JP4052231B2 - Molding method of resin molded product with skin material - Google Patents

Description

  The present invention relates to a method for molding a resin molded product with a skin material by setting the skin material on a mold.

  A resin molded product with a skin for automobile interiors (for example, a pillar interior product) is set by placing a skin material such as a cloth or a resin sheet on a mold, and filling the mold with a base resin by injection molding, stamping molding, or the like. At the same time that the material is molded, it is manufactured by being bonded to the skin material. Conventionally, these skin materials and base resin have been problematic from the viewpoint of environmental protection because they have been difficult to dispose of and dispose of, because resins that hardly decompose in the natural environment have been used as materials.

Therefore, as a countermeasure against this, the use of biodegradable resins that are decomposed by microorganisms in the natural environment as a skin material or a base material resin has been studied. Recently, a biodegradable resin suitable as a foam material used inside the skin material has been researched and developed. For example, Patent Document 1 discloses a biodegradable aliphatic polyester having a gel fraction of 50% or more. And / or a foam comprising the modified product (typically a polylactic acid resin) is disclosed. Further, in Patent Document 1, a skin (including a biodegradable aliphatic polyester and / or a modified product thereof) is bonded to one surface of the foam, and a thermoplastic resin (biodegradable) is attached to the opposite surface. A molded article in which a base material made of an aliphatic polyester and / or the modified product is integrally molded is described. As the foam in this case, a foam having a thickness of 1 to 10 mm and an expansion ratio of 5 to 30 times is described.
JP 2003-246036 A

  The present inventors pay attention to the technique of the above-mentioned Patent Document 1, and a skin material that is a composite material composed of a woven fabric skin made of polylactic acid resin fiber yarn and a foam made of polylactic acid resin bonded to the back surface thereof. Prototype. And when this skin material is set in the skin material side mold, and a base material made of polylactic acid resin is filled into the cavity between the base material side mold and the skin material by injection, the base material is molded. At the same time, it was pasted and integrated with the skin material, and when a prototype of the resin molded product with the skin material was made, it was found that there were the following problems to be solved.

(A) The surface appearance of the skin material is likely to deteriorate. The polylactic acid resin has a glass transition point (Tg) of 55 to 70 ° C and a melting point of 160 to 180 ° C. For this reason, when the surface of the skin material is pressed against the mold on the skin material side at a mold temperature of about 80 ° C. during the injection molding of the base material, the surface of the woven fabric skin made of polylactic acid resin fiber yarn is softened by heating due to the mold temperature. Then, the fine shape of the woven fabric was crushed and deformed, and the surface appearance was lowered. This problem is the same when a resin sheet with a grain pattern made of polylactic acid resin is used in place of the woven cloth skin, and the grain appearance is distorted and the surface appearance is lowered. The reason why the mold temperature is set to about 80 ° C. is that the base resin made of polylactic acid resin needs to be maintained at a predetermined temperature or higher in the mold as described below.

(B) The physical properties of the substrate cannot be obtained sufficiently, and annealing after removal is required. Polylactic acid resin, which is a crystalline resin, is greatly affected by the crystallinity, and if the crystallinity is low, Since the physical properties are impaired, it is necessary to increase the degree of crystallinity of the polylactic acid resin used as the substrate resin. For this purpose, it is necessary to keep the polylactic acid resin as the substrate resin at a predetermined temperature or higher in the mold, and specifically, it is necessary to set the mold temperature sufficiently high. However, as described above, when the mold temperature is increased, the surface appearance of the skin material is lowered, so that the temperature has to be about 80 ° C. For this reason, the degree of crystallinity of the polylactic acid resin is difficult to increase, and the physical properties of the substrate cannot be obtained sufficiently. Therefore, it has been necessary to anneal the resin molded product with the skin material taken out of the mold.

  The object of the present invention is to solve the above-mentioned problems and sufficiently obtain the physical properties of a substrate mainly composed of a crystalline biodegradable resin without deteriorating the surface appearance of the skin material mainly composed of the biodegradable resin. Another object of the present invention is to provide a method for molding a resin molded product with a skin material.

