlorinated polyolefin in the presence of a peroxide.

  Specific examples of the (meth) acrylic monomer include (meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. Etc.

  The (meth) acryl-modified chlorinated polyolefin (b) is a hydroxyl group-containing (meth) acryl-modified chlorine obtained by graft-polymerizing a hydroxyl group-containing (meth) acryl monomer to a chlorinated polyolefin in the presence of a peroxide. It may be a modified polyolefin.

  Examples of the hydroxyl group-containing (meth) acrylic monomer used here include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and the like.

  Such (meth) acryl-modified chlorinated polyolefin (b) can be used singly or in combination of two or more.

  The chlorine content of the (meth) acryl-modified chlorinated polyolefin (b) used in the present invention is 2 to 40% by mass, preferably 2 to 30% by mass, and more preferably 3 to 20% by mass. If this chlorine content is 2% by mass or more, a coating composition for in-mold coating (B) having good storage stability can be obtained without lowering the compatibility with the vehicle component (a). A smooth coating film is obtained. On the other hand, if the chlorine content is 40% by mass or less, good adhesion to a molded product made of the resin composition (A) can be obtained.

  The (meth) acryl-modified chlorinated polyolefin (b) is 5 to 35 parts by weight, preferably 7 to 30 parts by weight, more preferably 7 to 20 parts by weight with respect to 100 parts by weight of the vehicle component (a). It is appropriate to use. If the blending amount of the (meth) acryl-modified chlorinated polyolefin (b) is 5 parts by mass or more, good adhesion to the molded product can be obtained, while if the amount is 35 parts by mass or less, a mold is obtained. Since the viscosity of the coating composition for inner coating (B) does not increase remarkably and the fluidity in the mold does not decrease, a uniform coating film can be obtained.

[Organic peroxide polymerization initiator (c)]
The organic peroxide polymerization initiator (c) used in the present invention generates free radicals, and the coating composition (B) for coating covers the surface of the molded product in the mold. The organic peroxide polymerization initiator (c) is thermally decomposed by the heat of the molding resin to generate active radicals, and the coating composition (B) for coating is cured by radical polymerization.

  As the organic peroxide, one having a high decomposition rate is desirable from the viewpoint of the molding cycle, but on the contrary, such a one has poor stability.

  The organic peroxide polymerization initiator (c) is preferably an organic peroxide having a 1 minute half-life temperature of 150 ° C. or lower. Representative examples of such organic peroxides include, for example, lauroyl peroxide, benzoyl peroxide, t-amylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, Bis (4-t-butylcyclohexyl) peroxycarbonate, t-hexylperoxy-2-ethylhexanoate, and the like are preferable. Here, the 1-minute half-life temperature refers to a temperature at which the concentration of the organic peroxide is reduced to the initial half in 1 minute.

  The compounding amount of the organic peroxide polymerization initiator (c) is 0.5 to 5 parts by mass, preferably 0.7 to 4 parts by mass, more preferably 1 to 100 parts by mass of the vehicle component (a). 3 parts by weight is appropriate. If the compounding amount of the organic peroxide polymerization initiator (c) is 0.5 parts by mass or more, the curing reaction proceeds sufficiently without taking a long time. On the other hand, if the blending amount of the organic peroxide polymerization initiator (c) is 5 parts by mass or less, a rapid reaction is not started in the mold, and the molded product made of the resin composition (A) Good adhesion can be achieved.

[Polyisocyanate compound (d)]
The polyisocyanate compound (d) used in the present invention is not particularly limited as long as it is a polyisocyanate compound that has been conventionally used for coatings, for example, aromatic polyisocyanate, aliphatic polyisocyanate, alicyclic Various polyisocyanates such as polyisocyanate can be used.

Examples of such polyisocyanates include aromatic diisocyanates such as toluene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), and xylene diisocyanate (XDI); hexamethylene diisocyanate (HMDI), lysine diisocyanate ( LDI), aliphatic polyisocyanates such as 2-isocyanatoethyl-2,6-diisocyanate caproate (LTI); alicyclic polyisocyanates such as isophorone diisocyanate (IPDI) and hydrogenated xylene diisocyanate (H6XDI) Can be mentioned. These polyisocyanate compounds (d) can be used alone or in combination of two or more.

  Moreover, you may use polyisocyanate with forms, such as a burette type as a prepolymer, an adductor type, an isocyanurate type. From the viewpoint of weather resistance, it is preferable to use an aliphatic polyisocyanate.

  The compounding amount of the polyisocyanate compound (d) is 2 to 20 parts by mass, preferably 2 to 15 parts by mass, more preferably 2.5 to 10 parts by mass with respect to 100 parts by mass of the vehicle component (a). Is appropriate. If the compounding quantity of a polyisocyanate compound (d) is 2 mass parts or more, favorable adhesiveness with the molded object which consists of a resin composition (A) will be obtained. On the other hand, if the blending amount is 20 parts by mass or less, a molded body having a good appearance without glossiness or the like can be obtained.

[Other ingredients]
If necessary, a release agent can be further added to the coating composition (B) used in the present invention as long as the object of the present invention is not impaired.

  Specific examples of the release agent include stearic acid, zinc stearate, soybean oil lecithin, silicone oil, fatty acid ester, fatty acid alcohol dibasic acid ester, and the like.

  The compounding amount of the release agent is suitably, for example, 0.1 to 3 parts by mass with respect to 100 parts by mass of the vehicle component (a). A mold release effect is exhibited within this range.

  Further, the coating composition (B) used in the present invention may further include various color pigments, extender pigments and the like that have been conventionally used for plastics and paints, as necessary. It can mix | blend in the range which does not impair.

Specific examples of the color pigment include titanium dioxide, titanium yellow, hansa yellow, molybdate orange, benzidine orange, quinacridone red, phthalocyanine green, cobalt blue, ultramarine blue, carbon black, and iron oxide. Further, the pigment may be a scaly pigment such as mica treated with powdered or flaky iron oxide, nickel, aluminum, graphite, titanium oxide or the like.

