A laminate comprising: a layer of an adhesive resin composition comprising a resin composition and a polyolefin, a layer of a polar resin, and a layer of an outer layer resin or a recovered resin; wherein the layer of the adhesive resin composition is positioned between the layer of the polar resin and the layer of the outer layer resin or the recovered resin: wherein the resin composition is produced by mixing a resin having an unsaturated carboxylic acid anhydride component with a ring-opening polymer or condensation polymer component having a hydroxyl group or an amino group at both ends or at one end or graft-reacting the component with the component: wherein when mixing the component with the component, potassium acetate, potassium hydroxide or sodium hydrogen carbonate is further added as an accelerant; wherein an amount of the component is such that an acid value of the resin composition is from 0.1 to 50 mg KOH/g with a potassium hydroxide/ethanol solution, and an amount of the component is such that y/(x + y)*100 is 10 or more, where x is a sum of peak heights of peaks (1713 cm -1, 1780 cm -1) derived from an acid anhydride group and y is a height of a peak (1740 cm -1) derived from an ester group, all peaks determined by infrared ray absorption spectrum measurement after melt-kneading the resin composition at 220°C for 5 minutes and then cooled to room temperature; and wherein the amount of the component is from 0.5 to 15 mol% relative to the amount of the component. a layer of an adhesive resin composition comprising a resin composition and a polyolefin, a layer of a polar resin, and a layer of an outer layer resin or a recovered resin; wherein the layer of the adhesive resin composition is positioned between the layer of the polar resin and the layer of the outer layer resin or the recovered resin: wherein the resin composition is produced by mixing a resin having an unsaturated carboxylic acid anhydride component with a ring-opening polymer or condensation polymer component having a hydroxyl group or an amino group at both ends or at one end or graft-reacting the component with the component: wherein when mixing the component with the component, potassium acetate, potassium hydroxide or sodium hydrogen carbonate is further added as an accelerant; wherein an amount of the component is such that an acid value of the resin composition is from 0.1 to 50 mg KOH/g with a potassium hydroxide/ethanol solution, and an amount of the component is such that y/(x + y)*100 is 10 or more, where x is a sum of peak heights of peaks (1713 cm -1, 1780 cm -1) derived from an acid anhydride group and y is a height of a peak (1740 cm -1) derived from an ester group, all peaks determined by infrared ray absorption spectrum measurement after melt-kneading the resin composition at 220°C for 5 minutes and then cooled to room temperature; and wherein the amount of the component is from 0.5 to 15 mol% relative to the amount of the component. wherein the resin composition is produced by mixing a resin having an unsaturated carboxylic acid anhydride component with a ring-opening polymer or condensation polymer component having a hydroxyl group or an amino group at both ends or at one end or graft-reacting the component with the component: wherein when mixing the component with the component, potassium acetate, potassium hydroxide or sodium hydrogen carbonate is further added as an accelerant; wherein an amount of the component is such that an acid value of the resin composition is from 0.1 to 50 mg KOH/g with a potassium hydroxide/ethanol solution, and an amount of the component is such that y/(x + y)*100 is 10 or more, where x is a sum of peak heights of peaks (1713 cm -1, 1780 cm -1) derived from an acid anhydride group and y is a height of a peak (1740 cm -1) derived from an ester group, all peaks determined by infrared ray absorption spectrum measurement after melt-kneading the resin composition at 220°C for 5 minutes and then cooled to room temperature; and wherein the amount of the component is from 0.5 to 15 mol% relative to the amount of the component. wherein when mixing the component with the component, potassium acetate, potassium hydroxide or sodium hydrogen carbonate is further added as an accelerant; wherein an amount of the component is such that an acid value of the resin composition is from 0.1 to 50 mg KOH/g with a potassium hydroxide/ethanol solution, and an amount of the component is such that y/(x + y)*100 is 10 or more, where x is a sum of peak heights of peaks (1713 cm -1, 1780 cm -1) derived from an acid anhydride group and y is a height of a peak (1740 cm -1) derived from an ester group, all peaks determined by infrared ray absorption spectrum measurement after melt-kneading the resin composition at 220°C for 5 minutes and then cooled to room temperature; and wherein the amount of the component is from 0.5 to 15 mol% relative to the amount of the component.