In order to solve the above-mentioned problems, the present invention sets a skin material in a mold on the skin material side, and fills the inside of the mold (cavity) between the mold on the base material side and the skin material with a base material resin. In the molding method of the resin molded product with the skin that is bonded and integrated with the skin material at the same time as molding the base material,
Use the skin material mainly composed of biodegradable resin,
Set the mold temperature of the skin material side mold below the glass transition point of the biodegradable resin of the skin material,
Use a resin mainly composed of crystalline biodegradable resin as the base resin,
The substrate is molded by setting the mold temperature of the mold on the substrate side to be equal to or higher than the glass transition point of the biodegradable resin of the substrate resin.

  Here, the biodegradable resin may be the same as or different from that used for the skin material and that used for the base material. The glass transition point of the skin material (special skin in the case of a composite as described later) and each biodegradable resin of the base material is not particularly limited, but it is preferably 55 to 70 ° C because it is easy to handle. In this case, it is preferable to set the mold temperature of the mold on the skin material side to 10 to 50 ° C. In addition, it is preferable to set the mold temperature of the mold on the substrate side to 90 to 130 ° C. and set the in-mold annealing time for annealing by holding the substrate resin in the mold to 30 to 180 seconds. And after the said holding | maintenance, it is preferable to take out the resin molded product with a skin material, after lowering | hanging the type | mold temperature of the type | mold of the base material side to below the glass transition point of the biodegradable resin of resin for base materials.

  FIG. 6 is a graph showing the relationship between the deflection temperature under load and the degree of crystallinity studied by the present inventors for a polylactic acid resin having a glass transition point (Tg) of 55 to 70 ° C. In a resin molded product with a skin for automobile interiors and the like, the deflection temperature under load is preferably 95 ° C. or higher. However, according to the graph, the degree of crystallinity is set to 95 ° C. or higher for the deflection temperature under load in the polylactic acid. It can be seen that it is necessary to be 85% or more.

  FIG. 7 shows crystallinity and in-mold annealing time (mold) when the present inventors injected the polylactic acid resin into a mold having a resin temperature of 200 ° C. and a mold temperature of 70 ° C., 90 ° C. or 110 ° C. It is a graph which shows the relationship with the time which anneals by being hold | maintained in (inside). According to the graph, in order to achieve a crystallinity of 85% or more, an in-mold annealing time of 38 seconds or more is required at a mold temperature of 110 ° C., and an in-mold annealing time of 99 seconds or more is required at a mold temperature of 90 ° C. It turns out that it is. On the other hand, when the mold temperature was 70 ° C., the crystallinity did not reach 60% even when the in-mold annealing time was extended.

  The present inventors have keenly felt the necessity of making the mold temperature considerably high from the above examination, but then the contradictory problem of deterioration of the surface appearance of the skin material becomes more pronounced as described above. Overcoming was necessary. As a result of further various studies, the present inventors have found that these problems can be overcome by setting the mold temperature of the mold on the skin material side and the mold temperature of the mold on the substrate side, and have reached the present invention.

  That is, by setting the mold temperature of the skin material side mold to be less than the glass transition point of the biodegradable resin of the skin material, there is no possibility that the surface of the skin material pressed against the mold is heated and softened, and the surface appearance is deteriorated. Can be prevented. On the other hand, by setting the mold temperature of the base-side mold to be equal to or higher than the glass transition point of the biodegradable resin of the base resin, cooling of the base resin by the base-side mold can be suppressed, The crystallinity of the base resin can be ensured.

  However, even if the mold temperature of the mold on the base material side is set high, if the mold temperature on the skin material side is low below the glass transition point, the base resin is cooled by the mold on the skin material side and sufficient crystallization is achieved. In some cases, the degree cannot be obtained. In such a case, it is preferable to set the heat insulating property of the skin material so that the heat of the base resin is not taken away by the mold on the skin material side. The mold temperature of the mold on the substrate side and the heat insulating property of the skin material are set in association with each other. That is, by setting the mold temperature of the mold on the base material side and the heat insulating property of the skin material so that the crystallinity of the base material after molding becomes, for example, 85% or more, Keep the crystallinity at the temperature and time to obtain it. Therefore, as long as the crystallinity of the base material after molding is, for example, 85% or more, the balance between the mold temperature setting of the base-side mold and the heat insulating property setting of the skin material is moderate, or moderate For balance, set the temperature of the base material side to a lower level by setting the mold temperature of the base material side higher, or set the temperature of the base material side to the lower level by setting the heat insulating property of the skin material higher. A range of settings can be provided, such as setting the mold temperature lower.