  Specific examples of extender pigments include calcium carbonate, talc, barium sulfate, aluminum hydroxide, and clay.

  If necessary, the coating composition (B) used in the present invention may be added with various additives such as an antioxidant, an ultraviolet absorber, a curing accelerator, a pigment dispersant, and an antifoaming agent. It can mix | blend in the range which is not impaired.

  Next, the manufacturing method of the in-mold coating molded product according to the present invention will be described with reference to FIG.

  FIG. 1 is an explanatory view showing the overall configuration of an in-mold coating forming apparatus (hereinafter referred to as “IMC apparatus”) used in the method for manufacturing an in-mold covering molded body according to the present invention.

  The IMC device 100 uses a toggle type injection molding machine, and is roughly composed of a mold clamping device 10, an injection device 20, a control device 30, and a mold device 50.

  The mold clamping device 10 includes a fixed platen 11 and a movable platen 12 to which the mold device 50 is attached. The mold clamping device 10 is guided by a tie rod 14 and driven by a mold clamping driving hydraulic cylinder (hereinafter referred to as “clamping cylinder”) 13. The mold plate 50 is configured to open and close when the movable plate 12 moved forward and backward is moved forward and backward with respect to the fixed plate 11.

  In order to carry out this in-mold coating, an injection molding machine having a toggle type clamping mechanism is effective as described in JP-A-2001-38783. The reason is that when the movable mold 52 and the fixed mold 51 are opened largely, a large stroke amount can be obtained while the mold clamping cylinder 13 is driven at a relatively low hydraulic pressure. Conversely, immediately before the mold is closed. Because of the toggle boost characteristic that the mold moves slightly even with a large stroke of the clamping cylinder, the mold can be operated quickly and the mold can be opened with a high degree of accuracy. This is because both are compatible. Further, in the toggle type mold clamping mechanism, the actuator for opening and closing the mold and the actuator for generating the mold clamping force are the same mold clamping cylinder 13, so that the transition from the mold open state to the predetermined mold clamping state can be performed quickly. This quick operation is effective for re-clamping after injecting the paint.

  In the injection device 20, a screw 21 having a spiral flight is rotatably driven by a hydraulic motor 23 along the inner peripheral surface of a cylindrical barrel 22 and can be freely moved forward and backward. Yes. As the screw 21 rotates, the resin pellets supplied into the hopper 25 are sent to the front of the screw 21 and are heated by a heater (not shown) attached to the outer peripheral surface of the barrel 22 during this time. The resin pellets are melted by receiving a kneading operation by the rotation of the screw 21.

  When the amount of the molten resin sent to the front of the screw 21 reaches a preset amount, the rotary motion of the hydraulic motor 23 is stopped and the injection cylinder 24 is driven to advance the screw 21. The molten resin stored in front of the screw 21 is injected into the mold cavity 53 of the mold apparatus 50 via the nozzle 26.

  The mold apparatus 50 includes a fixed mold 51 attached to the fixed platen 11 and a movable mold 52 attached to the movable platen 12, and a coating agent is injected into the mold cavity 53 in the movable mold 52. A coating material injection machine 55 is disposed.

  Next, the configuration of the control device 30 will be described. As shown in FIG. 1, the control device 30 links the operation of the mold clamping device 10 and the operation of the injection device 20 to control the overall system of the control device 30, and the injection device. And an injection control unit 38 for controlling the operation of 20. These control units 31 and 38 have the same control performance as the control unit in a normal injection molding machine.

  On the other hand, as a control unit having a control function unique to the IMC device 100 of the present invention, the coating material injection machine 55 receives a molding condition data signal (referring to a change pattern of molding conditions; the same applies hereinafter) from the mold clamping condition setting unit 32. In response to the molding condition data signal transmitted from the injection machine control unit 35 for controlling the operation of the mold, the mold clamping condition setting unit 32 and the change pattern storage unit 34 described later, the mold clamping is performed while feeding back the measurement signal of the stroke sensor 16. The mold clamping control unit 33 for controlling the servo valve 15, the mold opening amounts of the molds 51 and 52 (hereinafter referred to as “mold opening amount”) sent from the mold clamping condition setting unit 32, and the molds of the molds 51 and 52 A change pattern storage unit 34 that is converted into a molding condition data signal of a clamping force (hereinafter referred to as “clamping force”) and sent to the mold clamping control unit 33 is provided.

  Here, in the mold clamping condition setting unit 32, each molding of the opening / closing speed of the mold clamping device 10, the operation timing, the mold opening amount, the mold clamping force, the injection amount of the coating material injector 55, the injection speed, the injection timing, and the injection pressure is performed. A condition is set. Then, the mold clamping condition setting unit 32 transmits the molding condition data signal to the injection machine control unit 35 regarding the molding conditions regarding the injection amount, the injection speed, the injection timing, and the injection pressure of the coating material injector 55, and the mold clamping device The molding condition data signal is sent to the mold clamping control unit 33 for molding conditions related to the opening / closing speed and the operation timing of 10, and the molding condition data signal is sent to the change pattern storage unit 34 for molding conditions related to the mold opening amount and the clamping force. Send to.

  Prior to control, the change pattern storage unit 34 stores a correlation between the stroke of the clamping cylinder 13 and the mold opening amount, and a correlation between the stroke of the clamping cylinder 13 and the clamping force. . The change pattern storage unit 34 converts the molding condition data signal transmitted from the mold clamping condition setting unit 32 into a stroke of the mold clamping cylinder 13 based on the stored correlation, and the mold clamping control unit 33. Send to.

  By the way, prior to control, the change pattern storage unit 34 stores the correlation between the stroke of the clamping cylinder 13 and the mold opening amount and the correlation between the stroke of the clamping cylinder 13 and the clamping force. is required.