[Biodegradable resin]
Although it does not specifically limit as biodegradable resin, The biodegradable aliphatic polyester disclosed by the said patent document 1 and / or this modified material can be illustrated. Examples of the constituent resin of the biodegradable aliphatic polyester include polylactic acid and the following lactone resins such as ε-caprolactone, β-propiolactone, γ-butyrolactone, δ-valerolactone, enanthlactone and 4-methylcaprolactone. , 2,2,4-trimethylcaprolactone, homopolymers or copolymers of various methylated lactones such as 3,3,5-trimethylcaprolactone, and mixtures thereof, or aliphatic polyesters represented below, For example, an aliphatic polyester obtained by polycondensation of a diol such as ethylene succinate, polybutylene succinate, polybutylene succinate a / adipate, polybutylene succinate carbonate, and the like, or Polyhydroxybutyrate Barrela Natural polymers and the like such as natural linear polyester-based resins and the like.

  In order to increase the heat resistance of these biodegradable aliphatic polyester resins, carbonates may be copolymerized or modified by chain connection with isocyanate, carbodiimide, epoxy groups, or the like.

  The biodegradable resin includes cellulose acetate such as cellulose acetate, cellulose butyrate, cellulose propionate, cellulose nitrate, cellulose sulfate, cellulose acetate butyrate, cellulose nitrate acetate, etc., polyglutamic acid, poly Synthetic polymers of polypeptides such as aspartic acid and polyleucine may be mixed and / or natural polymers such as raw starch such as corn starch, wheat starch and rice starch, acetated starch, methyl Etherified starch, processed starch such as amylose, and the like may be mixed as long as the melt characteristics are not impaired. Moreover, the said biodegradable resin may be used independently and may use 2 or more types together.

  The ratio of the biodegradable resin mainly contained in all resin components in the resin composition is not particularly limited, but is preferably in the range of 50 to 100% by weight. If the amount of biodegradable resin is increased, the decomposition rate is increased and the deformability after decomposition is improved. Resin components other than biodegradable resins are not particularly limited. For example, ultra-low density polyethylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ultra high molecular weight polyethylene, polypropylene, ethylene- Propylene rubber, polyvinyl acetate, polybutene and the like may be added.

Further, the biodegradable aliphatic polyester (especially used for the foam of the surface material) preferably has a gel fraction obtained by a 130 ° C. tetralin solvent extraction method of 50% or more, more preferably 55. ~ 90%. If the gel fraction is too low, it will be crushed by the resin temperature and the resin pressure during integral molding with the substrate, resulting in thinning of the thickness or tearing. In addition, the gel fraction here is a value measured and calculated by the following method. That is, about 50 mg of the biodegradable resin crosslinked foam is accurately weighed, immersed in 25 ml of tetralin at 130 ° C. for 3 hours, filtered through a 200 mesh stainless steel wire mesh, and the insoluble matter on the wire mesh is vacuum dried. . Next, the weight of this insoluble matter is precisely weighed, and the gel fraction is calculated as a percentage according to the following formula.
Gel fraction (%) = {weight of insoluble matter (mg) / weight of weighed biodegradable resin crosslinked foam (mg)} × 100

  In particular, the foaming agent used for the foam made of the biodegradable aliphatic polyester of the surface material is a compound that is liquid or solid at room temperature and decomposes or vaporizes when heated above the melting point of the biodegradable resin. Any material can be used as long as it does not substantially interfere with sheeting or crosslinking reaction. Among these, a pyrolytic foaming agent and a decomposition temperature in the range of 120 ° C. to 270 ° C. are preferable. As a specific example thereof, the one exemplified in Patent Document 1 can be exemplified. Moreover, in order to adjust decomposition temperature, what contains decomposition temperature regulators, such as a zinc oxide, a zinc stearate, urea, can be preferably used for the said foaming agent, for example. In addition, as a crosslinking method for forming a foam, a known ionizing radiation crosslinking method or a chemical crosslinking method using an organic peroxide can be applied, and among them, an electron beam irradiation method using an electron beam accelerator is easy to handle. From the standpoint of ease of setting the degree of crosslinking and the like. In order to suppress the deterioration of the resin and promote crosslinking by the above method, it is preferable to add the crosslinking accelerator exemplified in Patent Document 1 above.

  In addition, you may add additive components other than a foaming agent to the resin composition used for this invention in the range which does not inhibit the effect of this invention. For example, antioxidants, lubricants, heat stabilizers, pigments, flame retardants, antistatic agents, nucleating agents, plasticizers, antibacterial agents, biodegradation accelerators, foaming agent decomposition accelerators, light stabilizers, UV absorbers as additives You may make it add an agent, an antiblocking agent, a filler, a deodorizer, a thickener, a foaming assistant, a foam stabilizer, a metal harm prevention agent etc. individually or in combination of 2 or more types.

[Skin material]
Although it does not specifically limit as a skin material used for this invention, The following can be illustrated.
(1) Skin material which consists only of skin When skin itself is equipped with the heat insulation required by this invention, a skin material can be comprised only with the skin. Examples of such skins include biodegradable resin fibers or fabrics such as thick woven fabrics, nonwoven fabrics, and raised fabrics using the fiber yarns, and sheet-like products made of biodegradable resin foams (integral Examples include those with skins and leather-like ones).

(2) Composite skin material composed of a skin and a heat insulating layer When the skin itself does not have the heat insulating property required by the present invention, or when it is provided, but it is desired to add further heat insulating properties, the skin and its skin A composite skin material composed of a heat insulating layer bonded to the back surface can be formed. Such skins include biodegradable resin fibers or fabrics such as thin or thick woven fabrics, nonwoven fabrics and brushed fabrics using the fiber yarns, sheet materials of biodegradable resins (films and leathers). And the like). Moreover, as a heat insulation layer applicable to this, the sheet-like thing which consists of a foam of a biodegradable resin, the nonwoven fabric using a biodegradable resin fiber, etc. can be illustrated. In particular, when the heat insulating layer is a sheet-like material made of a foam, the thickness is preferably 1 to 10 mm, and the expansion ratio is preferably 5 to 30 times. The foam sheet is preferably made of a biodegradable aliphatic polyester resin, and polybutylene succinate / adipate is particularly preferred because it is flexible and highly elastic.

The skin material may be any of the following.
(A) Soft and easily deformable skin material This skin material may be formed by being pressed against the mold on the skin material side by the pressure of the base material when molding the base material, or by molding the base material It may be preliminarily shaped by being brought into close contact with the mold on the skin material side by vacuum forming, pressure forming or the like. In the latter case, the skin material can be greatly shaped without much stress, so that it becomes easy to deal with deep drawing products.
(A) A skin material pre-shaped in a shape that matches the mold on the skin material side by another mold, means, etc. For example, a skin material pre-shaped with another vacuum forming mold or an insert made of biodegradable resin A skin material using parts can be exemplified.

[Substrate molding method]
Although it does not specifically limit as a shaping | molding method of a base material, The injection molding method, the injection press molding method, a stamping shaping | molding method etc. can be illustrated.

  Therefore, according to the method for molding a resin-molded article with a skin material according to the present invention, a base mainly composed of a crystalline biodegradable resin without reducing the surface appearance of the skin material mainly composed of the biodegradable resin. There is an excellent effect that the physical properties of the material can be sufficiently obtained.

The skin material is set on the mold on the skin material side, the base resin is filled in the mold (cavity) between the mold on the base material side and the skin material, the base material is molded, and at the same time, the base material is pasted In the molding method of the resin molded product with skin to be integrated,
Preferably, the skin material is mainly composed of a biodegradable resin having a glass transition point of 55 to 70 ° C.
The mold temperature of the mold on the skin material side is preferably less than the glass transition point of the biodegradable resin of the skin material, preferably 10 to 50 ° C.,
Preferably, a resin mainly composed of a crystalline biodegradable resin having a glass transition point of 55 to 70 ° C. is used as the base resin.
A mold in which the mold temperature of the mold on the substrate side is set to 90 to 130 ° C. which is equal to or higher than the glass transition point of the biodegradable resin of the substrate resin, and the mold is annealed while holding the substrate resin in the mold The inner annealing time is set to 30 to 180 seconds, and the substrate is molded.
After the holding, the mold temperature of the mold on the base material side is lowered below the glass transition point of the biodegradable resin of the base resin, and then the resin molded product with the skin material is taken out.

  Embodiments of the present invention will be described below with reference to the drawings. A resin-molded article 1 with a skin molded in this embodiment is a pillar interior product of an automobile as shown in FIGS. 1 and 2, and is composed of a skin material 2 and a base material 5. The skin material 2 is a composite composed of a fabric 3 and a heat insulating layer 4 bonded to the back surface thereof.