  For this reason, after the mold apparatus 50 is attached to the fixed platen 11 and the movable platen 12, the die height adjustment and the mold clamping according to the mold thickness (die height) of the mold apparatus 50 are performed by the same procedure as that of normal injection molding. In the state where the force adjustment is completed, the change pattern storage unit 34 continuously receives the detection signals of the stroke sensor 16, the mold opening amount sensor 17, and the mold clamping force sensor 18 while opening and closing the mold apparatus 50. Thus, the correlation between the stroke of the mold clamping cylinder 13 and the mold opening amount and the correlation between the stroke of the mold clamping cylinder 13 and the mold clamping force are calculated and stored.

  Next, the operation content of the IMC device 100 when performing in-mold coating using the IMC device 100 having the control device 30 configured as described above will be described.

  First, the 1st manufacturing method of the metal mold | die coating molded object which concerns on this invention is demonstrated using FIG.

The first manufacturing method of the in-mold coated molded body The mold closing set in the mold clamping condition setting unit 32 while performing feedback control by the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping. According to the speed pattern, the movable mold 52 is moved forward from the mold opening limit position by the mold clamping cylinder 13 and brought into contact with the fixed mold 51. Subsequently, while performing feedback control using the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping, the molding condition data signal (the mold clamping force of the mold clamping force) set in the mold clamping condition setting unit 32. In accordance with the change pattern), the movable mold 52 is further advanced by the mold clamping cylinder 13 to extend the tie rod 14 and apply a predetermined mold clamping force to the mold apparatus 50. At this time, the movable mold 52 and the fixed mold 51 are not more than the melting point of the polypropylene resin (i) in the hydroxyl group-containing polypropylene resin composition (A), and the coating composition (B) ) Is injected, the coating composition (B) is kept at a suitable temperature so as to cure in the mold. It should be noted that the mold apparatus applicable to the present invention needs to have a structure in which the paint does not leak from the split surface even when the mold is slightly opened during the coating agent injection described later. The mold apparatus 50 described here has a structure in which the coating surface does not leak from the split surface even if the mold is slightly opened by making the split surface a shear edge structure.

  When the screw 21 is advanced by the injection cylinder 24 while controlling the opening degree of the injection servo valve 27 by a control signal transmitted from the injection control unit at a predetermined operation timing during the operation of the mold clamping device 10, The molten resin (the resin composition (A)) stored in front of the screw 21 is injected into the mold cavity 53 through the nozzle 26 to form a resin molded product. The operation timing signals are exchanged by the molding device control unit 31 so that the operation of the mold clamping device 10 and the operation of the injection device 20 are linked.

  The molten resin injected into the mold is subjected to a holding pressure for a certain period of time as in general injection molding, and an amount of resin solidified and contracted during that time is additionally introduced. Then, the molten resin is solidified in a state where the clamping force is maintained even after the pressure holding is completed.

  When the resin in the mold has solidified to some extent and the surface can withstand the injection pressure of the coating composition (B), the movable mold 52 is then moved backward by the mold clamping cylinder 13 and the mold clamping control unit 33 A mold opening amount set in the mold clamping condition setting unit 32 is given by the control signal to be transmitted and the servo valve 15 for mold clamping while performing feedback control, and between the surface of the resin molding and the mold cavity 53 surface. After providing the gap, the coating material is injected by the control signal transmitted from the injector control unit 35 in accordance with the injection amount, injection speed, injection timing, and injection pressure of the coating material injector 55 set in the mold clamping condition setting unit 32. The machine 55 is driven to inject the coating composition (B) as a coating agent into the mold cavity 53.

  Subsequently, while the feedback control is performed by the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping, the movable mold 52 is advanced again by the mold clamping cylinder 13 and is set in the mold clamping condition setting unit 32. The mold clamping force is generated according to the molding condition data of the mold clamping force. In this way, it is possible to spread the injected coating composition (B) over the entire surface of the resin molded product and to provide optimum pressure conditions for the appearance and adhesion strength of the coating film.

  Since the mold temperature is maintained at a temperature at which the coating composition (B) is cured, the coating composition (B) is cured while being held with the set clamping force. At this time, since the coating composition (B) is cured while being pressed against the mold surface, the surface condition of the mold is accurately transferred to the coating film surface of the coating composition (B). Become.

Thereafter, the mold clamping cylinder 13 is controlled according to the operation timing and mold opening speed pattern set in the mold clamping condition setting unit 32 while performing feedback control by the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping. Thus, the movable mold 52 is retracted to a predetermined mold opening position, and the molded body covered with the coating composition (B) is taken out from the mold apparatus 50. Thus, one cycle is completed.

  In addition, the temperature at which the coating composition for in-mold coating (B) is cured is preferably not higher than the melting point of the polypropylene resin (i) in the hydroxyl group-containing polypropylene resin composition (A), and the resin composition ( The melting point of the polypropylene resin (i) in A) is preferably 20 ° C. or less, and more preferably 30 ° C. or less than the melting point of the polypropylene resin (i) in the resin composition (A). When two or more types of polypropylene resin components are contained in the resin composition (A), the melting point of the polypropylene resin (i) is based on the melting point of the polypropylene resin component having the highest melting point. .

  Here, as a method for measuring the melting point of the polypropylene resin component, for example, after annealing the polypropylene resin component pellets at 230 ° C. for 10 minutes, the temperature is increased to 30 ° C. using a differential scanning calorimeter (DSC). There is a method in which the temperature is lowered at a rate of ° C./min and then held for 1 minute, the temperature is raised at a rate of 10 ° C./min, the temperature having the maximum amount of absorbed heat is obtained, and this temperature is taken as the melting point (Tm).