  The fabric 3 is made of a woven fabric in which yarns made of fibers having a fiber diameter of 1.77 to 11.0 dtex (Decitex) made of polylactic acid resin having a glass transition point of about 68 ° C. and a melting point of about 170 ° C. are used. Yes.

For the heat-insulating layer 4, a foam sheet having a foaming ratio of about 10 times, a density of about 0.1 g / cm ³ and a thickness of about 2 mm, which is also formed of a polybutylene succinate resin having a glass transition point of about −32 ° C. is used. Has been. The foam sheet is formed into a sheet using, for example, a mixture of the polybutylene succinate resin, a foaming agent, and a crosslinking aid, and then the sheet is irradiated with ionizing radiation, and the polybutylene succinate resin is used. It is produced by crosslinking and then heating to a temperature higher than the decomposition temperature of the foaming agent for foaming. As the manufacturing method, for example, the method exemplified in the above-mentioned Patent Document 1 can be adopted.

  The skin material 2 is formed into a composite by bonding the fabric 3 to the surface of the foam sheet thus obtained by a known method such as an adhesive method, a heat roll method, a frame laminating method, and an extrusion laminating method. It is a thing.

  For the base material 5, a polylactic acid resin having a glass transition point of about 68 ° C. and a melting point of about 170 ° C. is used as the base material resin. And the base material 5 of a present Example is shape | molded by the injection molding method as described below.

The above-mentioned resin molded article 1 with a skin is molded by the following method using a mold apparatus as shown in FIG. 3 and controlling the mold temperature as shown in FIGS.
(1) As shown in FIG. 3A, the skin material 2 is set on the PL surface of the mold 10 on the skin material side. At this time, the fabric 3 is directed to the molding surface 11 of the mold 10 on the skin material side, and the heat insulating layer 4 is directed to the molding surface 21 of the mold 20 on the base material side.

(2) At the same time as (1) or before and after (1), a medium liquid at a predetermined temperature is allowed to flow through a temperature adjusting tube (not shown) built in the mold 10 on the skin material side, as shown in FIG. Thus, the mold temperature of the mold 10 is set to about 30 ° C. In addition, by flowing a medium liquid at a predetermined temperature through a temperature adjusting tube (not shown) built in the base-side mold 20, the mold temperature of the mold 20 is changed as shown in FIGS. Is set to about 110 ° C.

(3) After the above (1), as shown in FIG. 3 (b), the mold 10 on the skin material side and the mold 20 on the base material side are put together and clamped and melted at a resin temperature of about 200 ° C. The base material resin 5a is injected from the injection nozzle 25 connected to the base material side mold 20 through the gate 22 into the cavity between the mold surface 21 of the base material side mold 20 and the skin material 2 to be filled. The base material 5 is molded and bonded to the skin material 2 at the same time. In addition, in order to give fluidity | liquidity, the resin temperature inject | emitted is made 20 degreeC or more higher than melting | fusing point of this resin 5a. The in-mold injection pressure is usually 10 to 60 MPa.

As shown in FIG. 5, by maintaining the state after the injection in (3) for a predetermined time, the base resin 5a is annealed in the mold to be crystallized. This in-mold annealing time is about 60 seconds in this embodiment. FIG. 4B conceptually shows the temperature distribution of each part of the resin-molded article 1 with a skin at any point of this in-mold annealing time. That is,
a) Mold temperature of the mold 10 on the skin material side is set to 30 ° C., which is lower than the glass transition point of the polylactic acid resin used for the fabric 3 which is the surface side of the skin material 2 in particular. Since the temperature of at least the surface portion of the fabric 3 pressed against the surface 11 can be suppressed below the glass transition point, there is no possibility that the surface of the fabric 3 is heated and softened, and the surface appearance can be prevented from being deteriorated.

b) On the other hand, by setting the mold temperature of the mold 20 on the substrate side to about 110 ° C. which is equal to or higher than the glass transition point of the polylactic acid resin used for the substrate resin 5a, the substrate resin 5a according to the mold 20 is used. As a result, the in-mold annealing time is set to about 60 seconds, and sufficient crystallization proceeds. However, even if the mold temperature of the mold 20 on the base material side is set high, if the mold temperature 10 on the skin material side is low below the glass transition point, the base resin 5a is cooled to the mold 10 and sufficient. There is a possibility that the crystallinity cannot be obtained. Therefore, in this embodiment, the heat insulating property of the heat insulating layer 4 of the skin material 2 is set so that the heat of the resin 5a for the base material is not taken away by the mold 10 on the skin material side, and the resin 5a for the base material being molded is For example, the temperature and the time at which a crystallinity of 85% or more is obtained are maintained. Therefore, sufficient physical properties of the substrate can be obtained without annealing after removal.