  The mold temperature at the time of molding can cool the hydroxyl group-containing polypropylene resin composition (A) to such an extent that it can withstand the flow of the coating composition (B) for coating in the mold. It is preferable to set the coating composition (B) in a range where it can be cured, and it is not higher than the melting point of the polypropylene resin (i) of the hydroxyl group-containing polypropylene resin composition (A), preferably not higher than 5 ° C. from the melting point. More preferably, the melting point is 10 ° C. or lower than the melting point, and is higher than the curing temperature of the coating composition for in-mold coating (B), preferably 5 ° C. or higher, more preferably 10 ° C. or higher than the curing temperature. .

  The mold temperature referred to in the present invention means the set temperature of the mold, but if there is a large gap between the set temperature of the mold and the mold temperature near the mold cavity, Of course, it is preferable to take this into consideration, and the mold temperature in the vicinity of the mold cavity immediately before injecting the hydroxyl group-containing polypropylene resin composition (A) into the mold is set to the above temperature range. Needless to say, this is within the scope of the invention.

  Next, the 2nd manufacturing method of the metal mold | die coating molded object which concerns on this invention is demonstrated using FIG.

The second manufacturing method (injection compression molding method)
In-mold coating method used)
The mold clamping cylinder 13 moves the movable mold according to the mold closing speed pattern set in the mold clamping condition setting unit 32 while performing feedback control with the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping. The mold 52 is moved forward from the mold opening limit position and brought into contact with the fixed mold 51. Subsequently, while performing feedback control using the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping, the molding condition data signal (the mold clamping force of the mold clamping force) set in the mold clamping condition setting unit 32. In accordance with the change pattern), the movable mold 52 is further advanced by the mold clamping cylinder 13 to extend the tie rod 14 and to apply the first mold clamping force to the mold apparatus 50. The first mold clamping force (sometimes referred to as primary mold clamping pressure) is injection-filled by the injection filling pressure of the resin composition (A) in consideration of the injection filling process of the resin composition (A) described later. The mold clamping force is set so that the split surface of the mold device 50 is slightly opened during the process. At this time, the movable mold 52 and the fixed mold 51 are injected with the coating composition (B) as a coating agent at a melting point or lower of the polypropylene resin (i) in the hydroxyl group-containing polypropylene resin composition (A). After that, the coating composition (B) is kept at an appropriate temperature so as to be cured in the mold. The mold device 50 described here has a structure in which the split surface has a shear edge structure, so that the paint does not leak from the split surface even when the mold is slightly opened at the time of resin filling and coating agent injection. did.

  When the screw 21 is advanced by the injection cylinder 24 while controlling the opening degree of the injection servo valve 27 by a control signal transmitted from the injection control unit at a predetermined operation timing during the operation of the mold clamping device 10, The molten resin (the resin composition (A)) stored in front of the screw 21 is injected into the mold cavity 53 through the nozzle 26 to form a resin molded product. The operation timing signals are exchanged by the molding device control unit 31 so that the operation of the mold clamping device 10 and the operation of the injection device 20 are linked.

  In the second manufacturing method using the injection compression molding method, the control signal and the mold transmitted from the mold clamping control unit 33 while the molten resin is injected into the mold or after the injection of the molten resin is completed. While performing feedback control using the servo valve 15 for clamping, the movable mold 52 is moved by the mold clamping cylinder 13 in accordance with a molding condition data signal (clamping force change pattern) of the mold clamping force set in the mold clamping condition setting unit 32. Further, the tie rod 14 is further extended to increase the clamping force to the second clamping force.

  The advantage of using the injection compression method is that the first mold clamping force is not sufficient to resist the injection pressure, so that when the molten resin is injected, the mold will open slightly and the resin flow pressure will decrease, Since the gas in the mold easily escapes from the cavity 53, the residual stress remaining in the molded product is less than that of normal injection molding. Then, by applying the second clamping force during injection or after completion of injection, the surface state of the molded product such as sink marks can be equivalent to that of a normal injection molded product. Thereafter, the molten resin is solidified while maintaining the second clamping force.

  When the resin in the mold has solidified to some extent and the surface can withstand the injection pressure of the coating composition (B), the movable mold 52 is then moved backward by the mold clamping cylinder 13 and the mold clamping control unit 33 A mold opening amount set in the mold clamping condition setting unit 32 is given by the control signal to be transmitted and the servo valve 15 for mold clamping while performing feedback control, and between the surface of the resin molding and the mold cavity 53 surface. After providing the gap, the coating material is injected by the control signal transmitted from the injector control unit 35 in accordance with the injection amount, injection speed, injection timing, and injection pressure of the coating material injector 55 set in the mold clamping condition setting unit 32. The machine 55 is driven to inject the coating composition (B) as a coating agent into the mold cavity 53.

  Subsequently, while the feedback control is performed by the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping, the movable mold 52 is advanced again by the mold clamping cylinder 13 and is set in the mold clamping condition setting unit 32. The mold clamping force is generated according to the molding condition data of the mold clamping force. In this way, it is possible to spread the injected coating composition (B) over the entire surface of the resin molded product and to provide optimum pressure conditions for the appearance and adhesion strength of the coating film.

  Since the mold temperature is maintained at a temperature at which the coating composition (B) is cured, the coating composition (B) is cured while being held with the set clamping force. At this time, since the coating composition (B) is cured while being pressed against the mold surface, the surface condition of the mold is accurately transferred to the coating film surface of the coating composition (B). Become.

Thereafter, the mold clamping cylinder 13 is controlled according to the operation timing and mold opening speed pattern set in the mold clamping condition setting unit 32 while performing feedback control by the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping. Thus, the movable mold 52 is retracted to a predetermined mold opening position, and the molded body covered with the coating composition (B) is taken out from the mold apparatus 50.
Thus, one cycle is completed.

  As described above, the second manufacturing method using the injection compression molding method can reduce the residual stress remaining in the molded product, so that the molded product is less likely to be deformed after molding. The in-mold coated molded body is a preferred embodiment because it deforms even a little after molding and has a great adverse effect on the surface appearance.

  Finally, a third manufacturing method of the in-mold coated molded body according to the present invention will be described with reference to FIG.

A third manufacturing method of the in-mold coated molding (injection press molding method)
In-mold coating method used)
The mold clamping cylinder 13 moves the movable mold according to the mold closing speed pattern set in the mold clamping condition setting unit 32 while performing feedback control with the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping. The mold 52 is advanced from the mold opening limit position, and is stopped at a position where a predetermined distance is provided between the mold 52 and the fixed mold 51. At this time, the movable mold 52 and the fixed mold 51 are below the melting point of the polypropylene resin (i) in the hydroxyl group-containing polypropylene resin composition (A), and after the coating agent is injected, the coating agent is the mold. It is kept at a suitable temperature so as to cure inside. The mold device 50 described here has a structure in which the split surface has a shear edge structure, so that the paint does not leak from the split surface even when the mold is slightly opened at the time of resin filling and coating agent injection. did.

  When the screw 21 is advanced by the injection cylinder 24 while controlling the opening degree of the injection servo valve 27 by a control signal transmitted from the injection control unit at a predetermined operation timing during the operation of the mold clamping device 10, the screw 21 The molten resin stored in front of the resin (the resin composition (A)) is injected into the mold cavity 53 via the nozzle 26. The operation timing signals are exchanged by the molding device control unit 31 so that the operation of the mold clamping device 10 and the operation of the injection device 20 are linked.

  In the third manufacturing method using the injection press molding method, the molten resin is injected in a state where the fixed mold 51 and the movable mold 52 are not clamped and kept at a predetermined interval. . While the molten resin is being injected into the mold cavity or after the injection of the molten resin is completed, feedback control is performed by the control signal transmitted from the mold clamping control unit 33 and the mold clamping servo valve 15. In accordance with the mold clamping force molding condition data signal (mold clamping force change pattern) set in the mold clamping condition setting unit 32, the movable mold 52 is further advanced by the mold clamping cylinder 13 to a predetermined mold clamping force. .

  The advantage of using the injection press molding method is that the molten resin is injected with a predetermined amount of mold open, so the flow pressure of the resin is greatly reduced, and the residual stress remaining in the molded product is much higher than with normal injection molding. Very few. Then, by applying a predetermined clamping force during injection or after completion of injection, the resin pressure generated at the end of the molded product can be made higher than in normal injection molding. For these reasons, the thickness of the molded product can be made more uniform than in the case of normal injection molding. After a predetermined clamping force is applied, the molten resin is solidified while maintaining the clamping force.

When the resin in the mold is solidified to some extent and the surface can withstand the injection pressure of the coating composition (B), which is a coating agent, the movable mold 52 is then moved backward by the mold clamping cylinder 13. The mold opening amount set in the mold clamping condition setting unit 32 is given by feedback from the control signal transmitted from the clamping control unit 33 and the servo valve 15 for mold clamping, and the surface of the resin molding and the mold cavity 53 are provided. After the gap is provided between the surface and the surface, control is sent from the injector control unit 35 according to the injection amount, injection speed, injection timing, and injection pressure of the coating agent injector 55 set in the mold clamping condition setting unit 32. The coating material injector 55 is driven by the signal to inject the coating composition (B) into the mold cavity 53.

  Subsequently, while the feedback control is performed by the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping, the movable mold 52 is advanced again by the mold clamping cylinder 13 and is set in the mold clamping condition setting unit 32. The mold clamping force is generated according to the molding condition data of the mold clamping force. In this way, it is possible to spread the injected coating composition (B) over the entire surface of the resin molded product and to provide optimum pressure conditions for the appearance and adhesion strength of the coating film.

  Since the mold temperature is maintained at a temperature at which the coating composition (B) is cured, the coating composition (B) is cured while being held with the set clamping force. At this time, since the coating composition (B) is cured while being pressed against the mold surface, the surface condition of the mold is accurately transferred to the coating film surface of the coating composition (B). Become.

  Thereafter, the mold clamping cylinder 13 is controlled according to the operation timing and mold opening speed pattern set in the mold clamping condition setting unit 32 while performing feedback control by the control signal transmitted from the mold clamping control unit 33 and the servo valve 15 for mold clamping. Thus, the movable mold 52 is retracted to a predetermined mold opening position, and the molded body covered with the coating composition (B) is taken out from the mold apparatus 50. Thus, one cycle is completed.

  As described above, the third manufacturing method using the injection press molding method can reduce the residual stress remaining in the molded product and can form the thickness of the molded product more uniformly than normal injection molding. It has an excellent effect of being able to.

Therefore, the in-mold coated molded body manufactured by the third manufacturing method is a good in-mold coated molded body in that the deformation is small and the coating thickness is more uniform than the conventional one.
[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited at all by these Examples.

  The polypropylene resin compositions used in Examples and Comparative Examples were mixed in the proportions shown in Table 1 below and melt mixed in a twin-screw extruder set at a cylinder temperature of 200 ° C. A pellet-shaped polypropylene resin composition was obtained by underwater cutting. Table 1 shows the hydroxyl value and rubber component content of the composition obtained.