(4) After the above in-mold annealing is completed, a medium liquid at a predetermined temperature is allowed to flow through a temperature adjusting tube (not shown) of the mold 20 on the base material side, so that the mold temperature of the mold 20 is as shown in FIG. Is lower than the glass transition point, for example, to about 50 ° C. to change the softened state of the base material 5 to a cured state, and the molds 10 and 20 are opened, and the resin-molded article 1 with the skin is formed by ejector pins (not shown). Take it apart from the mold 20 and remove it. The reason for lowering the mold temperature in this way is to cure the base material 5 so as not to be deformed when taken out by the ejector pin.

In addition, this invention is not limited to the said embodiment, For example, it can also be suitably changed and embodied as follows, for example in the range which does not deviate from the meaning of invention.
(1) Replacing the fabric 3 with, for example, a design sheet obtained by extruding the polylactic acid resin (molecular weight is preferably 100,000 to 200,000).
(2) In the above-described embodiment, since the same polylactic acid resin is used for each part, for example, the contact surface of the skin material 2 (heat insulating layer 4) and the base material 5 has an affinity / compatibility and is molded. Bonded by heat fusion at the time. However, in the case where there is no affinity / compatibility between them and adhesion is difficult, it is preferable to apply an adhesive to the skin material 2 in advance or to provide a film-like material of hot melt resin.
(3) It is preferable that 1 to 10% by weight of a nanocomposite such as clay is mixed in the base resin 5a to act as a crystal nucleus to ensure a crystallinity of 90% or more.

1 is a perspective view of a resin molded product with a skin (automotive pillar interior product) molded in an example of the present invention. FIG. (A) is the II-II sectional view taken on the line of FIG. 1, (b) is the principal part expanded sectional view of (a). It is sectional drawing which shows the shaping | molding method of the resin molded product with the same skin. (A) is an expanded sectional view of the IVa arrow part of FIG. 3, (b) is the schematic which shows the temperature distribution of (a). It is a time chart which shows the mold temperature of the type | mold of the base material side, and the relationship of time passage. It is a graph which shows the relationship between the deflection temperature under load and the crystallinity degree of polylactic acid resin. It is a graph which shows the relationship between the crystallinity degree of polylactic acid resin, and in-mold annealing time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Plastic molded product with skin material 2 Skin material 3 Fabric 4 Heat insulation layer 5 Base material 5a Base material resin 10 Mold on the skin material side 20 Mold on the base material side

Claims (5)

The skin material is set in the mold on the skin material side, and the base material is filled in the mold between the mold on the base material side and the skin material, and the base material is molded. In the molding method of the resin molded product with a skin to be converted,
Use the skin material mainly composed of biodegradable resin,
The mold temperature of the mold on the skin material side is set below the glass transition point of the biodegradable resin of the skin material,
Using a resin mainly composed of a crystalline biodegradable resin as the base resin,
A molding method for a resin-molded article with a skin material, wherein a mold temperature of a mold on the substrate side is set to be equal to or higher than a glass transition point of a biodegradable resin of the resin for the substrate.   The method for molding a resin molded product with a skin material according to claim 1, wherein the glass transition point of each biodegradable resin of the skin material and the base material is 55 to 70 ° C.   The molding method of a resin molded product with a skin material according to claim 2, wherein a mold temperature of the mold on the skin material side is set to 10 to 50 ° C.   The mold temperature of the mold on the substrate side is set to 90 to 130 ° C, and the in-mold annealing time for annealing by holding the resin for the substrate in the mold is set to 30 to 180 seconds. Or the molding method of the resin molded product with a skin material of 3 description.   The resin molding with a skin material according to claim 4, wherein after the holding, the mold temperature of the base material side mold is lowered below the glass transition point of the biodegradable resin of the resin for the base material, and then the resin molded product with the skin material is taken out. Molding method.

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