In addition, although the polypropylene resin composition (P-1)-(P-8) in Table 1 is the hydroxyl group containing polypropylene resin composition (A) in this invention, a polypropylene resin composition (Q-1). ) To (Q-3) are not the resin composition (A) used in the present invention.
<Ingredients shown in Table 1>
(1): Propylene block copolymer [MFR (ASTM D 1238, 230 ° C, load 2.16 kg)
= 23 g / 10 min, ethylene / propylene copolymer content = 11% by mass, ethylene content of ethylene / propylene copolymer = 46 mol%]
(2): 100 g / 10 min melt flow rate (MFR; ASTM D 1238, 230 ° C., load 2.16 kg) obtained by modifying a propylene homopolymer with hydroxymethyl methacrylate by the melt modification method Hydroxyl-containing propylene homopolymer (3) having a value of 15 (KOH mg / g): Hydroxyl-containing rubber [trade name: Polytail H, manufactured by Mitsubishi Chemical Corporation, hydroxyl value = 45
(KOH mg / g)]
(4): Hydroxyl group-containing low molecular weight polypropylene [trade name: Umex 1210, manufactured by Sanyo Chemical Industries, Ltd., hydroxyl value = 54 (KOH mg / g)]
(5): Ethylene / 1-butene copolymer [Mooney viscosity ML _{1 + 4} (100 ° C.) = 16, ethylene concentration = 82 mol%]
(6): Linear low density polyethylene [trade name Evolue SP0540, manufactured by Mitsui Sumitomo Polyolefin Co., Ltd., MFR (ASTM D 1238, 190 ° C., load 2.16 kg) = 4.0 g / 10 min, density = 0.905 g / Cm ³ ]
(7): Talc (average particle size = 2 μm)
(8): Phenol-based heat stabilizer [trade name: Irganox 1010, manufactured by Ciba Specialty Chemicals]
(9): Phosphorus heat stabilizer [trade name: Irgafos 168, manufactured by Ciba Specialty Chemicals]

Moreover, about the coating composition for a metal mold | die coating | cover used by the Example and the comparative example, in the ratio shown in Table 2, the following each component except an organic peroxide and a polyisocyanate compound was used in 3 roll mills. The mixture was kneaded and dispersed to obtain a paint base. Next, the following organic peroxide and polyisocyanate compound were added to the paint base in the proportions shown in Table 2, and mixed well to prepare a coating composition for coating in the mold.

In addition, although coating composition (A-1)-(A-8) in Table 2 is the coating composition (B) for in-mold coating in this invention, coating composition (B-1)-( B-8) is not the coating composition (B) used in the present invention.
<Ingredients shown in Table 2>
(1) Oligomer having (meth) acrylate group 1) UAC-1
1000 parts by weight of polycaprolactone diol (molecular weight 500), 840 parts by weight of isophorone diisocyanate, 1.0 part by weight of hydroquinone monomethyl ether and 1.8 parts by weight of dibutyltin laurate are placed in a reactor and reacted at 75 ° C. with stirring for 3 hours. Then, 228 parts by mass of hydroxyethyl acrylate and 0.5 part by mass of hydroquinone monomethyl ether were added and reacted at 75 ° C. for 4 hours to give a urethane acrylate oligomer (UAC) having a weight average molecular weight (Mw) of 3000 having two acrylate groups. -1) was prepared.
2) Ebecryl EB350 (trade name)
Silicon diacrylate oligomer having two acrylate groups (Daicel UCB)
(2) Ethylenically unsaturated monomer 1) 1,6-hexanediol diacrylate 2) Polypropylene glycol diacrylate (3) (Meth) acryl-modified chlorinated polyolefin 1) PP-1
Super-Clon 223M (trade name; manufactured by Nippon Paper Industries Co., Ltd.) with solvent removed (chlorine content 5 mass%)
2) PP-2
Super Clone 224H (trade name; manufactured by Nippon Paper Industries Co., Ltd.) with solvent removed (chlorine content 12.8% by mass)
3) PP-3
Hard solvent KH-4021 (trade name; manufactured by Toyo Kasei Co., Ltd.) with solvent removed (chlorine content 17% by mass)
(4) Organic peroxide 1) Bis (4-t-butylcyclohexyl) peroxydicarbonate 2) t-amylperoxy-2-ethylhexanoate (5) Polyisocyanate compound 1) 2-isocyanatoethyl- 2,6-diisocyanate caproate 2) tris (6-isocyanatohexyl) isocyanurate (6) colored pigment Shinkasha red Y RT-759-D (trade name); quinacridone organic pigment, manufactured by Ciba Geigy (7) Release agent 1) Zinc stearate 2) ZELEC-NE (trade name)
Neutralizing phosphate alcohol (DuPont)
(8) Curing accelerator 8% cobalt octoate

[Examples 1 to 22 and Comparative Examples 1 to 11]
A box-shaped mold coating mold (projection area of about 400 cm ² ) was attached to an in-mold coating toggle injection molding machine having a mold clamping capability of 350 tf with a coating material (paint) injection device attached. Then, a mold clamping force of 200 tf was applied to clamp the mold, and in this state, the mold cavity was filled with a polypropylene resin composition heated to 180 ° C. at an injection rate of 100 cc / sec, and a holding pressure of 40 MPa was applied. It took 2 seconds. The mold temperature at this time was set to 100 ° C. where the paint was cured by the circulating water of the pressurized water mold temperature controller. The polypropylene resin composition filled in the cavity was cooled in a mold for 90 seconds with a clamping force applied, and solidified to such an extent that the surface could withstand the flow of the coating agent.

  Next, the mold is opened by 0.2 mm, and the coating composition is filled between the molded product surface and the mold cavity surface with a pressure of 15 MPa from a paint injection machine attached to the mold, and the mold is closed again. After holding the mold clamping force of 10 tf for 120 seconds to cure the coating composition, the mold was opened and the molded body was taken out.

  The state of the coating film was evaluated by visually observing the cured state of the coating film coated on the surface of the molded body, the presence of bubbles, and the presence or absence of defective coating. The results are shown in Table 3.

Moreover, about the molded object immediately after shaping | molding, the appearance state of the coating film swelling, the peeling state of a coating film, the surface gloss of a coating film, etc. were observed visually, and the external appearance of the molded object immediately after shaping | molding was evaluated. The results are shown in Table 3. Further, the adhesion (adhesiveness) (1) and (2) of the coating film was evaluated according to the following methods. The results are shown in Table 3.
(1) Initial coating film adhesion The initial coating film adhesion test was carried out according to JIS K 5600 Part 5: Mechanical properties of coating film, Section 6: Adhesion (cross-cut method). The adhesion of the coating film was evaluated on the basis of the following 0 to 5 based on the classification of the test results described in JIS K 5600.

<6-level evaluation>
0 ... The edges of the cuts are completely smooth, and there is no peeling in the eyes of any lattice.
1 ... Slight peeling of the coating film at the intersection of cuts.
It is clearly not more than 5% that the crosscut is affected.
2. The coating film is peeled along the edge of the cut and / or at the intersection.
It is clearly more than 5% but more than 15% that is affected by the crosscut part.
There is nothing.
3. The coating has been partially or completely peeled along the edge of the cut,
And / or various parts of the eye are partially or wholly peeled off.
It is clearly over 15% but more than 35% that is affected by the cross-cut part.
Never happen.
4 ··· The coating has been partially or fully peeled along the edges of the cut,
And / or some eyes have been partially or wholly peeled off. Cross bracket
It is clearly not more than 35% that is affected in
5 ... Degree of peeling that cannot be classified even in category 4.

(2) Coating film adhesion after water resistance test JIS K 5600 Part 6: Chemical properties of coating film, Section 2: Liquid resistance (water immersion method), test specimens in warm water of 40 ± 1 ° C Soaked for 240 hours. After completion of the prescribed test period, the test piece was taken out and allowed to stand at room temperature for 24 hours, and the adhesion of the coating film was evaluated in the above-mentioned 6 stages of 0 to 5 according to the classification of the test results described in the method of JIS K 5600.
[Examples 23 to 24]
A box-shaped mold coating mold (projection area 400 cm ² ) was attached to a toggle injection molding machine for in-mold coating molding having a mold clamping capacity of 350 tf with a coating material (paint) injection device attached. Then, a mold clamping force of 100 tf is applied as a primary mold clamping force, and a polypropylene resin composition heated to 180 ° C. is injected into the mold cavity in this state. During the injection filling of the resin composition, the primary mold clamping force is defeated by the filling pressure of the resin composition, and the split surface of the mold is slightly opened. Simultaneously with the completion of injection, the clamping force was increased to 200 tf as the secondary clamping force. The mold internal pressure at the center of the mold when the secondary mold clamping force was applied was 40 MPa. The mold temperature at this time was set to 100 ° C. at which the coating material was cured by the circulating water of the pressurized water mold temperature controller.

  The polypropylene resin composition filled in the cavity was cooled in the mold for 90 seconds with the secondary clamping force applied, and solidified to such an extent that the surface could withstand the flow of the coating agent.

  Next, the mold is opened by 0.2 mm, and the coating composition is filled between the molded body surface and the mold cavity surface with a pressure of 15 MPa from a paint injection machine attached to the mold, and the mold is closed again. After holding the mold clamping force of 10 tf for 120 seconds to cure the coating composition, the mold was opened and the molded body was taken out.

Hereinafter, the extracted molded body was evaluated in the same manner as in Example 1. The results are shown in Table 3.
[Examples 25 to 26]
A box-shaped mold coating mold (projection area 400 cm ² ) was attached to a toggle injection molding machine for in-mold coating molding having a mold clamping capacity of 350 tf with a coating material (paint) injection device attached. Then, the polypropylene resin composition heated to 180 ° C. is injected into the mold cavity with the 5 mm mold opened as the initial mold opening amount, the mold is closed simultaneously with the completion of the injection, and the mold clamping force is increased to 200 tf. I let you. The time required to increase the clamping force to 200 tf after the completion of injection was about 1 second. The mold internal pressure at the center of the mold when the mold clamping force was applied was 60 MPa. The mold temperature at this time was set to 100 ° C. at which the coating material was cured by the circulating water of the pressurized water mold temperature controller.

  The polypropylene resin composition filled in the cavities was cooled in a mold for 90 seconds with a clamping force applied, and solidified to the extent that the surface could withstand the flow of the coating agent.

  Next, the mold is opened by 0.3 mm, and the coating composition is filled between the molded body surface and the mold cavity surface with a pressure of 10 MPa from a paint injection machine attached to the mold, and the mold is closed again. After holding the mold clamping force of 10 tf for 120 seconds to cure the coating composition, the mold was opened and the molded body was taken out.

  Hereinafter, the extracted molded body was evaluated in the same manner as in Example 1. The results are shown in Table 3.

FIG. 1 is an explanatory view showing the overall configuration of an in-mold coating forming apparatus used in the method for manufacturing an in-mold covering molded body according to the present invention.

Explanation of symbols

10: Clamping device 11: Fixed platen 12: Movable platen 13: Clamping cylinder 14: Tie rod 15: Clamping servo valve 16: Stroke sensor 17: Die opening sensor 18: Clamping force sensor 20: Injection device 21: Screw 22: Barrel 23: Hydraulic motor 24: Injection cylinder 25: Hopper 26: Nozzle 27: Servo valve for injection 30: Control device 31: Molding device control unit 32: Clamping condition setting unit 33: Clamping control unit 34: Change Pattern storage unit 35: injection machine control unit 38: injection control unit 50: mold apparatus 51: fixed mold 52: movable mold 53: mold cavity 54: coating agent pressure sensor 55: coating agent (paint) injection machine 100 : In-mold coating molding equipment

Claims (9)

The surface of the molded product composed of the hydroxyl group-containing polypropylene-based resin composition (A) is a molded product coated with the coating composition for in-mold coating (B),
The hydroxyl group-containing polypropylene resin composition (A) is an additive rubber selected from the group consisting of polypropylene resin (i), ethylene / α-olefin copolymer and SEBS (styrene-ethylene / butylene-styrene block copolymer) ( A linear chain obtained by copolymerizing ii) with an α-olefin polymer other than the optionally added polypropylene resin (i) and the added rubber (ii) , and ethylene and an α-olefin having 4 to 20 carbon atoms. A high molecular compound (iii) selected from the group consisting of linear low-density polyethylene , the total hydroxyl value of which is 1 to 40 (K
OH mg / g),
Rubber component content in the hydroxyl group-containing polypropylene-based resin composition (A) (added rubber (ii) amount, polypropylene resin (i) component, and optionally 23 ° C. n-decane of the polymer compound (iii) The total amount of the soluble component) is 15 to 80% by mass when the total content of the rubber component and the resin component other than the rubber component is 100% by mass,
The coating composition for in-mold coating (B)
10-70% by mass of an oligomer selected from the group consisting of urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, polyether (meth) acrylate and silicon (meth) acrylate , and copolymerizable with the oligomer With respect to 100 parts by mass of the vehicle component (a) consisting of 90 to 30% by mass of an ethylenically unsaturated monomer,
(Meth) acryl-modified chlorinated polyolefin (b) having a chlorine content of 2 to 40% by mass, 5 to 35 parts by mass,
An in-mold coated molded article comprising 0.5 to 5 parts by mass of an organic peroxide polymerization initiator (c) and 2 to 20 parts by mass of a polyisocyanate compound (d). The hydroxyl group-containing polypropylene resin composition (A) is
20 to 95% by mass of at least one polypropylene selected from propylene homopolymer, propylene block copolymer and propylene random copolymer as polypropylene resin (i);
5-80% by mass of added rubber (ii) selected from the group consisting of ethylene / α-olefin copolymer and SEBS (styrene-ethylene / butylene-styrene block copolymer) (of polypropylene resin (i) and added rubber (ii)) The total is 100% by mass), and at least one of the polypropylene resin (i) and the added rubber (ii) has a hydroxyl group, and the hydroxyl value is in the range of 1 to 40 (KOH mg / g). The in-mold coated molded article according to claim 1, which is a resin composition. The hydroxyl group-containing polypropylene resin composition (A) is
20 to 95% by mass of at least one polypropylene selected from propylene homopolymer, propylene block copolymer and propylene random copolymer as polypropylene resin (i);
5-80% by mass of added rubber (ii) selected from the group consisting of ethylene / α-olefin copolymer and SEBS (styrene-ethylene / butylene-styrene block copolymer) (of polypropylene resin (i) and added rubber (ii)) The total is 100% by mass)
Α-olefin polymer other than polypropylene resin (i) and additive rubber (ii) , and ethylene and α having 4 to 20 carbon atoms with respect to 100% by mass in total of the polypropylene resin (i) and additive rubber (ii) A polymer compound (iii) selected from the group consisting of linear low-density polyethylene copolymerized with olefin , comprising 1 to 60% by mass, said polypropylene resin (i), additive rubber (ii) and polymer compound (Iii)
2. The in-mold coated article according to claim 1, wherein at least one of the resin compositions is a resin composition having a hydroxyl group and having a hydroxyl value in the range of 1 to 40 (KOH mg / g).   The in-mold coating product according to claim 1, wherein the hydroxyl group-containing polypropylene resin composition (A) is a polypropylene resin composition containing a hydroxyl group-containing polypropylene. The added rubber (ii) in the hydroxyl group-containing polypropylene resin composition (A) is ethylene · α
5. An in-mold coated article according to any one of claims 1 to 4, which is an olefin copolymer.   The in-mold coated molded body according to any one of claims 1 to 5, wherein the hydroxyl group-containing polypropylene resin composition (A) contains an inorganic filler.   The coating composition for in-mold coating (B) according to claim 1, having a melting point of the polypropylene resin component in the hydroxyl group-containing polypropylene resin composition (A) according to any one of claims 1 to 6 or less. The resin composition (A) is melted in the mold cavity in a state where a mold composed of a fixed mold and a movable mold that maintain the mold temperature above the curing temperature is held at a predetermined mold clamping pressure. After injecting the product and holding the pressure for a predetermined time to cool and solidify the melt so as to withstand the flow pressure of the coating composition (B), the mold is slightly opened, and the resulting molded product is obtained. A space is formed between the surface of the mold cavity and the mold cavity, the coating composition (B) is injected into the space, the mold clamping pressure is increased again and the mold is clamped, and the coating composition is held. A method for producing an in-mold coated molded body, wherein the molded body is taken out after (B) is cured. The coating composition for in-mold coating (B) according to claim 1, having a melting point or less of the polypropylene resin component in the hydroxyl group-containing polypropylene resin composition (A) according to any one of claims 1 to 6. The resin composition (A) is contained in the mold cavity in a state in which a mold composed of a fixed mold and a movable mold that maintain the mold temperature above the curing temperature is held at a predetermined primary mold clamping pressure. Injecting the melt, raising the mold clamping force to the secondary mold clamping force during or after injection, and holding it for a predetermined time to cool and solidify the melt to the extent that it can withstand the flow pressure of the coating composition (B) Then, the mold is slightly opened to form a space between the obtained molded product and the mold cavity surface, the coating composition (B) is injected into the space, and the mold clamping pressure is again applied. The mold is clamped and held, and after the coating composition (B) is cured, Method for producing a mold coating forming body characterized by taking out the body.   The coating composition for in-mold coating (B) according to claim 1, having a melting point or less of the polypropylene resin component in the hydroxyl group-containing polypropylene resin composition (A) according to any one of claims 1 to 6. In a state where a predetermined amount of a mold composed of a fixed mold and a moving mold that keeps the mold temperature above the curing temperature is opened, a melt of the resin composition (A) is injected into the mold cavity, The mold clamping force is increased to a predetermined mold clamping force during injection or after completion of injection, and is held for a predetermined time to cool and solidify the melt so as to withstand the flow pressure of the coating composition (B), and then mold Is slightly opened to form a space between the obtained molded product and the mold cavity surface, the coating composition (B) is injected into the space, and the mold clamping pressure is increased again to clamp the mold. Hold the state as it is, and take out the molded body after the coating composition (B) is cured. Method for producing a mold coating forming material, characterized in that.